RFBRIDGE module (rfbridge.cpp), originally created for the Itead Sonoff RF Bridge.

Since version 1.14.0, combined with RF module and now allows to use standalone ESP8266 board with an external RF receiver / transmitter

Since version 1.15.0, underlying RF transmitter / receiver library was changed to the version used by OpenMQTTGateway in GATEWAY_RF configuration.

rfin and rfout topics are used to receive and send messages. rfraw topic allows to send raw binary messages to the EFM8 chip ⁽²⁾

The RF codes produced by the firmware for the "direct" modified board are different from the ones produced by the "vanilla" bridge for same remote. This was a design choice, due to the different kind of information passed by the EFM8BB1 hardware and the software library.

For example, running mosquitto_sub -v -t "+/rfin":

rfbridge-vanilla/rfin 2F260186046ACE9778
rfbridge-direct/rfin C001018418CE9778

Thanks to @pelson, here is an example of how to port basic Arduino sketch code that uses RCSwitch to send messages using MQTT ³:

mySwitch.setProtocol(4);
mySwitch.send(2175276, 24);

Equivalent message for the rfout would be:

mosquitto_pub -t "rfbridge-direct/rfout/set" -m "C00400001821312C"

• C0: The initial byte (always the same)
• 04: Protocol 4.
• 0000: 2 timing bytes (16 bit int?) - I wanted the timing to be defined by the protocol, not overridden.
• 18: Bit length (24 in decimal)
• 21312C: The code to send (2175276 in decimal), exactly 3 bytes.

Notice that we omit the leading zeroes. This might not always be the case and depends on the value of 'Bit length'. For example, in case of Bit lenght equal to 19, we would need 4 bytes. Similarly, for 11 we would need only 2.

To configure RFBridge as a sensor.espurna_123456_rfin sensor entity:

- platform: mqtt
  name: "ESPURNA 123456 RFIN"
  state_topic: "ESPURNA-123456/rfin"
  availability_topic: "ESPURNA-123456/status"
  payload_available: "1"
  payload_not_available: "0"
  force_update: true
  expire_after: 1

Most of the time we are only interested in the last 3 bytes. It is possible to modify the incoming data right in the sensor configuration by using the value_template attribute ^{4 5}

  value_template: >
       {% if not value %}
           "No data"
       {% endif %}
       {{ value[-6:] }}

Or, with mqttUseJson => "1":

  state_topic: "ESPURNA-123456/data"
  value_template: {{ value_json["rfin"] }}

⁽¹⁾ Triggers a learn action. The index after the "learn" magnitude indicates the relay the code will be linked to. The payload of the message is the relay ID (before the comma) and the action (0 for off, 1 for on).

⁽²⁾ Raw codes requires a special firmware in the EFM8BB1. See Portisch/RF-Bridge-EFM8BB1 and issue #386 for more information. Full list of commands: https://github.com/Portisch/RF-Bridge-EFM8BB1/wiki/Commands

⁽³⁾ https://gitter.im/tinkerman-cat/espurna?at=5d39a15be16c666d8967d6c9

⁽⁴⁾ https://www.home-assistant.io/docs/configuration/templating/

⁽⁵⁾ https://jinja.palletsprojects.com/en/master/templates/