Matek mLRS MAVLink 868/900MHz Receiver, mR900-22

Looking for a lightweight, reliable long-range solution for your drone or telemetry system? The Matek mR900-22 MAVLink Long Range Receiver might be your perfect match. Operating on the 900 MHz LoRa band with a maximum RF power output of 158mW, it’s ideal for those who value stability and efficiency over vast distances. With MAVLink firmware built in, this receiver is ready to provide precise communication across long-range UAV setups.

But beware, the mR900-22 isn’t here to make friends with ELRS 900MHz or FrSky R9 systems running SX127x chips—it won’t bind. Instead, it gets along just fine with other LoRa SX126x systems and STM32WLE5xx-based devices, like the WIO-E5 or mR900-30.

Key Features:

• 20 dBm RF Power: Delivers reliable transmission strength for long-range connectivity (up to 158mW).
• MAVLink Compatible: Designed to communicate seamlessly with UAV systems using MAVLink.
• Dual Buttons for Boot & Bind Modes: Simple setup for bootloader and pairing.
• LoRa SX1262 Chip: Ensures compatibility with other STM32WLE5xx systems.
• Versatile Outputs: Supports CRSF or SBUS for RC control outputs.

Specifications

• STM32WLE5CC with TCXO,  mLRS firmware
• RF Frequency: 900MHz (868MHz, 915MHz FCC)
• RF power: -9dBm(min) / 0dBm / 10dBm / 20dBm / 22dBm(158mW)
• Antenna connector: IPEX MHF-1
• TX2/RX2: Bi-directional Serial MAVLink
• TX1: RC out(CRSF or SBUS)
• 2x buttons for Boot mode and Bind

• Power supply: 4-9V DC @ “V” Pad
• Power dissipation:  Average 67mA/Peak 170mA@5V IN(31Hz, 22dbm)
• PCB Size: 24 x 15.5 mm
• Weight: 2.3g w/ antenna

• Packing:
  • 1x mR900-22
  • 1x IPEX MHF1 dipole antenna. 8cm

LED Status

• [Red flashing 2Hz], not connected to transmitter
• [Green flashing 1Hz], connected to transmitter
• [Red and Green alternately ], Binding mode enabled

Binding

• After powering on,  press the bind button (for ca. 4 seconds) on the receiver. When in bind mode, the green and red LEDs will blink alternatively with ca 2.5 Hz.
• https://github.com/olliw42/mLRS-docu/blob/master/docs/BINDING.md

Firmware

• mLRS https://github.com/olliw42/mLRS/tree/main/firmware/pre-release-stm32
• Targets:   rx-matek-mr900-22-wle5cc-xxx

Tips

• mLRS Github  & Documentation
• mLRS Discord
• mLRS Facebook group
• If set RF power >=500mW, It is recommended to attach the heatsink to the bottom side of PCB. The gaps between fins can be used for mounting with M3 screws
• mR900-22 is NOT compatible with ELRS 900MHz / Frsky R9 series using the SX127x. They will not bind with each other.

Wiring

Modes and Link Rates

Firmware Flashing

Download STM32CubeProgrammer from ST website

• https://www.st.com/en/development-tools/stm32cubeprog.html

mLRS firmware:

• https://github.com/olliw42/mLRS/tree/main/firmware/pre-release-stm32
• Targets:   rx-matek-mr900-22-wle5cc-xxx

Connect the mR900-22 to USB-TTL module (e.g.CP210x, FTDI)

• mR900-22 RX2  —  USB-TTL module TX
• mR900-22 TX2  —  USB-TTL module RX
• mR900-22  V   —  USB-TTL module 5V
• mR900-22  G   —  USB-TTL module GND

Connect USB-TTL module to computer while holding the receiver boot button in.

1. Select UART
2. Select the COM port of USB-TTL module
3. Connect
4. select “Erasing & Programming”
5. Tick all sectors and click “erase selected sectors”
6. Browse firmware (hex or bin file) related to the hardware.
7. Click “Start Programming”
8. After programming, unplug USB and plug USB back in. If red LED blinks at 2Hz, the receiver is waiting for connecting with transmitter.