Skip to content

Modifications

Janek edited this page Mar 13, 2025 · 35 revisions

Table of contents

All optional hardware connections

hw

PCB Pad Function
TX2 S.Port (CRSF) - required to connect ExpressLRS/Crossfire module
PA15 S.Port (CRSF) RX - only for CRSF_FULLDUPLEX enabled builds
PA9 AUX Serial port TX - Telemetry mirror
PA10 AUX Serial port RX - SBUS Trainer
PC13 External module power control (was PC9 up to OpenI6X 1.5.0)
PC14 DFPlayer BUSY
TXD4 DFPlayer RX
RXD4 FS-HZCZ03-ADJ Gimbal TX
PC9+BL Wiring those together enables adjustable backlight

ExpressLRS/Crossfire

Connection:

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

or for `CRSF_FULLDUPLEX` build:
TX2  <----> Module RX
PA15 <----> Module TX
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.

To adjust port baudrate go to: Radio Settings -> Hardware -> Baudrate. Test available speeds and see which one works best with your module.

Adjustable backlight level

Wire PC9 and BL pads together. Adjust backlight level in Radio setup menu.

hw

DFPlayer

Adds voice announcements capability.
Requires copying soundpack files directly to SDCard root catalog, sorted by filenames order. Numeric index in front of filenames is to maintain proper files order.

You can add 9 custom sounds under names:

0271_custm1.wav
0272_custm2.wav
0273_custm3.wav
0274_custm4.wav
0275_custm5.wav
0276_custm6.wav
0277_custm7.wav
0278_custm8.wav
0279_custm9.wav

Connection:

TXD4 <----> DFPlayer RX
PC14 <----> DFPlayer BUSY
GND  <----> GND

Tested DFPlayers:

  • AB22A795251 - OK,
  • GD3200D - OK,
  • GD3200A/B - laggy, too slow to set volume at boot, not recommended,
  • MH2024K-24SS - laggy, about 650ms delay, cannot keep up with timer count down, not recommended,

FlySky FS-HZCZ03-ADJ Gimbal

Requires custom firmware build with FLYSKY_GIMBAL=YES.

Connection:

RXD4 <----> FS-HZCZ03-ADJ Gimbal TX
GND  <----> GND

See also: https://github.com/EdgeTX/edgetx/wiki/Flysky-Hall-Sticks-Mod

External module power

External module power can be controlled using PC13 pad, so the module is automatically turned on or off. If your module have power enable pin (like it is with ELRS DIY TX) then you can wire PC13 directly to this pin, if you need this signal to be inverted, you need build with EXTPWR_INVERT=YES, otherwise you need to create power switch circuit.

Diagram below shows example circuit of mosfet switch:

extmod_power