After months of positive tests flying with different radios, protocols and receivers i can say that the goal of the project is reached.
No further development will be done in order to keep this level of security and service.
I decided not to share the source becouse of the risks that you can face modifying the code.
Anyway anyone can develop the same code studying the multiprotocol project https://github.com/pascallanger/DIY-Multiprotocol-TX-Module
Hex file SHA256 9d87e2f495c9ef474c45266540afff5d8dff5106e50e043381523d666f7a5b58
Can be checked at https://emn178.github.io/online-tools/sha256_checksum.html
Radios tested: Futaba T9, T14SG, T14MZ
Serial Multiprotocol interface for Futaba or every transmitter with PPM interface ( via trainer port ).
Goal: Give to all Futaba radios and more in general to all PPM capable radios, the possibility to use the multiprotocol module iRangeX IRX4 Plus or iRangeX IRX4 Lite via serial connection.
Legal aspects:
In EU is legal to control remote aircrafts only if:
-Use a ground control station (aka transmitter) that is EU Certified.
*-Note that transmitters that have installed open source firmware loose conformity and are not legal in EU.
-Use a RX that works on a certified protocol in EU in the band of 2.4 Ghz only.
For example: Spektrum DSM 1 - No more available but certified in EU - Legal to use. Spektrum DSM 2 - Never certified in EU - NOT Legal to use. Spektrum DSM X - Still Available and certified in EU - Legal to use.
Adavantages:
1: Use your own trusted transmitter.
2: Use transmitter that has proprietary firmware, stable and solid( e.g. Futaba, Spektrum, Jr ... )
3: Avoid "Loss of conformity" (EU law 2019/947) of your trasmitter installing open source firmwares not certified by the constructor.
4: Save money, no need to buy other trasmitters.
5: Using the multiprotocol module iRangeX IRX4 Plus in serial mode is far more simpler and safer then using PPM mode, no need to select protocol via the knob and bank of memory. Also avoid the risk to destroy contacts of the knob.
USAGE
After turning on the transmitter, the last used protocol is prompted.
After 10 seconds the prompted protocol is activated unless ailerons stick is moved.
Moving ailerons stick you can change the protocol to be activated(see pictures below).
Once done you can move down elevator stick or wait 10 seconds to activate the selected protocol.
See the picture above with radio in flight mode.
Important: For security reasons once protocol is activated (Flight Mode), it cannot be changed anymore. Need to recycle power.
Pay attention that is used channel 1 for ailerons and channel 2 for elevators (AETR). If you use other mapping channels move sticks accordingly for channels 1 and 2.
Channel mapping affects only protocol selection while the real channel mapping for your RX is controlled by the firmware version loaded on the IRANGEX
BINDING procedure
After turning on the transmitter, move elevator stick UP to activate binding procedure as shown on the display.
You have 10 seconds to put receiver on bind mode if not done before. After 10 seconds system will return to protocol selection.
Power consumption
With Futaba T14SG power consumption with internal module is 152mah.
With this system and iRangeX IRX4 Plus 2.4G power consumption is almost identical, 153mah.
So no issue with battery.
Supported protocols
All the protocols of the IRANGEX are supported.
With scdcard a file named PROT.TXT is scanned to let browse supported protocols.
User can choose protocols to use instead of browsing more then 100 protocols.
Here is an example of PROT.TXT file(if sdcard is not present, system defaults to the protocols as shown in the example below):
"FRSKY D ",003,00,252 " KDS ",024,00,000 " CORONA ",037,16,254 "AFHDS2A ",028,17,000 " DSMX ",006,48,000 "FRSKY R ",015,00,252
fixed record lenght of 23 bytes 21 of data and CRLF
Syntax: protocol name, protocol number, RxNum | Power | Sub protocol, fine tuning
BOM
1 x Arduino nano
1 x Oled display SH1106 or SSD1306
1 x iRangeX IRX4 Plus or iRangeX IRX4 Lite 2.4G CC2500 NRF24L01 A7105 CYRF6936 4 IN 1
1 x Sdcard module (Optional)
Binary to upload to arduino nano (find instructions online).
The binary works with all combinations of components listed before.
Connection diagrams
Oled Display _______________ Nano SH1106 SSD1306
A4 SDA SDA
A5 SCL SCL/SCK
5V VCC VCC
GND GND GND
POWER _______________ NANO TX VIN 8.4+ ( Tested with Lipo 2S/3S ) GND GND
PPM in from TX to nano _______________ NANO TX D2 PPM signal out
Nano Serial to Multiprotocol module _______________ NANO MPM TX1 Serial in VIN +BAT GND -GND
Irx4 back view. MPM IRX4 Plus Pinout _______________ ___________ | | | | | | | | | x| Serial In | x| | x| +Bat | x| -GND |________x| MPM IRX4 Lite Pinout _______________ ___________________ | | | | | | | | | o o o o o o o o | | - + S | | | | | |_________________|
Thanks to:
https://downloads.multi-module.org/?irangex
https://github.com/pascallanger/DIY-Multiprotocol-TX-Module
