Modifications

Table of contents

• All optional hardware connections
• ExpressLRS/Crossfire
• Adjustable backlight level
• DFPlayer

All optional hardware connections

PCB Pad	Function
TX2	S.Port (CRSF) - required to connect ExpressLRS module
PA9	AUX Serial port TX - Telemetry mirror
PA10	AUX Serial port RX - SBUS Trainer
PA15	USB connection detection
PC13	External module power control (was PC9 up to OpenI6X 1.5.0)
PC9+BL	Wiring those together allows for adjustable backlight

ExpressLRS/Crossfire

Connection:

TX2  <----> S.Port
GND <----> GND

ExpressLRS elrsV3.lua equivalent is build in, no need to copy it to the radio. It can be used to configure both ExpressLRS and Crossfire modules.

Adjust port baudrate by going to: Radio Settings -> Hardware. Test available speeds and see which one works with your module.

Adjustable backlight level

Wire PC9 and BL pads together.

DFPlayer

Connection:

TX4  <----> DFPlayer RX
PC14 <----> DFPlayer BUSY
GND <----> GND

Tested DFPlayers:

• AB22A795251 - OK,
• GD3200D - OK,
• MH2024K-24SS - laggy, about 650ms delay, cannot keep up with timer count down, not recommended,