Hey everyone, I’m new to working with hardware and decided to learn by interfacing with some MAX31855 thermocouple sensors. I’ve successfully read temperatures from them using a software SPI, basically doing all of the CLK switching manually, and decided to give the hardware SPI a try but I’m unsure how to correctly interface with it.
I’m using the Circuits.SPI library. I’ve connected the MAX31855 pins according to this layout
DO → SPI_MISO
CLK → SPI_SCLK
CS → SPI_CE0
I’ve done Circuits.SPI.bus_name which returns ["spidev0.0", "spidev0.1"] I assume spidev0.0 corresponds to CE0, so I then proceeded to do SPI.open("spidev0.0", speed_hz: 5_000_000, delay_ns: 100) The opts I’ve added by looking at the MAX31855 datasheet (https://datasheets.maximintegrated.com/en/ds/MAX31855.pdf). I’m really not sure what to do from here, I’ve tried, as a test, SPI.transfer(ref, <<0>>) and it just returns {:ok, <<0>>}.
Any help would be appreciated as I’m pretty lost here since the example for Circuits.SPI is interfacing with an ADC.
