TODO
This is where I'll document how to install a transceiver board onto your flight controllers as well as how what adjustments you may need to perform to various configuration files (mostly header files).
Using onboard SPI
The FlySky version of the MATEKF411RX
target ("HappyModel Crazybee F4 Lite 1S" flight controller found on the Mobula6) and
the CRAZYBEEF3FS
target both have on-board SPI transceiver modules. This makes it super easy to use with SilverLite-FC.
The only thing you need to configure is whether you want to use the older AFHDS protocol (which has a minimal latency of 1.5ms)
or the newer AFHDS2A protocol (minimal latency of 3.850ms).
I prefer using the older AFHDS protocol because it lets me use just one model with my TX rather than having to have models for every whoop/micro I have. Plus it has the lowest latency of all the mainstream protocols (1.5ms or 666 packets per second).
For external SPI modules
Things to discuss:
- Describe the available choices of transceiver modules
- NRF24L01
- Comes in different form factors
- The micro version like this one on Amazon works well.
- Many ebay, Aliexpress listings say they are NRF24L01 but are something completely different (not even a clone of the NRF24L01), so beware!
- With Play F4 board you must use capacitor across +3.3v and GND due to the noisy power supply. In comparison the XN297L seemed okay without a cap on the Play F4.
- Comes in different form factors
- XN297L
- Uses 3-wire SPI
- Easily harvested from H8mini transmitter
- LT8900
- Requires an extra pin or a resister/capacitor combo to perform a reset on power-on.
- Requires a customized multiprotocol module firmware. I built a custom TX variant for this but never pushed this up to github.
- NRF24L01
- Need to edit
_my_config.h
to specify which transceiver module you're using. Just need to define only one of the following choices:TRX_NRF
TRX_XN297
TRX_XN297L
TRX_LT8900
- Need to edit
_my_config.h
to specify if you'll be using 3-wire SPI or 4-wire SPI- Enable the
TRX_SPI_3WIRE
for 3-wire, otherwise it will be 4-wire
- Enable the
- Need to edit
trx_spi_config.h
to specify which STM32 pins to use for the software SPI.- The Play F4 and NRF24L01 section has more detail on this.
- Wiring considerations
- Avoid inductor coil
- Antenna mods