Weatronic documentation.

Dear Weatronic users.

I am putting all my documentation online for the community.

It is available here for free download.

This documentation library is still copyrighted and is the intellectual property of Ultimate Jets. However you are free to use it for your own benefits.
Please bear in mind that this represents over 500 hours of hard work and was originally written for our professional and military customers. It includes a comprehensive Gigacontrol user manual, a unique BAT series programming guide, advanced antenna characterisation procedures and so on.

Gigacontrol manual.

BAT UJ programming guide.

BAT Weatronic manual.

Gizmo user manual.

Micro user manual.

Smart user manual.

Clever user manual.

UJ Log reader user manual.


Enjoy the 800 + pages of reading!


Written by Olivier Nicolas — May 13, 2016

Ultimate Log reader

This is just a short article that describes our new program that just went out of beta mode:
The Ultimate Log Reader or ULR.

This is a World unique innovation that will enable you to get a diagnostic of your model systems in a few seconds.

The program was developed by Oistein, with my guidance.
Oistein is the code genius of our team and really is the father of this program.
He will follow up on this here.

The first stage of the program development is finished.
To keep things simple, Weatronic gave me the code to extract the data from the log files. This code was compiled by Oistein in QT libraries and then ported to the Windows platform. We worked on this code for a while, then decided to create our own parser for faster data extraction and elimination of the fake value appearing when discontinuities occur.

The program at this stage does what Gigacontrol is offering right now with the table view and 2D view. However it adds powerful statistical analysis ( Min, Max, mean, median, stdev ).
Furthermore the program has an auto flight extraction. This means that you can load a log in ULR that has a fligth in it. Then the program will extract the meaningful flight data and erase the rest.

The program offer two statistical analysis windows to characterize your flight RF link and your batteries performance ( Rx and Tx ).

At a second stage, domain analysis will be added to establish system fault statistical analysis an system fatigue characterization. This will use my knowledge of airline maintenance software like Airman, Taelis, AHM/ MAT. This uses complex algorithms with domain and data frequency analysis but will not be meaningful until we get enough modelers using the system.

However I can already tell you that this platform will be able to advise you of a turbine problem and what problem is coming up ( warped combustion chamber, clogged injectors, turbine wheel performance degradation, fuel pump problem, igniter problem ). This will be available through our ASSI system that will be compatible with Weatronic telemetry as soon as the engineers from Berlin release the SCU code to us.

The platform will also be able to advise about transmitter and receiver batteries degradation, servo performance degradation, binding flight control, antenna loss of sensitivity and airspace frequency jamming.
The software will also have an automatic antenna diagram detection and antenna placement recommendation.


Here are a few screen caps of the main screens.

The table screen presenting the data line by line according to time stamp and sample number:


The user plot screen that enables you to load the log you want and create 3 custom graphs with any of the data available from the left column.



The Link analysis screen that shows you the performance of your RF link for a given flight. This screen offers the option to extract flights to eliminate unwanted post and pre-flight data ( here shown un-ticked ):



And with the flight data extraction option ticked ( lots of non relevant data removed from the screen ):



On the two previous screens the data is pre-formatted as explained previously to match my method of RF link analysis and conform to the RF link database available on the blog below. Note that LQI mean value for Rx and Tx is computed and will give you a very precise insight on the performance of you RF link for the current flight.


The last screen is for batteries analysis. It will enable you to see the performance of your receiver batteries as well as monitor the health of your transmitter cells.


In the meanwhile, here is the link to the latest version.

Written by Olivier Nicolas — October 24, 2015

MIL spc transmitters.

These will be available in camo scheme i the following colors:







The MIL versions will have the following features:


  • Camo scheme.
  • Carbon fiber casing with synthetic leather pad.
  • Full aluminium gimbals
  • Aluminium rotating knobs
  • The option to connect the radio to our ground station via the Wifi network

and other specific features that are not disclosed yet.


Written by Olivier Nicolas — March 19, 2015

NCFD device for remote control flying.

The market is now mature in terms of telemetry data return.

A large number of devices are available and some of them, like our ASSI unit, offer a very large and unique number of data feedback.

However, there is a large gap between the data available and how to exploit it for RC pilots. Apart from our Android app, very few manufacturer offer a decent way of getting the feedback to us.

Audio return is one way, however it is very well known that in case of high brain workload, hearing is the first sense to disappear.

While flying fast RC jets, it is not uncommon to completely miss audio information from the telemetry system while performing a complicated aerobatic maneuver, or while flying very close to the ground at high speed.

The visual feedback is essential to the pilots as this is the last sense to disappear in high workload/ stress condition. But there is a big obstacle for RC pilot: we need to see what's going on in the sky and we often cannot afford to look down at parameters and loose the sighting of a fast flying tiny aeroplane.

Dual screen configurations are nice and offer un-matched comfort and flexibility in programming, but they are very limited in terms of telemetry ergonomics, because they are head down type. Giving the second screen to your spotter is a very nice solution but it does not answer the request for having a direct feedback to the pilot. Additionally, spotters might also face the challenge of having to both look at your plane and the display.


So the next step is to offer visual feedback close to the central vision field of the pilot.

Real size aviation call this HUD or Head Up Display. A collimated transparent screen display information laid down in front of the pilot's windscreen.

Is this really what we need?

Not exactly. The reason is that our flying objects are often tiny and right in the center of the vision field, where our eye display the highest definition. A few pixels in front of a tiny black dot will completely obliterate the vision of it and specially the contrast and shades that enable us to see if the plane is banking right or left at a distance.

So what is the solution?

Near Center Field Displays.

Our visual field is not uniform and vision definition fades away rapidly from median line of the retina that represents the line-of-sight.

Below is a diagram in 3D showing how fast the vision definition fades away as objects are displaced from this line that ends up at the point-of-fixation.

A projected view of our visual field accuracy would look like this:

The center field is this "island of high definition" that is shown above. It is generally extending from 24 to 30 degrees around the point of fixation.

It extends a bit further on the outer lower corner of each field. This is where we would place a display at best for our RC flying use.

Why below and not above like real size HUD? We, RC pilots need to see whats' going on in the sky, whereas full size pilots need to see what's going on down in the flight deck on their instruments. Our "not-so-vital" zone of vision is the bottom area where the ground is. For real size pilots it is more in the top corner of the sky.

Here is an example of what a NCFD does look like while flying a remote control airplane.



The ground area is usually darker and fairly meaningless in terms of orientation feedback to the brain. As long as the horizon is available, our brain can analyze a fast moving object very fast. Additionally it is usually darker, which is perfect to display LCD generated information that cannot be too bright. The display being very small and less than 1 inch away from the eye, very bright information is not possible.


Do a small experiment: Place yourself close enough to the screen so that you see most of the picture above. Stare at the plane so that it is on your fixation point. Now concentrate on your peripheral vision. How much information do you see on the NCFD?


We conducted a long field trial with different devices like the Google glass and Recon products. What we found out is that see through displays were not suitable for RC pilots because of the loss of resolution incurred while looking through the prism. The best results we had were with the simple and cheaper Recon instruments.

We developed an app for the Recon Jet display and are now offering this device as the World's first near eye display for UAV and RC pilots.



Written by Olivier Nicolas — February 20, 2015

Editing servo curves with the BAT interface.

Editing the servo curve with the BAT UI is a different method than Gigacontrol. As easy to do in fact.
I like presets a lot. Most of the time I come to realize that I just need 4 points along the curve to align multiple flight controls. The preset gives me the ability to edit 4 points on the curve really easily.
Here is the method I use.

First enter the curve edit mode.



Then select the non-global option ( to edit the curve with point, not to move the whole curve ).



Then enter the preset menu.



Select the 4 point curve preset.



Then move the current point along the curve with your stick or knob till you reach the point you want to edit. It will highlight with a thin red circle.




Then hit the "select" button. The highlighted point will turn solid red.



Now you can adjust the output value with the "+" and "-" keys. Note that you will need to keep your stick at the current position to check the effect on the point live.



Every point can be edited quickly with this method.


Written by Olivier Nicolas — November 22, 2014

BAT 60 ergonomics and design.






















Written by Olivier Nicolas — October 16, 2014

The new Weatronic gimbals system.

Here is a new feature post on the BAT series new sticks.

They are so advanced that tey well deserve a long explanation with lots of pictures to illustrate the design.

I have had the chance to try these sticks on demonstration units at different fare and I can tell you thhat there is nothing else in the wolrd that compare to this in term of feeling, precision, feedback and ergonomics.


Lets see why.

The new sticks, feature full aluminium design with 9 precision ball bearings. Large contact surface were made with the transmitter to allow a perfect transmission of the efforts to the casing and a high rigidity of the assembly.

The position sensors are made with Hall effect sensors. The main benfits of this is that there is no contact on the stick position sensor thus no wear and a perfectly replicable result with no drift. The hall effect sensors feature 8096 steps which is way beyond any digital servo resolution.

One can see the sensor boards on the 2 following pictures:

This picture shows the large bronze/ aluminium ball that provides dust sealing at the base of the stick as well as surface contact for a good effort transfer. Additionally to this, a large aluminium plate connects the gimbals to the box ( in plexiglass here for a beter vision of the mechanism ).

The feedback ramp is the white nylon part showing on the following picture. An ball bearing roller provides the stick follow-up/ return on this part. One can see the tension spring on the next picture that keeps the roller pressed to the ramp. The tension is adjustable to a large ratio and will change the return effect/ ratchet effect of the ramp.

Feedback ramps are user replaceable and feature different shapes for different stick feeling:

The CH, CN and CS ramps are typically used for flight controls that require a return to center. CH has the stronger effect, while CN and CS have decreasing effects. Note that the roller tension on the ramp would provide additional centering feedback grades. This is a world premiere and a big difference compared to normal radio gimbals that provide the return feedback from the direct effect of a coil spring ( linear force ).

Here the return force is non linear and strong around the center ( good center feeling when having extra small control inputs around neutral with excellent precision ) while fading away around the extremes.


The CD ramp only has a center click and does not provide any return force.

The ST ramp provides the typical ratchet feeling.

The SL ramp is a neural ramp with no return and no center position.

Most normal radio gimbals provide the return feedback from the direct effect of a coil spring. This gives a linear feedback that is adjusted linearily by the tension of a spring.

Here the return force is logarithmic and strong around the center ( good center feeling when having extra small control inputs around neutral with excellent precision ) while fading away around the extremes. The return spring will adjust the feeling along the whole travel, while different shapes will give you the ability to choose from 3 different logarithmic response curves.

CH has the stronger response curve ( very high centering force, fast fading away ), while CN and CS have decreasing effects. Note that the roller tension on the ramp would provide additional centering feedback grades, thus enabling you to modulate the logarithmic response between the 3 different shapes..

Another world premiere is the MA/ MB ratchet. It provides the effect of a normal ratchetwith 75% of the standard deflection. However the bottom 25% will act on another channel with feedback force. A proximity switch provides the end of ratchet detection ( secondary ramp as shown on the diagram ). This is extremely important to avoid shutting down the engine while moving on the non ratchet ramp.
I see a fantastic potential for this as a speed brake function. You could extend the speed brakes in flight without having to reach another switch.
This can also be used for the brakes on the ground but wwe are all used to reach the slider to activate the brakes. So I think that this function will be much nicer on the speed brakes...

Written by Olivier Nicolas — November 13, 2013

Setting up the MUX box telemetry sensors.

Here is a short description on how to setup the Weatronic MUX box and telemetry sensors on the Weatronic system.

The MUX box is a sensor interface that plugs on the SCU port of the receiver. It enables the receiver to send you the data that is collected by the sensors.

It requires two servo cables to be plugged to the receiver. One goes to the SCU port and the other one to a servo output via a Y cable or to a battery port. The other cable is only just a power supply cable.

On this picture you can see the black "batt" cable at the bottom that goes to the receiver Y servo cable ( power supply ). The blue plug goes to the SCU input slot of the receiver.

Once the MUX box is connected to the receiver, power up the system. You will see the MUX box green and red LEDs flashing for a little while and then, the red should extinguish and the green become steady.

Once this is done, plug the DV4 module to the laptop via the USB port and open up the GigaControl software.

Go o the MUX box tab.

You should see this:

The MUX box 1 tab on the top left has turned green and shows the device type and serial number.

You can now plug the required sensors to the available slots.

The pitot tube:

It is a great little device that works on the Prandtl principle. The front of the tube measures the dynamic pressure, while the annular hole measure an average static pressure around the tube. The rounded shape of the tube front assures that the dynamic pressure is read correctly in a reasonable range of angles of attack.

The back of the pitot tube will be connected to the pressure sensor by two very tiny silicone tubes. One is blue and connect to the blue nipples, whereas the other one is white an connects to the non colored nipples. It is essential to ensure that the silicon tubes are not pinched when installing them.

The  pressure sensor is a very tiny little cube with a servo plug on its back.

The servo plug HAS to connect to the A1 input of the MUX box as this is the only input that accepts this device.

The pitot tube has to be installed in a free flow environment, as streamlined as possible and at least 40 cm away from any fuselage surface. The best location for a jet is a the front of the nose. Make sure that the pitot tube is aligned vertically and horizontally with the symmetry axis of the fuselage.

Note that when you are at the field and switch the receiver ON, the pitot system goes through a boot up sequence and zeroes. It is important at that point to keep it protected from any wind interference. I found out that putting an open cells foam hood on the pitot before switching ON was doing the trick.

To make sure that the zero was done properly, I have a little trick: just place the model nose in the wind after the foam hood is remove. HAve a look at the MUX box live data. You should read the wind velocity.

When all the connection is done, enable the pitot sensor in the MUX box tab under sensor A1.

The sensor name is 250 km/h pitot speed sensor. 5 Hz sampling rate should be enough for most users ( 5 readings per second ). ote that the 450 km pitot is the same device with the little tab at the bottom of the cube welded. I have not fund this as necessary so far. My pitot was able to record speeds as high as 300 km/h without problem.

Once this is done you should see some live data on the right column. It shows in meters per second. The voice output can be configured in mph though. So no panic here...

Now you could test the system by using a compressor and gently send air into the front of the tube at a distance of 1". You should see the live speed increase a bit.

Then the speed output can be configured in the voice output tab to broadcat MUX box, A1 speed, in mph. However, at this stage of the software version, the warnings are still programmed in meters per second. So if you want to be warned of a low speed of 50 mph, you will need to set it as 27 m/s. However the voice warning will say " caution, MOX box speed fifty miles per hour ".

The 125c temperature sensor:

It is a tiny device that can plug on any analog input  of the MUX box ( A1 to A4 ). Once you have plugged the device and installed it in the fuselage, you can configure the MOX box tab. Here is an example where I set up the temperature sensor on A2.

Then select some sample rate to enable the sensor:

Using a this sensor can be useful to monitor a fuselage temperature at the back of the turbine. However you cannot use it as an EGT sensor as the max reading is 125c. There is a specific device to get EGT readings.

The benefits of the pitot tube over the remote GPS device is twofold. First of all you will have a continuous reading of your speed. With the remote GPS device, the speed will only read when the sensor is looking at the sky and has acquired the satellites. Then the pitot tube will give you an air speed whereas the GPS device will give you a ground speed.

Here is an example of a flight with the pitot tube speed. It is the red curve on the bottom window.

If you want to monitor your approach speed at 1,3 vs and get the system to give you a caution when you reach this speed, I would highly recommend the use of the pitot tube. This is very useful for heavily loaded scale jets. It will enable you to nail your landings every time.

Below is an example of a stall conducted at landing flaps on the Scorpion Mk2. The stall speed is 12.8 m/s or 46 km/h or 28 mph. The approach speed is 1.3 Vs or 17 m/s, 60 km/m, 38 mph.

Additionally you can use the device to monitor your speed in flight and give you a warning when approaching a stall condition.

I typically setup the voice output for the pitot tube as followed:

Control channel= flaps

1. flaps up: minimum speed caution at 1,3 Vs

2. takeoff flaps: maximum speed caution at Vr

3. landing flaps: minimum speed caution at 1,3 Vs

Where Vs is the stall speed for each flap configuration as established by doing a stall test with the pitot tube logging enabled.

The voice output file should show something like this:

On this example the 3 values of 1.3 Vs have been inserted for the 3 flaps settings. I get a caution callout when I reach this value in all situations.

Written by Olivier Nicolas — September 17, 2013

Weatronic RF link diagnostic tool

Here is a short article on how to proceed to format Gigacontrol to standardize the data and be able to compare it with others.

I have create an online database on my blog that is available here:



You will see hundred of RF link diagnostic files taken in all kinds of situations and configurations and you will be able to compare your setup with other's. PLEASE take a few minutes to post your result s as well. The bigger the database, the better...

Insert the micro SD card in the TX module prior to the flight.

After the flight remove the card from the module and insert it in the SD adapter if required.
Download the data to your computer.

Open GigaControl.
Go to the the Nav View window.

Configure Nav View as follows:

Right panel upper window Rx data ( RSSI1, RSSI2, Frames1, Frames2 ):

Erase all the data on the right panel.
Hit the + button and select the following:
"receiver", then RSSI 1rx, then RSSI 2rx, then frame rx1, then frame rx2.

Right panel lower window Tx data ( RSSI1, RSSI2, Frames1, Frames2 ):

Hit the + button and select " diagram below".
Select again the + button and the following:
"transmitter" then RSSI 1tx, then RSSI 2tx, then frame tx1, then frame tx2.

Left panel alfa numeric values and error codes:

Right click on the title box and select "hide all columns"

Then right click again on the title bar and select "receiver" then Frame rx 1, then Frame rx 2, then status rx ( optionally Failsafe ).
Do the same thing with "transmitter" then frame tx 1, frame tx 2, then status tx

You should end up with the following display:

You can now load the nav file by hitting the "open" button and selecting the file target.
The data log will open automatically.
Center the graph to the flight zone ( you will recognize it since the RSSI start to drop when the plane goes away from you ) and zoom it to get rid of the post and pre flight crap.
Select the wrench button on the right panel and select "Y-axis scaling" then "scale possible values"

This option will enable you to evaluate the values compared to their maximum. It is very important to select this option otherwise the graph will not "talk" to you. The program is configured to show the "visible values" by default.

If you see a zone of the flight that you want to evaluate more precisely, then center it on the dotted line, dragging the horizontal button. Then left click on the dotted line. This will automatically pull the associated line on the left alfa numeric panel and highlight it. Note that these lines are only recorded every second on the tx side with the micro receivers. The big receivers can record at a much higher rate on the rx side ( rx micro sd card ).

In the example below I have zoomed on an event in flight 2 and clicked on the dotted line:

The line at 317s is automatically displayed in the left panel and highlighted. I then just have to read the values...

Note that the RSSI values can fluctuate between -110 dBm and -8 dBm, -8 dBm being the highest value ( best reception ).

There are 100 frames per second of which 45 source frames ( flight orders ) . Anything below 100 means that you have lost some of the frames( like the A,B,L,R data on the Spektrum flight log ).
However, the order frames are more than doubled ( 100 frames transmitted for 45 source frames ). So the RF link is very strong.


The idea here is to use the same data formatting for everyone. Look at your configured Navview screen and fillout the following text that you can copy/past in a new post on the Weatronic RF link quality database thread:


Type of receiver:
Type of Tx:
PCM/PPM mode?
Antennas angle and on what plan ?
Left antenna on the xxx axis, right antenna on the xxx axis ( as seen from the front )?

Data analysis for the flight:

Lowest RSSI 1 rx:
Lowest RSSI 2 rx:
Lowest frame rx1:
Lowest frame rx2:

Average RSSI rx values:
Failsafe ?
losses of feedback communication ( 136/168 events ) for a total of x seconds ?

Lowest RSSI 1 tx:
Lowest RSSI 2 tx:
Lowest frame tx1:
Lowest frame tx2:

Average RSSI tx values:

Here is an example taken from my early flight tests two years ago:

Micro 12 receiver on JR 10x. PPM mode. World (besides France).
Antennas at 90 degrees on the horizontal plan.
Left antenna on the pitch axis, right antenna on the roll axis ( as seen from the front )

And the data analysis for the flight:

Lowest RSSI 1 rx: -85,5 dBm
Lowest RSSI 2 rx: -84,5 dBm
Lowest frame rx1: 20
Lowest frame rx2: 21

Average RSSI rx values: -70 dBm
No failsafe
4 losses of feedback communication ( 136/168 events ) for a total of 7 seconds

Lowest RSSI 1 tx: -99,5 dBm
Lowest RSSI 2 tx: -92 dBm
Lowest frame tx1: 9
Lowest frame tx2: 9

Average RSSI tx values: -87 dBm

This will make it very easy for every one to compare the results and will give a massive feedback to all the users.
Thank you very much in advance for contributing.

The error codes are shown on the left window for both the Tx and the Rx.
136/168 means loss of feedback link for the Rx/Tx with no loss of order transmission.

Written by Olivier Nicolas — September 05, 2013

Weatronic system advanced procedures

0.    Introduction


Weatronic have released a revolutionary range of 2.4 Ghz modules and receivers a couple of years ago.

I consider this equipment as revolutionary because they did set a new standard for the industry in terms of functionality and redundancy.

Although some radio makers did reach the technology level offered by the Weatronic system, no one has been able to beat the feature to price ratio that they are offering.

The Weatronic 12-22R gyro III GPS is still unmatched in terms of functionality and price to this date.

I will not go back to a complete description of all the functions available since my friend David Gladwin has done it excellently many times in RCJI.


1.    Why this article ?


Weatronic systems offer so much functionality that I realized that most of the users were either using the system partly wrongly or were using only a few of the advanced functions.

So this article is not a product review. It is aimed at all Weatronic users who want to understanding and using all the functions of their systems and become power users. On that matter it can be considered as a power user manual.

It represents the sum of all the users experience as well as my own one. I have accumulated a very significant amount of data through the RCU Weatronic diagnostic tool thread available here:


On that matter I would like to thank again my modeler friends who sent their results to me and gave me so much interesting feedback to work on.

I was able to write this article thanks to you David, Harry, Jean-Fi, Stephane, Carsten, Sebastien, JPZ, Oistein, Rob, Stripe, Sid, Stanislas, Mark and all the others I am forgetting…

2.    Setting up the system


2.0.         Before starting: firmware update


The Weatronic team is quite reactive to customer’s feedback. They do take into account the customers and beta testers comments and improve the products on a regular basis by releasing new firmware. So it is quite important to keep your devices up to date by uploading the latest firmware.


Bare in mind that some firmware upgrades are not downwards compatible. This means that if you choose to upgrade your system, you will have to upgrade ALL the components. This can take a certain amount of time. Also note that version 2.63 does reset the receiver to default, thus erasing all servo setup and modulation/alarm specifics. So make sure that you have saved the configuration on your PC before going the upgrade way. Also make sure that you disconnect all the servos that could block, before switching your receiver ON again. It will take a few seconds to do a full rebind after the firmware update and load the saved model again. During this time, you might have a servo binding against its full stop position or against each other in case of parallel setup if you are not careful.


The firmware update procedure is explained in a separate document available in the Weatronic folder of your computer ( typically c:/ Program files/ Weatronic/ additional documents/ ) or on Weatronic web site:




There are two update philosophies on the Weatronic devices: direct card reading or USB module update.


2.0.1.   Direct card reading firmware update


The devices with a memory slot are upgradable through a direct reading of the firmware from a card. This is the case for the antenna module and the big 12-22 receivers.

The card reading method is quite easy except that it is sensitive to card formatting specifics. Format the card with a good reading device and use FAT 32. I found out that bad cards/ bad card contacts during the formatting and firmware transfer from the PC tot the card could block the firmware upgrade process.

The usual failures of the update are due to bad card quality, wrong formatting protocol, bad reader used for transferring the file, or wrong file used.


2.0.2.   USB firmware update


The devices without a memory slot will need to be upgraded by plugging a USB updater module from your PC to the USB port of the device. This is the case for the micro, clever and smart series.

You will need to buy the specific update module for this task. The update procedure is well detailed in the manual cited above. One  critical thing: the power up sequence must be strictly followed.

It is absolutely vital for the success of the update procedure that you follow this sequence:

Receiver OFF

Load the program via Gigaupdate

Plug the update module

When the window ”connecting to target” appears, switch the receiver ON.

Then the update sequence will start.

If the receiver is ON while the gigaupdate program is started, the update procedure will fail.


2.1.         Transmitter module description and considerations

2.1.1.   Placing the module in the radio slot and proper connection

The transmitter module is only here to collect the transmitter signal in numerical form and transfer it to the antenna module. It only processes low power electrical signals. The antenna module has the duty to transfer these data to high power through the air information.

It is essential that the data stream is transmitted correctly to the antenna module. If not, the module would only transmit what is available to it without detecting the errors ( crap in, crap out effect). On that matter, make sure that you have inserted the transmitter module in the transmitter slot correctly and that the contacts are perfect on the module plug.

2.1.2.   Placing the patch cable

Similarly, make sure that the patch cable that connects the transmitter module to the antenna module is inserted correctly with perfect contacts. Make sure that you have the new off white color cable and not the older black round cable that could develop intermittent contacts.

Make sure that the cable routes correctly to the module with no tension or possibility to get it pulled from outside interaction.

The early 2.4 Weatronic sets had a black patch cable. This one is prone to developing bad contacts with time. If you have one of these, get it changed by Weatronic to the new tan white patch cable.

Change the patch cable at the end of every flight season to avoid developping false contacts. It is only a few dollars but will garanty perfect operations all the time.

2.1.3.   Description of the data stream from the radio to the module and antenna properties.

The data stream from the radio to the antenna module is collected from the radio module, carried by the patch cable and processed in the antenna module. The type of data is dependent of the modulation chosen from the radio. Although various PCM and PPM schemes can be chosen, only channel orders are sent to the antenna module. This module will then process the channel orders and send them to the receiver using Weatronic’s own transmission protocol.

So choosing between the different transmission modes in the transmitter only matters in terms of number of channel available and number of source frames. PCM protocols usually use less source frames. For example the standard JR PCM protocol transmits 25 frames per second on 10 channels, whereas the PPM protocol transmits 50 frames per second on 9 channels. So that is twice faster, but you’d lose one channel. The Weatronic system transmits 100 frames per second on two independent RF links. So choosing a JR PPM mode will make the Weatronic system transmit each source frame from the Tx twice in a row till the next new frame comes from the Tx. Choosing the standard JR PCM mode will make the system transmit each Tx source frame 4 times in a row.

The description of the modulations modes and optimal setup for your radio is explained in a separate document available on the Weatronic download site in German:



To access the source frame transmitted information, you’ll have to look at the NavView tab of Gigacontrol, in the live data window.



The transmitter module antennas are placed along the edges of the case. These antennas are very sensitive to body masking. This is because of the short wavelength and the fact that this modulation is very well absorbed by organic tissues. So do not place your hand along the antenna module while flying and do not allow anyone to pass in front of you.


The receiver wire antennas have a standard cardioids reception diagram. This means that the sensitivity field looks like an apple centered along the antenna wire, with the least sensitivity along the wire axis. This is the reason why the manufacturer recommends placing the antennas 90 degrees of each other: to avoid having the two low axis of the two antennas coinciding and “looking” at the transmitter. The hemispheric diagram of the patch antennas does not create this problem.

Also bare in mind that the wave of a 2.4Ghz signal is only a few centimeter long. So large conductive objects like the thrust pipe or the engine may mask an antenna. I found out however that the receiver is doing quite well with carbon fiber structures.

2.1.4.   The antenna module LEDs description.


The antenna module has a series of 3 LEDs set on the long side of the case. It is important to install the case so that the LEDs are visible from the top.

It is also equally important to understand the blinking functions and meanings of these LEDs.

This was described in the original 2.4 user manual published in August 2009. However this description was not complete. A new separate document has been issued and is available in English language here:



Note that the red LED blinking will coincide with a beep emitted from the headset port. The beeping scheme follows the red LED scheme with a distinction between the receiver and the transmitter that is quite important to understand. A high pitch beep is emitted for a receiver failure, whereas a low pitch beeper will indicate a transmitter failure.

For example, if you ear two high pitch beeps, this indicates a receiver battery threshold reached, whereas is you ear two low pitch beeps, this would indicate a transmitter battery threshold reached.

For people having uploaded the English voice file into the DV4 antenna module with firmware 2.63, the meaning of the beep will be enonciated in plain language.


2.2.         Choosing and setting up the batteries


The micro and smart receivers: they use direct current from the batteries, without any built in regulators.

The 12-22R Gizmo unit: it has 4 power bus regulators that are distributed by row. Regulator 1 distributes to servo 1 -8, regulator 2 to servo 9-18 etc...

A line protection function monitors the resistance downstream the regulator. If it drops suddenly ( shortcut ) the regulator and supply row shuts down to protect the other devices.

The typical voltage regulator drop is 0,6V. This means that if a battery drops below 6,5V while the regulator is trying to maintain 5,9V, the later will be disconnected and the second battery will be used.

A battery test routine is being done every time the Gizmo receiver is switched ON. It is user configurable. In the receiver configuration tab and set to trigger by default at 0,5V drop.

Each time the Gizmo receiver is powered up, a 7 amp load is applied to each battery for 25 ms. If the battery voltage drops during that time below the programmed value, the system will issue a battery warning.



On the micro series, the servo line is limited to 5A. However there is one trick that doubles this capacity. This is due to the Kirschoff's law. If you place one battery line at one end of the servo bank ( plug 1 ) and one battery line at the other end ( battery plug ), you can effectively draw 10 amps on the bank: 5 amps from each side. So I highly recommend this configuration. Plug 1 is usually dedicated to the throttle output. Just Y wire the throttle line with the battery line and you are all set...



2.3.         Placing the receiver

Reading the Rx LED: it is important to place the receiver so that the status LED's can be seen for startup troubleshooting. In the case of the Gizmo units, the switching module have the LED and is easier to place.

The receiver has eight regulators protruding at the bottom of the unit. They must be cooled down properly to avoid a receiver shut-down is case of thermal runaway. I highly recommend making a square hole in the receiver tray at the regulators location. If this is not possible the other option would be to place rubber grommets under the receiver to lift it from the tray by at least 2 mm.


There is no need for flexible receiver installation in jets. Gyro equipped units will benefit from this fact with a more precise operation.

Servo lines requirements: HF ferrite rings are not necessary on the lines, on the receiver side. Good quality twisted cables are recommended as usual. I recommend the use of our MIL spec AWG22 pure silver servo cables with this equipment for the long line and/ or line passing close to the engine or tailpipe.

If the cable lines are long, you might want to put ferrites at the servo side to avoid transmission of EMIs to the servo.

Battery cables requirements: I also recommend the use of our 12AWG MIl spec pure silver cables for connecting the batteries to the receiver, along with our professional grade EMS plugs complying with Multiplex standards.

The idea is to remain coherent with the battery cables coming from the receivers as installed by Weatronic.


Access to the memory card slot:


Keep in mind when installing the receiver that you will need to remove and place the memory card very often. Make sure that you leave enough room around the base of the unit to place/ remove the micro SD card.



2.4.         The switch box (Gizmo)



The switch box is a small plastic unit connected to the receiver by the means of a flat ribbon cable. Its purpose is to provide an easy way to switch the device ON and OFF through a flagged jumper.

It also houses two high intensity LED's that are meant to advise the modeler visually of the status of the system.

Although this system is nice, with the new voice file all the alerts are in plain language, making the identification of the problem very easy.

The switch box is also used to place the Gizmo receiver in binding mode or firmware update mode.


I recommend placing the unit in an easy to access location for obvious reasons. on sport models, placing the unit flush along the fuselage skin is a valid option.

cable length change:

The ribbon cable can be shortened or changed for a much longer one. Different lengths are available in the store if you need to place the unit far away from the receiver. The cable should be cut clean and straight. Make sure that you insert the ribbon cable clamp correctly into the cable: you should see the hooks passing through the ribbon plastic isolation. Also pay a particular attention to the ribbon polarization. A red line is printed on the side of the cable to help you with this.

Removing the plastic housing:

Te switch box plastic housing is quite bulky. It can be removed for those who are a bit tight with room. If you do so, make sure that the back of the switch board is seperated from any carbon fiber plate or conductive component. A shortcut of this board can result in a receiver power down.

LED codes reading: The switch box LED code is explained in a separate document available on line:


LED fault indication philosophy vs Tx module:

The LED blinking sequence on the switch board is different from the one from the Tx antenna module. Make sure that you read the document above at least once to understand the differences.

Switching plugs: braking the strap:

The flagged jumper has got a metallic loop that is retaining the red or blue flag. This loop is actually the conductive part of the jumper. If it brakes , the jumper will become useless. Since you might be tempted to pull the plug from the flag, it might actually brake after a while. This happened to me once and I recommend carrying an extra red flagged jumper in your field box just in case.


2.5.         Plugging your servos: the power banks (Gizmo)

2.5.1.   The servo mapping page


How to read it ?


The servo mapping page is setup as a matrix. The left column displays the channels input, whereas the upper line displays the receiver servo outputs.

Any channel can be attributed to any servo output by clicking on the corresponding square.


Assignment of a servo: usage of colors

I strongly recommend changing the name of the channel inputs and using colors as a backgoround to them. The reason for this is that when you will start mixing channels together, it will be much easier to understan what you are doing as every line of the mixer will have the color of the assiciated channel.


The power bus and voltage regulator distribution:

The Weatronic Dual Receivers are fitted with a high current power system for dealing with modern high current digital servos and consists of 8 separate voltage regulators, all of which are protected against shorting or excess current consumption. Each circuit can draw a maximum of 5 Amps continuous, which means that you can safely draw up to 40 Amps in total providing that the receiver is sufficiently cooled down from below and for short (burst ) periods even higher currents can be drawn.

Each voltage regulator has 3 to 4 servos output hard assigned. The assignment occurs vertically on the power bank. and can be seen directly on the receiver casing.

Voltage regulator 1 is powering servos 1, 9, 17 and 25.

Voltage regulator 2 is powering servos 2, 10, 18 and 26.

Voltage regulator 3 is powering servos 3, 11, 19 and 27.

Voltage regulator 4 is powering servos 4, 12, 20 and 28.

Voltage regulator 5 is powering servos 5, 13, 21 and 29.

Voltage regulator 6 is powering servos 6, 14, 22 and 30.

Voltage regulator 7 is powering servos 7, 15 and 23.

Voltage regulator 8 is powering servos 8, 16 and 24.


It is important to understand this fact in order to balance the power requirement for each voltage regulator. Try to split the big current consumers between the different regulators. Also this will have the added benefits of keeping redundancy if one line shuts down due to a shortcut or excess current consumption.

It is also important to understand that a powerful digital servo binding could result in a temporary voltage regulator shut down. So spreading your important flight controls servos between the different power banks is a must on this receiver.


As a consequence, you will see that every time you assign a channel input to a servo output in Gigacontrol, this will have for effect to blank 3 other servo outputs on the servo mapping grid. These positions will turn pink on the grid. On the screen capture below, assigning channel 1 to servo 1 has for effect to blank positions 9, 17 and 25. In other words, the program tells you that a channel cannot be assigned twice on the same power bank.


2.5.2.   Assigning your servos

Similarily, several considerations must be taken about assigning the servo to different channel/ output combinations.

First of all, you'll need to check the servo torque requirement for your application. That can be computed using the Control Calc sheet available here:


For more details on how to use Control Cal, please refer to my blog here:



Then you will have to check the maximum current draw for the torque required. This is normally given by the manufacturer on the spec sheet of the servo. However I have found out that the information is sometimes difficult to find. For Futaba servos, this is available from the Servo city page.

Otherwise, you can use this graph as a frist approximation where the current is in Ampere and the torque in oz.in:



Servo voltage requirements and strategy:

If you mix high current servos with low current servos, you will need to keep in mind that if a servo bank is set at a certain voltage, all the servos on that bank will operate under the same voltage. For example if you set the voltage regulator 1 at 7.2V, servos 1, 9, 17 and 25 will operate under that voltage.

Servo line length:

The servo line length does not really matter with the Weatronic system. The voltage regulator will meet the demand required by its power bus. That is because the regulator is constantly checking the line resistance and adapts in consequence ( this is the feature that is used to trip off the regulator in case of a short circuit which equate in a sudden drop of the line resistance.

Placement strategy on the power bus:

As a general rule, I'd recommend to place one of each main control surface on a different regulator, then assign other less important servos.


2.6.         Gigacontrol setup.


2.6.1 General philosophy: Tx editing vs Giga Control editing,

Although some transmitters have very advanced mixer and servo curve editing possibilities, Gigacontrol allows you to mix channel entries and servos outputs within the receiver.

This has several advantages. Among some of them the graphic presentation of the servo curve is very precise and easy to read. As well the mixer presentation is most of the times much easier to understand and verify than the Tx one. Also the mixer curve can be modified along 30 points. This is a very rare a powerful function.

2.6.2 Servo mapping tab general considerations:

This window, together with the “NavView” tab forms the heart of the GigaControl software. Within this window a multitude of parameters can be altered which will improve every model’s performance from large scale jets through to gliders. The left hand side of the matrix lists the transmitter’s channels or functions and the software is currently capable of handling 12 channels but this will soon be raised to 16. The top row corresponds to the receiver outputs of which the micro series receivers have 8 to 12 and the 12-22 R series have 22 to 30 outputs.


The standard servo mapping window for the micro 12 receiver. 12 input channels, 12 servo output.


The standard servo mapping window for the Gizmo 12-30 R HV receiver. 12 input channels, 30 servo output.


The background as well as text content and color of each input and output can be changed. This is quite important and extremely useful as soon as you start implementing mixers or using gyros.

To edit the text, text color or background color, simply left click on the field you want to change and select the available options.



In this example, servo 1 was changed to "ECU" with red background and blue text and Channel 1 was changed to "Throttle" with orange background and blue text.

It has the following effect:



I'd recommend to make a sensible use of the colors. Use a family of colors for the flight control and another family for the accessories for example. Each servo output in the family can have a different shade of thhat color. This will help you to immediately recognize what you are doing. Furthermore, I'd recommend you to save a base configuration of the Gigacontrol window when you have finished editing the names and colours. This way, next time you need to create a new model, just upload the base config and you will save a lot of time avoiding to re-create all the allocations.


You can link up to a maximum of 8 receiver outputs to each transmitter channel or function which will allow you to drive up to 8 servos or other devices simultaneously, almost as if you had an 8 way ‘V’ cable connected to the receiver output but with the exception that each servo can be programmed independently.

To assign an output to a function, simply click onto the relevant field with the left mouse button which will turn the field to a green background.



To delete an allocation simply click onto the green field and after acknowledging the following warning message the selection will be cleared.


The field that displays in green can be configured by right clicking on it. Let's do it for the first field re-labeled Throttle/ ECU.

A configuration window will open as followed:



This is where all of the settings for each servo output can be adjusted relative to the control input. Any setting changed must be stored before they become effective.

Note that the servo output index has turned in red color and the channel input index in orange color.


To save your settings, click the ‘Store’ button which is located in the lower right hand corner. If you do not wish to save the changes, click ‘Abort’.

Lets first look at the window located in the top left hand corner:


In this example, as previously explained, servo 1 is now called ECU and is a single servo not expanded through any multi box option. Pulse rate can be changed from 3 ms ( very fast professional servos ) to 30 ms ( slow analog servos ).

The servo failsafe has not been attributed yet.

The servo has not been slowed down. It is important to understand that the slowing option will affect the output ( concerned servo ) not the input ( concerned channel ). If you want to implement a door sequencer function ( to be detailed further down ) the servo slow option here will have no effect on the sequencing and should therefore not be used for this function.


To the right of the servo configuration window, you will see the gyro setup area. Gyro setup will be discussed further down in part 7.



Then you have the servo synchronization window that will be discussed in part 7 as well.


2.6.3. Configuring servo curves


Use the right mouse button to select the output which you wish to configure to access the curve window The servo curve is represented in the diagram shown in the lower part of the window which is pictured above. Initially the servo curve will be a straight line, shown below as an orange line, as if the transmitter function has been highlighted with a background colour, it will be displayed in that colour ( orange here ).



The orange index (2) below the servo curve represents the transmitter channel position and will follow the stick, switch or slider as it is moved. The red index (3) to the left of the servo curve represents the actual servo position as it moves related to the curve shape. To ease the identification of which function/servo is being viewed, both of these bars will be in the same colour as the backgorund colour that was set in the servo mapping screen, as illustrated above. If no colour has been set, the bars will default to green.


To the right of the servo curve there are 5 buttons, labelled, for example, “Move curve“, Invert curve channel and servo, reset curve, assume failsafe, maximum, minimum. They will help in adjusting the servo curve..


“Move curve“:

Under normal circumstances the servo travel will be a linear function of the channel travel with the neutral point at the centre.

The white area represents 100% of servo throw and the upper and lower red areas are the values which a servo can theoretically travel t,o up to 200%.

Once you have activated the“Move curve“ button using the mouse the whole curve can be raised or lowered by clicking on one of the red points, holding down the mouse button and moving the curve (line) upwards or downwards.

The same effect can be achieved by clicking onto the curve (line) and by using the keyboard’s arrow keys to move it. Using the arrows will achieve a much thinner result and you will need at least 5 clicks of the same arrow to see the curve moving a tiny bit.


In moving the curve you can adjust the middle (neutral) point for each servo.

This option will be partially useful to accurately set-up any function which is driven by two or more separate servos, for example, flaps, airbrakes ailerons or elevators. Servo neutral (middle) position adjusted by moving the curve.

HOWEVER! Every servo is different in as much as how far it can rotate before it will damage itself. IMPORTANT! Always be careful when adjusting the servo curve, in particular when the values are within the red fields. Connect a servo to the receiver when adjusting the curve and always observe the manufacturers.


“Invert curve (channel)“:

By clicking on this button the transmitter function will be reversed, i.e. left stick will produce a right stick reaction from the receiver and the function will be reversed.


“Invert curve (servo)”:

By clicking this button the direction of rotation of the servo will be reversed, and each servo can have its direction changed independently.This function is useful when more than one servo is grouped together to ensure that the linkages can be fitted to the correct side of the servo.


“Reset curve“:

This button will return the curve to the default settings.


“Channel name, minimum, maximum“:


These three values can be left clicked  and will have the effect of highlighting the associated curve and show their input/ output value for a given channel position in the upper "channel value/ servo value" box.

Editing "minimum and maximum" is important. This sets the hard stop point of the servo to never exceed. It is especially relevent when using gyros or mixers as these functions could drive the output past the servos limit'

Let's have a look at an example.


Here I have clicked on the "minimum" field (1). This has for effect to turn the lower horizontal hard limit line in bold green ( 2) I can now drag it to the value I want with the mouse. This value shows in the grey "minimum" window (3). Now the lower hard limit for this servo is set at -111%.



The default settings for the servo curves allocates them 5 points which are indicated by the large dots .




Servo curve adjustment points:

The green dots are the points at which the servo curve can be altered by simply clicking onto them (left mouse button) which will cause them to turn red (active) and they can then be moved by dragging them up or down. You can also use the arrow keys to move them ¥£¢¤. In addition to the 5 fixed points, each servo curve for the Master servo of a group or a single servo can have up to 31 adjustment points added to them.


To add an adjustment point, use the right mouse button to click onto one of the smaller dark dots which will ‘active’ it, it will then become an adjustment point which can be tailored as explained in the paragraph above. If you want to reverse the selection, use the right mouse button once again to click onto the Point and it will


revert to a small dark dot.


Each ‘active ‘point can now be moved as required which will allow you to tailor the curve to create, for example, an exponential function to ‘fine tune’ the control response of your model as illustrated below.



Example of a servo curve which will create an exponential movement of the servo


A servo curve which has been tailored to create differential moment which be useful if, for example, you want your ailerons to have move movement up than down to prevent adverse drag.


2.6.4. Configuring the failsafe

The Weatronic system will ignore any Failsafe signals transmitted by your transmitter, This is because we have incorporated our own user-friendly multi-function Failsafe system.


Firstly, set the Failsafe time out value which can be programmed between 100 milliseconds and 1 second. This is done in the receiver configuration tab, under Failsafe timeout window,


In the unlikely event that the receiver looses the transmitter signal, the servos will move to a pre-determined ‘Failsafe’ position or, if no Failsafe position has been set, they will ‘Hold’ where they are.

If no Failsafe position has been set, the system will default to the factory setting. The factory setting is the neutral or middle point for all servos and functions.

Weatronic differentiates between ‘Channel Failsafe’ and ‘Servo Failsafe’. The Channel Failsafe function will apply to all servos linked to that function and Servo Failsafe allows you to programing individual servos allocated to a channel singularly.


Channel Failsafe

You can decide whether you want the servos to hold the position where the last known good signal was received (‘Hold’), or to move to a pre-determined point, for example, tick over for the engine (‘Failsafe’).


To choose one of these options the servo mapping window has to be opened. Within this window you will see a field labelled Failsafe type on the right hand side. In this column you'll find boxes for each channel. Each box should be set to ‘F’ for ‘Failsafe’ or ‘H’for ‘Hold’ by clicking it with the left mouse button.



If you have selected ‘F’ for any function click onto that function with the right mouse to open the Configure servo window. A green dot is visible in the upper bar and by clicking onto this dot with the left mouse button and moving it to the left or right the Failsafe position can be set for that channel . The dot will turn to red to indicate that it has been set. The position of the dot will be displayed in the box to the right of the field both as a percentage and in steps (max.+/- 2048).



The red dot in the upper field shows a Failsafe position of – 90%.

If ‘H’ for hold has been selected, the green dot will not appear as the last known good signal position will automatically be held.


Servo Failsafe

If a group of servos or devices have been allocated to one channel (ECu, 2 and 3, have been linked to channel 1.


By left clicking the field labelled ‘Servo failsafe’ a tick will appear in the box and a red dot can be seen in the right hand column (labelled Failsafe position servo). The desired Failsafe position can now be set by dragging the red dot. This procedure can be applied to all of the remaining servos.


2.6.5. Other basic functions


Copying servo settings

Once you have found the correct setting for one servo, these values can be copied to another servo by using the ‘Copy servo settings’ function. To access this function click on the button located at the bottom of the ‘Servo mapping’ window. In the upper field you can select the servo setting which you want to copy and in the lower field is a list of the servos which the settings can be copied to. Once you have selected the ‘from’ and the ‘to’ servos in the relevant boxes, click ‘OK’ to copy the settings.


Setting the servo voltage ( Gizmo )

The Gizmo series have the ability to let you set the regulator voltage for each servo bank.

To access this function, click on the box situated at the bottom of the servo mapping window and called " servo voltage ".



A choice of two values will be available for each servo bank Either 4.8 V/ 5.9 V or 5.9 V/ 7.4 V depending of your receiver type. When you select a value for a given bank, all the servos in the bank will run on that value. Make sure that all the servo are compatible in case of selecting a voltage of 7,4V for the HV versions.


Fixed values

If you require a servo or function to hold a set position and not to move proportionally with the transmitter function (i.e. for Gyro sensitivity) ‘Fixed value’ must be selected in the ‘Servo mapping’window. This option is at the bottom of the window and if it is click the field will turn to green.



If you right clic the field, a window will open which is similar to the servo configuration window. You can then drag the flat line within this window to set you fixed value.


Saving your servo setting


Every time you alter the servo mapping page, you must store the new setup before you exit te window. In orer to do so, click on the "store" button at the bottom of the page.


Saving your model setting


Similarly, every time you have made changes to your model, I would recommend you to save a new version of the program with the current date emedded into the name. This will allow you to keep a trace of the model setup and revert to a previous setting if necessary.




3.    Testing the system

3.1.     First functional test via GigaControl

The benefits of using GigaControl with live data

The transmitter page ( Tx configuration tab )

The receiver page ( Rx configuration tab )

The Nav View page and live data function

Checking the servos and lines: the monitor page


3.2.     Electrical tests and line isolation ( load shedding ) function

Torture test

Endurance test

Temperature limits, heat sink and temperature warning

3.3.     Workshop range test

Benefits of a workshop test ?

Benefits of using the Nav View live data rather than the LQI data

Setting up your warning limits

Range test function and prolonging

Antenna diagram and redundancy

Transcription of the antenna diagram

3.3.     Airfield apron range test

Procedure, live view vs LQI

Validation for flight

3.3.     Flight range test

Considerations: short flight, short distance, beeps monitoring, live data monitoring by helper.

Post flight data analysis for the first flights with the help of the GPS.

Data validation

4.    Live flight and performance monitoring

Interest of live data monitoring.


4.1.     Setting up the warnings

Editing the receiver and transmitter configuration pages.


4.2.     Monitoring the system: LED vs audio

4.2.1.  LED

Tx LED function

LED blinking codes

4.2.2.  Audio

Audio file philosophy: beeps vs voice

Beep codes: high pitch vs low pitch

Beep codes training: range test

The voice file installation

The sensors page

Switch assignment in V2.63: speed mode, altitude mode, position mode, quiet mode

Keep it simple

4.3.     Live data monitoring in Nav View


Usage by spotter

Practical case: the maiden and first test flights

5.    Data logging and post flight processing


Interest of post flight data analysis and logging on the long term

Flight log example


5.1.     Memory card recording: formatting

5.2.     What slot to use in case of a 12-22R

5.3.     How to transfer the file and naming

5.4.     Reading the file in Giga Control

5.5.     Data analysis

5.5.1.  Configuring the windows in NavView

5.5.2.  Isolating the flight data

5.5.3.  Frame rates vs RSSI

5.5.4.  Rx status codes

5.5.5.  Event analyzing

5.5.6.  Loss of Tx datalink


6.    System monitoring

Initial RSSI logging and evolution monitoring

Batteries monitoring

Servos monitoring: current consumption

7.    Advanced programming


7.1.     Using the Gyros


The gyros used by Weatronic are very decent units that are fast and sensitive enough for most uses, especially with jets models.


7.1.1.  Assigning the gyros per axis

It is important to understand that the gyros have a fixed direction along the receiver casing. The Gizmo was designed to be put into relatively narrow fuselages along its length. As a result , the direction along the length is predefined as gyro 1


If your receiver is placed so that its length is along the fuselage axis, then gyro 1 would be assigned to the roll axis, gyro 2 to the pitch axis and gyro 3 to the yaw axis.

On a standard model with this receiver position, gyro 1 would be programmed on 1 or 2 aileron servos ( 1 servo is usually enough ), gyro 2 on both elevator servos and gyro 3 on the nose wheel steering ( if stabilization is required during taxi ) or rudder ( if stabilization is required in flight ).


On a delta wing model like the Rafale or Mirage 2000 with the same receiver position, both tailerons would have both gyros 1 and 2 assigned. Gyro 1 would take care of the roll damping and gyro 2 of the pitch damping. Gyros actions would be reversed for taileron 1 and taileron 2.


Here is an example of gyro assignement on a F-18F

Select the servo output you want to assign ( here elevator 1 )

1, On the servo curve wiindow, select gyro 2 ( choice of no gyro, gyro 1, gyro 2, gyro 3, external inputs )

2, Select normal operations ( coice of normal operations, heading lock, normal/ hdg lock )

3, Select invert direction or not and Alt. sensitivity ( altered ) then select fixed value ( choice of fixed value or a specific channel to set the value )

  1.  select sens gyro 1. The horizontal green gyro line will turn bold.
  2. Drag it to match the value you want, The value will show in the grey "Sens gyro 1" window.



7.1.2.  Verifying the correct way of action


Once the gyro has been activated, it is EXTREMELY important to verify the correct way of action of the gyro. For the pitch axis, place the model on the ground on its wheels. Grab the tail and rapidly pitch the model up. You should the the elevator moving down to create a pitch down effect. If not, invert the gyro direction as shown above and try again.

For the roll axis have two people hold the plane from the nose and tail and bank the model towrds one direction. The ailerons should counter that roll effect. If not invert the gyro directions and try again.

7.1.3.  Adjusting the gain: fixed vs variable


The gyros gain is a very important parameter. This will influence the stability of the model. If the gain is set very high, the model will be very stable but the maneuverabilty will decrease. Each time a servo is moving to get the plane to maneuver, the gyro will fight this action and try to keep the model straight. Furthermore a very high gain can make the gyro create a servo oscillation that can produce flutter. Here is an example shown on this in-flight video footage.

Have a look at the ailerons on high speed passes. The gain was clearly too high on that flight.


F-18F and B300F from Oli Ni on Vimeo.


 Therefore it is important to be able to change the gyro gain on the first test flights ( ie to assign it to a switch ) and later on to have a dynamic gain control ( the gain reduces asa the flight control deflects ).

I will explain below how to set his up.


7.1.4. Adjusting the gain: dynamic gain


The idea here is to change the sensitivity of the gyro thanks to another channel. You could, for example, assign the gyro gain to a rotating knob and optimize the gain in flight for a given configuration.

To do so, just change the value in the window showing "fixed rate" by any channel you want ( 1 in the example below).

The next step is to get the gain to vary according to the same channel value. What is the benefits of this? Well you can get a specific damping value for each deflection of the channel. For example, you could get a higher damping value around the servo neutral position to get a high stability when not touching the controls, and then a lower damping value when moving the controls to increase maneuverability.

Here is how to proceed. In the example below, I have assigned the altered sensitivity to the elevator channel (1), Now the gyro flat curve has changed to a diagonal paralleling the elevator curve. I can now move the curve by selecting "gyro sens 1" (2) then "move curve" (3) and dragging the curve as i want (4). In this example, when the elevator channel is at -100%, the gyro gain is at -140%.

When the channel value is at +100%, the gyro gain is at +51%.

The next step is now to make the gyro sensitive around neutral and non sensitive when the channel is moved.

For this, we will need to drag the left side of the curve to a low value by hitting the "move curve" button (1), then dragging that side to -150% (2). Then deselect the "move curve" option (1) and modify the curved points by dragging them with a left mouse click. In the example below, I have increased the top gain in neutral to +45%, +50%, +45% (3) and then returned the curve to -150% (4)



7.1.5.  Flight test validation

Increase the gain step by step starting from -25%

Up to +70%: manageable

7.1.6.  Preflight procedure

Verify the gyro function and correction way before each flight day.

The variable gain philosophy: safer

7.2.     Using the mixers

Radio mixers vs receiver mixers

Assignment: using colours

Fixed value adding

Variable mixer



7.3.     Synchronizing several servos on the same control


7.4.     The sequencer function


Written by Olivier Nicolas — August 18, 2013

Welcome to Ultimate Jets.

We are the one and only USA based turbine powered UAV and hobby models manufacturer. Ultimate jets offers some of the best engines, kits, and accessories to the Industry. ................................................... We offer in-house design and manufacture services for military and hobby companies. Our expertise extends from aero dynamics design to carbon fiber aerostructures manufacture and 5 axis CNC milling and turning. ................................................... We are the USA distributors for Behotec, BF-Turbines, Mibo and Aviation Design and provide in-house support and service for these products. ................................................... We also are dealers for the following brands: Jets-Munt, Permagrit, Ultratool, Cotronics, Techflex and many other aerospace industry suppliers. ................................................... We finally house a unique technical blog that you will find below, providing industry reference articles. Please feel free to browse through these pages. Enjoy... Barry, Woody, Shaun and Oli.