How to use an SRXL2 receiver with the F405 V3 flight controller？ – SpeedyBee

Step 1: Please check whether the wiring between the receiver and the flight controller is correct.

It is recommended to refer to the wiring diagram in the manual of the flight controller to connect the receiver. Take the SpeedyBee F405 V3 flight controller as an example, you could refer to the following diagram.

Note : The signal wire(s) of the receiver should be correctly connected to the flight controller. For an SRXL 2 receiver, connect the SRXL 2 signal of the receiver to a free TX pad(instead of a RX pad) of the flight controller.

Step 2: Make sure the receiver is successfully bound to your radio transmitter

We suggest you refer to the receiver's manual and the transmitter's manual to verify if they are bound.

For example, the following video shows the transmitter's binding process:

https://youtu.be/gBXelft424A

Step 3: Check if the 'Serial Rx' is enabled for the receiver

For example, if your receiver is connected to UART 2, then you should enable 'Serial Rx' on UART 2.

Note: You can only enable one item in the whole UART row because one UART can only connect one peripheral. For example, if you set UART 2 as Serial Rx, you can't enable configuration/MSP, Telemetry Output, Sensor Input, or Peripherals.

Step 4: Set the correct receiver mode and provider.

For SRXL 2 receiver, please choose 'SRXL 2'

If the receiver channels have all turned white after setting the receiver protocol (as shown in the figure below).

Please check if the firmware version used is above Betaflight 4.4.0.

Betaflight 4.4.0 version has an updated Cloud-Build function, and you need to select the receiver protocol in advance before flashing the firmware (SRXL2).

You can refer to the following article for specific flashing methods：

How to correctly flash Betaflight 4.4 firmware.

Step 5: Check if your transmitter can be detected in the Betaflight configurator.

Connect your flight controller to the Betaflight configurator > Receiver tab, move the sticks or toggle the switches to see if the Betaflight UI can show the input correspondingly.

NOTE： for some receivers, you must keep them at least 0.5 meters far away from the transmitter to prevent the connection from being disconnected automatically.