Pinouts and Pads

Tx1/Rx1(UART1) for CRSF protocol Receiver

Tx2/Rx2(UART2) for GPS/firmware update/setting parameters

1~10: CH1~CH10 PWM outputs

Curr: current sensor signal (0~3.3V)

Vbat: Battery voltage sensing (0~36V)

G: ground

4v5 pad voltage = 5V pad voltage -0.3V,  make sure the voltage on 5V pad is not higher than receiver and GPS rated voltage.

Failsafe

Failsafe value is set automatically after CRSF-PWM board is powered on and receive CRSF signal. LED blinks 8 times quickly.

Failsafe value = The PWM value of each channel(except CH3) when CRSF signal is received by CRSF-PWM board for the first time

CH3 is specially arranged for the throttle,  Failsafe value = 988 by default.

Usually put the Throttle  joystick to the lowest point,  put AIL(Roll), ELE(Pitch), RUD(Yaw) middle before powering on receiver.

LED status

slow blinks: CRSF-PWM board doesn’t receive CRSF signal, e.g., receiver is not bound with transmitter, receiver is not connected to UART1 of CRSF-PWM board.

8x quick blinks: CRSF-PWM board received CRSF signal and failsafe value is saved.

solid ON:  CRSF-PWM board and receiver are working normally

2x slow blinks between 8x fast blink and solid on: CLI mode is active

GPS telemetry

Compatible with GPS NMEA protocol

GPS “TX” to CRSF-PWM board “RX” Single wire half duplex UART connection,   CRSF-PWM board “TX” to GPS “RX” is not essential.

Support GPS Telemetry ID: GPS, GSpd, Hdg, Alt, Sats

u-blox series GPS can output “0+1 – UBX+NMEA” protocol by default

Sensors(GPS, GSpd, Hdg, Alt, Sats) will blink in Transmitter TELEMETRY tab once CRSF-PWM board has connection with GPS.

Troubleshooting for no GPS telemetry,  double check the wiring between GPS and CRSF-PWM board,  some u-blox GPS may don’t output NMEA protcol, you need to be reverted GPS to default configuration in u-center.

with OpenTX Telemetry Logging, You can plot your flight path or search the lost plane.

TIM & PWM Frequency

PWM frequency on all 10x Channels can be configured according to TIM

PWM run at 50Hz by default

TIM2:  CH1, CH2, CH4

TIM16: CH3

TIM3:  CH5, CH6, CH7, CH8

TIM1:  CH9, CH10

CLI mode

If CRSF-PWM board doesn’t detect GPS connected to UART2 within 10 seconds after powering on,  CLI mode will active.

After CLI mode is active, CRSF-PWM board can be connected to configurator via USB-TTL module/FC passthrough.

in CLI mode, CRSF-PWM board firmware can be updated

CLI mode has no effect to receiver CRSF signal and PWM outputs

1x Matek CRSF to PWM Converter With Current Sensor (ELRS Compatible)

1x Pin set

MANUAL & Firmware