- Protocol and type: many main protocols have variants
- RX Num: number your different RXs and make sure only one model will react to the commands
- Power: High or low, enables to lower the power setting of your TX (indoor for example).
- Option: -127..+127 allowing to set specific protocol options. Like for Hubsan to set the video frequency.
- Bind: bind a RX/model
- Autobind: Yes or No. At the model selection (or power applied to the TX) a bind sequence will be initiated
- Range: test range by setting the transmission power to the lowest value
Note:
- there is 2 versions of serial protocol either 8 or 16 channels. 16 channels is the latest version. Make sure to use the right version based on your version of er9x/ersky9x.
###Telemetry
Telemetry is available for er9x and ersky9x TX.
There are only 2 protocols so far supporting telemetry: Hubsan and Frsky.
To enable telemetry on Turnigy 9X or 9XR you need to modify your TX following one of the Frsky mod like this [one](http://blog.oscarliang.net/turnigy-9x-advance-mod/).
- [A7105](http://www.banggood.com/XL7105-D03-A7105-Modification-Module-Support-Deviation-Galee-Flysky-p-922603.html) for Flysky, Hubsan
- [CC2500](http://www.banggood.com/CC2500-PA-LNA-Romote-Wireless-Module-CC2500-SI4432-NRF24L01-p-922595.html) for Frsky
- [CYRF6936](http://www.ehirobo.com/walkera-wk-devo-s-mod-devo-8-or-12-to-devo-8s-or-12s-upgrade-module.html) for DSM2, DSMX, DEVO, Walkera
- [NRF24L01](http://www.banggood.com/2_4G-NRF24L01-PA-LNA-Wireless-Module-1632mm-Without-Antenna-p-922601.html) for Hisky, V2x2, CX-10, SYMAX and plenty other protocols
RF modules can be installed for protocols need only. Example: if you only need the Hubsan protocol then install only a A7105 on your board.
You also need some [antennas](http://www.banggood.com/2_4GHz-3dBi-RP-SMA-Connector-Booster-Wireless-Antenna-Modem-Router-p-979407.html) and [cables](http://www.banggood.com/10cm-PCI-UFL-IPX-to-RPSMA-Female-Jack-Pigtail-Cable-p-924933.html).
###Microcontroller
The main program is running on a ATMEGA328 running @16MHz and 3.3V.
An [Arduino pro mini](http://www.banggood.com/Wholesale-New-Ver-Pro-Mini-ATMEGA328-328p-5V-16MHz-Arduino-Compatible-Nano-Size-p-68534.html) can be used to build your Multimodule:
Multiprotocol.ino header can be modified to compile with/without some protocols, change protocols/sub_protocols associated with dial for PPM input, different channel orders, different channels timing, 8 or 16 channels serial protocol, Telemetry or not, ...
It is recommended to use an external programmer like [USBASP](http://www.banggood.com/USBASP-USBISP-3_3-5V-AVR-Downloader-Programmer-With-ATMEGA8-ATMEGA128-p-934425.html) to upload the code in the Atmega328. The programmer should be set to 3.3V or nothing to not supply any over voltage to the multimodule and avoid any damages.
From the Arduino environment, you can use this shortcut to compile and upload to the module: Skecth->Upload Using Programmer (Ctrl+Maj+U)
Make sure to follow the following procedure: press the bind button, apply power and then release it after 1sec. The LED should be blinking fastly indicating a bind status and then fixed on. It's normal that the LED turns off when you press the bind button, this behavior is not controlled by the Atmega328.
###Protocol selection
For serial, leave all 4 selection pins unconnected.
For PPM, connect 1 to 4 of the selection protocol pins to GND.
The protocol/mode selection must be done before the power is applied.
