• “Any ELRS 2.4Ghz receivers can work with any ELRS 2.4Ghz TX Modules, from any manufacturer and even the DIY ones. This is as long as they have the same binding phrase and configuration options (Regulatory Domain, Performance Options and Extra Data).”
• More details about ExpressLRS, pls check out  ExpressLRS wiki
• Receivers have ExpressLRS fw preloaded with BINDING_PHRASE for QC,  the Receiver will never enter binding mode using the traditional binding procedure. 
• Traditional binding is not recommended.  You’d better flash it with your binding phrase.

Wiring with FC

• Receiver RX — FC UART_TX  for Telemetry
• Receiver TX — FC UART_RX  for Control
• Receiver 5V — FC 5V or 4v5
• Receiver G — FC GND
• Receiver protocol: Serial-based receiver – CRSF

Flashing with ELRS configurator

• Wire the receiver into the USB-TTL adapter, with TX on receiver connected to the Rx on the USB-TTL, and RX on receiver connected to the Tx of the USB-TTL. Wire 5V and GND of the USB-TTL to 5V and GND of the Receiver.  Press the boot button while powering the RX on, and release – the LED should now be solid.
• Select the target MATEK R24-D 2.4GHz RX ( for ELRS-R24-D) / MATEK R24-S 2.4GHz RX ( for ELRS-R24-S) and  “UART” for Flashing Method,  set your bind phrase and Firmware Options,  Check “erase before flash” and “Force FLash “, once done, click on Flash.

Troubleshooting

• If receiver can’t be flashed via WIFI or BFpassthrough when it come with preloaded firmware. You may recover it by flashing it via UART.