SensorPi

In order to build nerves system on OS X both folders /var/folders and /private/var/folders must be shared in Docker. Since Docker UI on OS X does not allow setting both (/var/folders) cannot be selected configuration file /Library/Group\ Containers/group.com.docker/settings.json must be edited and following two lines

   “\/var\/folders”,
   “\/private\/var\/folders”

must be added to filesharingDirectories.

Further, build is done here, customized Nerves version is expected to be in ../dht_rpi3 folder as is visible in file mix.exs in the deps function where nerves_system_dht_rpi3 dependency is set.

Basically steps are following

• In the dht_rpi3 folder fetch changes from upstream with git fetch upstream and merge them to master
• In this project in mix.exs file adjust versions for nerves_system_rpi3 if needed
• Run WIFI_SSID=<wifi_network_name> WIFI_PSK=<wifi_password> MIX_TARGET=dht_rpi3 mix firmware to build firmware
• Run WIFI_SSID=<wifi_network_name> WIFI_PSK=<wifi_password> MIX_TARGET=dht_rpi3 ./upload.sh <rpi_ip_address> to upload firmware

Targets

Nerves applications produce images for hardware targets based on the MIX_TARGET environment variable. If MIX_TARGET is unset, mix builds an image that runs on the host (e.g., your laptop). This is useful for executing logic tests, running utilities, and debugging. Other targets are represented by a short name like rpi3 that maps to a Nerves system image for that platform. All of this logic is in the generated mix.exs and may be customized. For more information about targets see:

https://hexdocs.pm/nerves/targets.html#content

Getting Started

To start your Nerves app:

• export MIX_TARGET=my_target or prefix every command with MIX_TARGET=my_target. For example, MIX_TARGET=rpi3
• Install dependencies with mix deps.get
• Create firmware with mix firmware
• Burn to an SD card with mix firmware.burn

Learn more

• Official docs: https://hexdocs.pm/nerves/getting-started.html
• Official website: https://nerves-project.org/
• Forum: https://elixirforum.com/c/nerves-forum
• Discussion Slack elixir-lang #nerves (Invite)
• Source: https://github.com/nerves-project/nerves