/nerves_system_sama5d27_wlsom1_ek

Nerves system for ATSAMA5D27-WLSOM1 Evaluation Kit

Primary LanguageElixirApache License 2.0Apache-2.0

ATSAMA5D27-WLSOM1 Evaluation Kit

https://www.microchip.com/DevelopmentTools/ProductDetails/PartNO/DM320117

ATSAMA5D27-WLSOM1 Evaluation Kit image
Image credit

Feature Description
CPU 500 MHz ARM Cortex-A5
Memory 256M DDR2
Storage MicroSD
GPIO, I2C, SPI Yes - Elixir Circuits
UART ttyS0
Ethernet Yes
Video Yes
Camera Interface Yes - Parallel ISC

Using

The most common way of using this Nerves System is create a project with mix nerves.new and to export MIX_TARGET=sama5d27_wlsom1_ek. See the Getting started guide for more information.

If you need custom modifications to this system for your device, clone this repository and update as described in Making custom systems

Wifi

The WLSOM1 contains a ATWILC3000 Wifi / Bluetooth module. Wifi can be enabled by loading the kernel module.

iex> System.cmd("modprobe", ["wilc-sdio"])

Supported USB WiFi Devices

The base image includes drivers and firmware for Ralink RT53xx (rt2800usb driver) and RealTek RTL8712U (r8712u driver) devices.

We are still working out which subset of all possible WiFi dongles to support in our images. At some point, we may have the option to support all dongles and selectively install modules at packaging time, but until then, these drivers and their associated firmware blobs add significantly to Nerves release images.

If you are unsure what driver your WiFi dongle requires, run Debian and configure WiFi for your device. At a shell prompt, run lsmod to see which drivers are loaded. Running dmesg may also give a clue. When using dmesg, reinsert the USB dongle to generate new log messages if you don't see them.

Provisioning devices

This system supports storing provisioning information in a small key-value store outside of any filesystem. Provisioning is an optional step and reasonable defaults are provided if this is missing.

Provisioning information can be queried using the Nerves.Runtime KV store's Nerves.Runtime.KV.get/1 function.

Keys used by this system are:

Key Example Value Description
nerves_serial_number "12345678" By default, this string is used to create unique hostnames and Erlang node names.

The normal procedure would be to set these keys once in manufacturing or before deployment and then leave them alone.

For example, to provision a serial number on a running device, run the following and reboot:

iex> cmd("fw_setenv nerves_serial_number 12345678")

This system supports setting the serial number offline. To do this, set the NERVES_SERIAL_NUMBER environment variable when burning the firmware. If you're programming MicroSD cards using fwup, the commandline is:

sudo NERVES_SERIAL_NUMBER=12345678 fwup path_to_firmware.fw

Serial numbers are stored on the MicroSD card so if the MicroSD card is replaced, the serial number will need to be reprogrammed. The numbers are stored in a U-boot environment block. This is a special region that is separate from the application partition so reformatting the application partition will not lose the serial number or any other data stored in this block.

Additional key value pairs can be provisioned by overriding the default provisioning.conf file location by setting the environment variable NERVES_PROVISIONING=/path/to/provisioning.conf. The default provisioning.conf will set the nerves_serial_number, if you override the location to this file, you will be responsible for setting this yourself.