Relay is not working

Relay is not working on my matek h743

My FC is matek H743
Pls check my pic.
This is my first time using relay to add smoke on my plane. But Relay is not working.
Am i doing Right?

Hey, in my opinion (I am no expert) you have to try an other value on servo5_function.
Eather a camera number (10,90-94), since the description of first relay pin is the pin used for camera shutter, or something else.
You can supervise the servo output in the setup section and see what’s on the pin linked to your relay.

Those relay modules are pulled low to activate, you really want a set like these red ones that have a jumper to set them to activate with a high level signal. im sure I had issues getting the blue boards to work so moved on to these.


You must set servo6 output to GPIO. SERVO_GPIO_MASK is not necessary, leave it as 0.


Then set rc channel 8 as a relay switch


On the Matek website is a list of the GPIO numbers.
Flight Controller H743-WING V2/V3 – Matek Systems
PWM S6 is GPIO 55.
Assign this GPIO number to the relay1


Then reboot. Thats all. Now servo6 output is low (0 volt) at ch8=1000µs and high (3.3v) at ch8=2000µs