spi

An Erlang application for interfacing with SPI devices on Linux systems.

Setup

You need to add spi as a dependency to your project. If you are using rebar3, you can add the following to your rebar.config:

{deps, [
    {spi, "0.5.0"}
]}.

Also ensure that spi is added as a dependency to your application, by updating your .app.src file:

{application, my_app, [

    {applications, [
        kernel,
        stdlib,

        spi  % <- You need this in your applications list
    ]}
]}.

Usage

The following will open /dev/spidev0.0 using mode 0, at 10MHz using 8 bits per word:

> {ok, Device} = spi:open("/dev/spidev0.0", #{
    mode => 0,
    speed_hz => 10000000,
    bits_per_word => 8
}).
{ok, #Ref<0.2893647232.3229876230.113792>}

Once the device is open you need to use spi:transfer/2 to initiate a transfer. Alternatively spi:read/2, spi:read/3, spi:write/2 and spi:write/3 can also be used for simple transfers.