A Linux/Rust userspace driver for the Onsemi AX5043 transceiver.

Install Rust: https://www.rust-lang.org/tools/install

The expected use case is to be run on an ARM based machine like a Raspberry Pi or Beaglebone so a Rust crosscompiler setup will make development more convenient.

Install the cross toolchain: rustup target add armv7-unknown-linux-gnueabihf. !! Warning: The build libc must be <= target libc. Example error message:

lib/arm-linux-gnueabihf/libc.so.6: version `GLIBC_2.33' not found

On my setup my dev OS has a newer libc than Raspbian on the Pi and I'm unwilling to downgrade it. Two options:

• Upgrade RPI to Bookworm (might be viable now but wasn't at the time)
• Install older version of LLVM crosscompiler package

I went with the latter - toolchain: https://github.com/abhiTronix/raspberry-pi-cross-compilers

Modify .cargo/config, runner.sh

Handy commands:

• cargo run --example off --target armv7-unknown-linux-gnueabihf
• cargo r
• cargo b
• cargo c
• Combine the above with --examples (plural) flag to apply the action to all the examples

RUSTFLAGS='--cfg card="rpi"' cargo run --example tx --target armv7-unknown-linux-gnueabihf examples/rpi-uhf-60000.toml

Fresh Raspbian install

• https://www.raspberrypi.com/software/
• rpi-imager
  • Raspberry Pi OS (32-bit)
  • Internal SD Card Reader

sudo apt install rpi-imager

Be sure to check the advanced settings for ssh, wifi, and other useful settings

On the SD card mounted on my laptop

• touch <mountpoint>/boot/ssh to enable ssh
• uncomment dtparam=spi=on in /boot/config.txt to enable SPI0
• add dtoverlay=spi1-1cs to /boot/config.txt to enable SPI1

See:https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#spi-overview

Laptop wired connection config: IPv4 -> Shared to other computers Default IP on mine: 169.254.209.136 Default ssh login: pi@raspberrypi.local, pw:raspberry

Pinnout for Raspberry Pi 4B:

                     Pinnout:                       Colors:
                        J8                       VDD    -> Red
                       ----                      GND    -> Black
          TX VDD   1 - |oo| - 2                  IRQ    -> Gray
                   3 - |oo| - 4                  MOSI   -> Blue
                   5 - |oo| - 6                  MISO   -> Purple
                   7 - |oo| - 8                  SCLK   -> Green
          TX GND   9 - |oo| - 10                 SEI    -> Yellow
 (GPIO17) TX IRQ  11 - |oo| - 12 RX SEI (SPI1.0) SYSCLK -> Unused
                  13 - |oo| - 14
                  15 - |oo| - 16
          RX VDD  17 - |oo| - 18
 (SPI0.0) TX MISO 19 - |oo| - 20
 (SPI0.0) TX MOSI 21 - |oo| - 22
 (SPI0.0) TX SCLK 23 - |oo| - 24 TX SEI  (SPI0.0)
                  25 - |oo| - 26
                  27 - |oo| - 28
                  29 - |oo| - 30
                  31 - |oo| - 32
                  33 - |oo| - 34
 (SPI1.0) RX MISO 35 - |oo| - 36 RX IRQ  (GPIO16)
                  37 - |oo| - 38 RX MOSI (SPI1.0)
          RX GND  39 - |oo| - 40 RX SCLK (SPI1.0)
                       ----
                  GPIO EXPANSION

See https://datasheets.raspberrypi.com/rpi4/raspberry-pi-4-reduced-schematics.pdf

Libraries:

• https://www.kernel.org/doc/html/latest/spi/spidev.html
• https://www.kernel.org/doc/html/latest/driver-api/gpio/using-gpio.html

Other implemenations:

• https://notblackmagic.com/bitsnpieces/ax5043/
• https://gitlab.com/librespacefoundation/ax5043-driver
• https://github.com/oresat/oresat-firmware
• https://github.com/BrandenburgTech/DigitalTxRxRPi

List of docs (not committed for copywrite reasons):

• Datasheet
• Programming Manual
• ANs
• Demo board schematics

Examples

• off: Turns both radios off. Useful in case more complicated programs crash.
• dump: Resets radios and dumps all values. Useful for testing default values.
• tx: Simple transmit.
• rx: Simple receive.
• ground: Receives beacon packets on a socket and transmits them.
• roundtrip: Transmit from one radio and receive on the second.

Debian Packaging:

• Install cargo-deb: cargo install cargo-deb
• Build the deb: cargo deb --target armv7-unknown-linux-gnueabihf
• The resulting package can be found in target/armv7-unknown-linux-gnueabihf/debian/