rpi-relay-hat-api

• Install dependencies (on Raspberry Pi only)
  • Install pigpio
  • Symlink node, npm & yarn
• Install and run the package
  • Configure the application
  • Run the package
• Development options
  • Download the package
  • Build application
  • Configure the application for development
  • Run
  • Test
  • Publish
• Endpoints
  • GET /
  • GET /sys-info
  • GET /:id
  • POST /:id/on
  • POST /:id/off
  • POST /:id/toggle
• Managed process
  • Install pm2
  • Add process to startup script

An API to control the Waveshare RPi Relay Board.

Install dependencies (on Raspberry Pi only)

Install pigpio

sudo apt-get update
sudo apt-get install pigpio

Symlink node, npm & yarn

https://github.com/fivdi/pigpio/issues/124

sudo ln -s "$(which node)" /usr/local/bin/node
sudo ln -s "$(which npm)" /usr/local/bin/npm
sudo ln -s "$(which yarn)" /usr/local/bin/yarn

Install and run the package

yarn dlx rpi-relay-hat-api

Configure the application

Create a rpi-relay-hat-api.env file (in a globally accessible location will allow it to be run as a service, e.g. within /usr/lib/node_modules/rpi-relay-hat-api/) and add details of the channels and server port, something like:

RELAY_HAT_CHANNELS=[{ "channelId": "CH1", "pinNo": 26, "mode": 1, "name": "Mirror Light" }, { "channelId": "CH2", "pinNo": 20, "mode": 1, "name": "Mirror Demister" }]
PORT=3000

| Property | Type | Meaning | Example | |----------|------|---------|---------| | channelId | string | Unique identifier in the format CH{n}, where n is a number between 1 and 9 | CH1 | | pinNo | number | BCM pin number, as per RPi Relay Board - Interface description | 20, 21, or 26 | | mode | number | Default value, 0 for off and 1 for on | 0 or 1 | | name | string | The display name for the switch | Mirror Light |

Run the package

ENV_FILE_PATH=/usr/lib/node_modules/rpi-relay-hat-api/rpi-relay-hat-api.env rpi-relay-hat-api

Development options

Rather than installing the package, these development options allow it to be run and tested:

Download the package

git clone [email protected]:jondarrer/rpi-relay-hat-api
cd rpi-relay-hat-api

Build application

yarn
yarn build

Configure the application for development

Create a .env file and add details of the channels and server port, something like:

RELAY_HAT_CHANNELS=[{ "channelId": "CH1", "pinNo": 26, "mode": 1, "name": "Mirror Light" }, { "channelId": "CH2", "pinNo": 20, "mode": 1, "name": "Mirror Demister" }]
PORT=3000

Run

sudo yarn start

Test

yarn test

Publish

npm version patch -m "%s"
git push && git push --tags

And then create a release based on the tag in GitHub; this will then run the GitHub action to publish the package on npmjs.com.

Endpoints

GET /

Get details of all available relays.

GET /sys-info

Get info about current system.

GET /:id

Get details of a particular relay.

POST /:id/on

Turn a relay on (digital write 1).

POST /:id/off

Turn a relay off (digital write 0).

POST /:id/toggle

Toggles a relay on and off (digital write 1 or 0), inverting its previous state.

Managed process

Use pm2 to setup the script when booting up.

Install pm2

npm i -g pm2
sudo ln -s "$(which pm2)" /usr/local/bin/pm2

Add process to startup script

sudo pm2 start "ENV_FILE_PATH=/home/jondarrer/code/rpi-relay-hat-api/.env sudo yarn --cwd /home/jondarrer/code/rpi-relay-hat-api start" --name "waveshare-api"
sudo pm2 startup
sudo pm2 save
# sudo pm2 stop waveshare-api
# sudo pm2 restart waveshare-api
# sudo pm2 delete waveshare-api