Temp Tracker

This is a hobby nerves project built to collect temperature data using one or many Rasbperry Pi device(s). The application is set up to run on both RPi3 and RPi Zero W. Temperature measurements are taken using the DS18B20 temperature sensor using the one-wire protocol with GPIO.

The application follows the poncho structure.

• temp_tracker_fw includes all nerves dependencies necessary and is used to build the firmware
• temp_tracker contains the business logic for measuring temperature data from the device
• temp_tracker_ui is a phoenix application and provides the web interface for reading measurements

Setup

To deploy the application, ensure your SSH key is set up. Set the local wifi credentials in your environment using NERVES_NETWORK_SSID and NERVES_NETWORK_PSK.

First, prep the Phoenix project:

# These steps only need to be done once.
cd temp_tracker_ui
mix deps.get
npm install --prefix assets

Build your assets and prepare them for deployment to the firmware:

# Still in temp_tracker_ui directory from the prior step.
# These steps need to be repeated when you change JS or CSS files.
npm install --prefix assets --production
npm run deploy --prefix assets
mix phx.digest

To build and push the firmware to an SD card:

cd ../temp_tracker_fw
export MIX_TARGET=rpi0
export NERVES_NETWORK_PSK=PASSKEY
export NERVES_NETWORK_SSID=SSID
mix deps.get
mix firmware
mix firmware.burn

Once the device is on the network,

mix upload nerves.local

To access the device's iex console:

ssh nerves.local