Mateksys CRSF to PWM Converter

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(CRSF-PWM-6 and -C ): (0~36V) Battery voltage sensing
• Vbat(CRSF-PWM-B) ): (6~30V) Battery voltage sensing and power supply of onboard BEC
• 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 (FW 1.1.1 or older)

• 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.

Failsafe (FW 2.0.0 or newer)

• CH3 is arranged for the throttle, Failsafe value = 988 by default. you can change the failsafe value of CH3 and other channels by following settings.
• Make sure ESC signal is disconnected from CRSF-PWM board before starting failsafe settings
• Bridge PWM1 and PWM2 signal pad, then power on CRSF-PWM board and receiver.
• Failsafe value will be saved automatically after CRSF-PWM board is powered on and receive CRSF signal. LED blinks 8 times quickly.
• Failsafe value = The PWM value of each transmitter channel when CRSF signal is received by CRSF-PWM board.
• Remove the jumper between PWM 1 and 2, then CRSF-PWM board will work in normal PWM output mode.

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. (firmware 1.1.1 or older)
• solid ON: CRSF-PWM board and receiver are working normally
• 2x slow blinks between 8x fast blink and solid on: CLI mode is active (firmware 1.1.1 or older)

GPS telemetry

• Compatible with GPS NMEA protocol, 1Hz, Baud 9600~115200
• 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 revert GPS to default configuration in u-center.
• with OpenTX Telemetry Logging, You can plot your flight path or search the lost plane.

VSpd telemetry (Vario)

• VSpd telemetry is supported by ExpressLRS 2.0, EDGE 2.6, OPENTX 2.2 or newer.
• support barometer MS5611(I2C address 0x77) and SPL06-001 (I2C address 0x76)

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

Firmware update

• Tool: Matek Configurator
• Firmwares: CRSF_PWM_fw.zip

————————————————— Firmware v2.4.3, May 4, 2023

• Fix bug of GPS data lost in telemetry log
• changed GPS speed unit to km/h
• modify set output_5 = ch[x] range to 1-16 , you can ramap output_5 to any CH within 1-16
• modify set current_scale = range to 50-2000

Firmware v2.3.0, May 13, 2022

• Add Baro_Alt telemetry ID in CRSF protocol
• EdgeTX 2.7.1/OpenTX 2.3.15 or newer for Transmitter OS, ExpressLRS 2.5 or newer for TX module and Receiver.

Firmware v2.2.0, Apr.16,2022,

• Fix compatibility issue with TBS Tracer/Crossfire V3. If you are using ELRS receiver, updating to V2.2.0 is not a must.

Firmware v2.1.0, Mar.1,2022,

• WARNING: Failsafe settings is a must after upgrading from V1.x.x to V2.x.x
• support Barometer MS5611 (I2C address 0x77) and SPL06-001 (I2C address 0x76) via I2C(DA,CL pad).
  • There are no I2C pull-up resistors on CRSF-PWM-6 and CRSF-PWM-C board, make sure the pull-up resistors are available on external MS5611 or SPL06-001 module. you may test the resistance between SCL and 3v3, SDA and 3v3, if there is pull-up resistor, the resistance should be 1~10K ohm.
• Failsafe settings
  • CH3 is arranged for the throttle, Failsafe value = 988 by default. you can change the failsafe value of CH3 and other channels by following settings.
  • Make sure ESC signal is disconnected from CRSF-PWM board before starting failsafe settings
  • Bridge PWM1 and PWM2 signal pad, then power on CRSF-PWM board and receiver at same time.
  • Failsafe value will be saved automatically after CRSF-PWM board is powered on and receive CRSF signal. LED blinks 8 times quickly.
  • Failsafe value = The PWM value of each transmitter channel when CRSF signal is received by CRSF-PWM board.
  • Remove the jumper between PWM 1 and 2, then CRSF-PWM board will work in normal PWM output mode.
• Fix GPS coordinates display for Southern hemisphere & Western hemisphere

v1.1.1, Dec.05,2021

• add CLI command “set output_5 = ch[x](11 or 12)”

Upgrade CRSF-PWM via A or B

A. USB-TTL modules, such as CP210x, FTDI

1. Wiring

• TX2 — USB-TTL module RX
• RX2 — USB-TTL module TX
• 4v5 — USB-TTL module 5V
• G — USB-TTL module GND

2. Connect USB-TTL module to PC 3. CRSF-PWM board CLI mode will active after powering on for 10 seconds 4. Open Matek configurator, Select COM port of USB-TTL, Baud rate 115200, Click “Connect” 5. OpenFile “CRSF_pwm_vx.x.x.bin” 6. Click “Upgrade”

B. INAV/BF serial passthrough

1. Wiring

• TX2 — FC any spare UART_RX
• RX2 — FC any spare UART_TX
• 4v5 — FC 5V or 4V5
• G — FC GND

2. Connect FC USB to PC 3. CRSF-PWM board CLI mode will active after powering on for 10 seconds 4. open INAV/BF configurator, connect FC to configurator 5. click INAV/BF configurator “CLI” tab, type “serialpassthrough x 115200”, x = UART number -1, e.g. CRSF-PWM board connect to FC UART4, type “serialpassthrough 3 115200”. 6. Disconnect FC from configurator, make sure USB is still plugged in FC and CRSF-PWM board is still powered on. 7. Open Matek configurator, Select COM port of Flight controler, Baud rate 115200, Click “Connect” 8. OpenFile “CRSF_pwm_vx.x.x.bin” 9. Click “Upgrade”

comparision

SKU	CRSF-PWM-6	CRSF-PWM-C	CRSF-PWM-B	CRSF-PWM-V10	CRSF-PWM-V ELRS-R24-V
RF Frequency	compatible with any CRSF protocol receivers (including 433MHz, 868MHz, 915MHz, 2.4GHz)
PWM outputs	6	10	8	10	7
CH remapping	set output_5 = ch11 or ch12
PWM frequency	50, 100, 160, 330, 400Hz
Telemetry ID	RSSI, Qly SNR,  RxBt, Curr, Capa, Bat%, GPS, GSpd, Hdg, Alt, Sats, VSpd, Baro Alt
Vbat pad	0~36V	0~36V	6~30V	0~36V	0~36V
Current sensor	external	90A/220A	external	external	external
BEC	external	external	5V/6V  5A	external	external
Barometer	external	external	external	SPL06-001	SPL06-001
PCB Size(mm)	25*16	26*26	33*21	27*16	38*16