Custom Protocol with HA

Adding your own custom device is easy (YMMV), and extremely satisfying (IMHO). With more simple signals, you maybe able to utilize the native tools to record and listen for particular signals. This isn't meant to be a beginning-to-end tutorial as there's amble documentation available for setting up the prerequisites and the variable definitions. The intent is the quick-and-dirty I wish I had found to quickly get some request that I could then tailor for my application.

For example, I wanted to integrate a Wonderful Home D10 doorbell into Home Assistant, but the device was not natively supported by rtl_433, so I created a custom integration.

First step: Research your device's frequency. I'd advise you take advantage of public FCC documentation. In my application, the frequency was 433875000 Mhz, so I created a file here: /homeassistant/rtl_433/rtl_Spa.conf.template with the following: ``output kv`

output mqtt://192.168.1.100:1883,user=<username>,pass=<password>

frequency 433875000 `analyze_pulses true``

Obviously you need to replace the IP address, username, password, and frequency with the particulars of your configuration and device.

Going to Settings -> Add-ons -> rtl_433 and Starting/Restarting, I was provided this line (in a mix of a larger output) on the Log tab: '[rtl_Spa] Use a flex decoder with -X 'n=name,m=OOK_PWM,s=172,l=564,r=1800,g=624,t=157,y=0' [rtl_Spa] [01] {33} 14 8d df b9 80 : 00010100 10001101 11011111 10111001 1'

I then edited my /homeassistant/rtl_433/rtl_Spa.conf.template with the lot output's data as follows: 'output kv

output mqtt://192.168.82.113:1883,user=,pass=

frequency 433875000

decoder { name=Wonderful_Home_Doorbell, modulation=OOK_PWM, short=156, long=548, reset=1832, gap=652, tolerance=157, match={33}0x148DDFB98 unique, }'

Home Assistant, at that point, could 'see' the device if I told MQTT to 'Listen to a topic', but it wasn't yet an automation. As my device was a simple binary 'button press' or 'button not pressed' signal, I started out trying to look at the data received in MQTT for a match to my expected String (14 8d df b9 80), but found that parsing the JSON data was frustrating as I couldn't be guaranteed any particular row of data would have my String. Fortunately, as my device only sent a signal when the button was pressed, I didn't care about times it wasn't pressed, so I scratched looking at the data field and only looked at the time stamp for my automation.

In other words, I created a Sensor in a *.yaml file: 'mqtt: sensor: - name: "Spa Doorbell Time" state_topic: "rtl_433/+/events/#" value_template: "{{ value_json.time }}"'

And then I created an Automation that sends a notice to my cell when the time stamp of the door bell changes (in other words, when someone presses the button): 'alias: Spa_Doorbell description: "" trigger:

• platform: state entity_id:
  • sensor.spa_doorbell_time id: Doorbell_State_Change_Trigger condition:
• condition: and conditions:
  • condition: template value_template: "{{ states('sensor.spa_doorbell_time') != 'unknown' }}"
  • condition: template value_template: "{{ states('sensor.spa_doorbell_time') != 'unavailable' }}"
  • condition: template value_template: "{{ trigger.from_state != trigger.to_state}}"
  • condition: template value_template: "{{ trigger.to_state != 'unavailable'}}"
  • condition: template value_template: "{{ trigger.to_state != 'unknown'}}" action:
• service: notify.mobile_app_your_device metadata: {} data: title: Spa Needs Attention message: Check Spa mode: single'

Tip from a Pro: If you have trouble with reliability then: round up gap and reset by 10-20% to allow more margin in the timings. Then maybe drop tolerance to accept the widest range of timings.