FS I6 with FS-IA6 and SPRacing F3 -> flashing red status light, RX Loss error in Betaflight


#1

Hi,
I’m struggling to get my SPRacing F3 flight controller (and Betaflight) to see the FS-IA6 receiver. This is the unmannedtech qav210 kit with the video/written guide on this site. Things I’ve done so far:

  • Binding the FS-I6 transmitter with the FS-IA6 receiver seems fine - stable red light on the receiver
  • Aux 5 and 6 on the transmitter are set to see the switches on the transmitter as instructed.
  • The main battery is attached to the quad
  • The USB cable is attached to the quad and I’ve flashed the flight controller in betaflight with the latest firmware - can’t get Cleanflight to do this for some reason.
  • Betaflight shows the quad and reacts to movement in the graphical display. I can also spin the motors via Betaflight
  • I’ve enabled Serial RX for UART3 - following the QAV210 build video using IO1/IO2 pins.
  • Receiver settings in Betaflight are set to PPM - as I’ve read that the FS-I6 doesn’t support IBUS.
  • AERT1234 is selected in Betaflight

The CLI status command returns an RXLoss error, the board status light flashes red, and I get no response in Betaflight to any changes on the transmitter. It seems the receiver and the flight controller aren’t communicating. Am I meant to somehow further bind the transmitter controls for Betaflight to respond? What am I missing?

Any help is much appreciated
Thanks, Steve


#2

The solution to the above was to set the receiver input in betaflight to PWM, not PPM. IO1/2 are using PWM, each channel having its own wire from the receiver to the FC.
I could rule out a receiver fault by putting a voltmeter between the ground and each channel pin on the FS-IA6, flicking switches and moving sticks on the transmitter to watch the voltage change.


#3

The downside to using PWM is you cannot use any of the ESC BlHeli serial protocols like Oneshot, Oneshot125, etc. To use BLHeli you must use a serial receiver protocol like PPM, S.Bus, or IBUS.


#4

Thanks for the reply.

Given the kit contents (FS-I6, FS-IA6, SPRacing F3) and the dronetrest guide showing connecting the receiver and FC using IO1/2, I assume I can’t use PPM. Would you know if that’s correct?


#5

I use a Taranis, so I know diddly about FlySky.

Try posting your radio questions here: RCG Radios Forum


#6

The FS-IA6 doesn’t support PPM