A PID (climate) controller for Home Assistant to heat something using a thermometer and a SSR relay. Here is an example of a card that shows up in Home Assistant:
Enable mqtt discovery.
- Add a custom fleet configuration variable in project:
BALENA_HOST_CONFIG_dtoverlay=w1-gpio
- Add remote your balena remote:
git remote add balena <USERNAME>@git.balena-cloud.com:<USERNAME>/<APPNAME>.git
- Push to balena:
git push balena master
| Environmental variable | Required | Default | Description |
|---|---|---|---|
| LOG_LEVEL | no | info | Log level for application, i.e debug, info, warn, error |
| HA_COMPONENT_PREFIX | no | Brew | Prefix for component names |
| HA_AVAILABLE | no | false | Send available message to HA on startup |
| HA_AUTO | no | false | Send auto discovery messages to HA on startup |
| HA_PRINT_CONFIG | no | false | Print HA config on startup |
| SSR_PIN | no | GPIO18 | Pin name on the Raspberry PI the SSR is connected to |
| MQTT_HOST | no | localhost | The host of the MQTT server to communicate with HA |
| MQTT_USER | no | MQTT user | |
| MQTT_PASS | no | MQTT pass | |
| PID_P_GAIN | no | 2 | PID proportional gain |
| PID_I_GAIN | no | 5 | PID integral gain |
| PID_D_GAIN | no | 1 | PID derivative gain |
| PID_OUTPUT_LIMIT | no | 5 | PID output limit when calculating control percentage |
| PID_SAMPLE_TIME | no | 8 | Amount of time between each PID update |
| SIMULATE | no | false | Set this to true if you want to simulate thermometer and relays |
| SLEEP_PER_ITERATION | no | 0 | Sleep per loop iteration, useful to set while simulating |
Component names may differ, but for simulation you can use the HA config and HA dash config in this repository.
Here is how the dashboard can look like in HA:
VERY IMPORTANT NOTE: THIS IS NOT A HOW-TO instructional guide. This explains how I used a Raspberry Pi to control electric current. However, I am NOT an electrician, and just because I did something doesn’t mean YOU should, particularly if you are unfamiliar with how to wire electrical devices safely. If you choose to follow the method I used, you do so at your own risk.
