BlastIR ESP8266 IR Repeater

BlastIR is a dead-simple infra-red repeater using MQTT and the ESP8266.

Record transmitted IR commands by subscribing to ir/<repeater>/recv and transmit commands by publishing to ir/<repeater>/send

Setting up a Repeater

BlastIR uses PlatformIO, so make sure you have VS Code and the PlatformIO extension installed.

1. Download a copy of the BlastIR repository
2. Edit credentials.h to include your WiFi and MQTT details
3. Connect a WEMOS D1 Mini and use the PlatformIO: Upload command to program the board
4. Wire the board up according to the schematic below

Schematic

Recording IR Commands

Subscribe to the MQTT topic you specified in credentials.h and use your remote to transmit the desired command while pointed at the repeater.

Example:

> mosquitto_sub -h 172.23.1.3 -p 1883 -u <user> -P "<pass>" -t 'ir/heatpump/recv'

<send command using remote>
ir/heatpump/recv 4357 4422 476 1626 534 1652 503 ...

Sending IR Commands

To send an IR command, publish data that you recorded earlier to the MQTT topic specified in credentials.h.

Example:

> mosquitto_pub -h 172.23.1.3 -p 1883 -u <user> -P "<pass>" -t "ir/heatpump/send" -m "4357 4422 476 1626 534 1652 503 ..."

Home Assistant Example

You can transmit IR commands using a Home Assistant automation similar to the following:

#
# Transmit an IR OFF signal whenever the heatpump is supposed to turn off
#
- alias: Turn Heatpump Off
  trigger:
    - platform: state
      entity_id: input_boolean.heatpump_should_run
      to: 'off'
  action:
    - service: mqtt.publish
      data:
        topic: "ir/heatpump/send"
        payload: "4400 4400 560 1600 ..."
        qos: 2

Cleaning up Received Data

The output timing of the TSOP4138 can be a bit variable and result in mark/space times with a lot of jitter. If required, you can adjust each duration to match a standard set of durations using the following Python script:

expected_durations = [ 560, 1600, 4400 ]
durations = "4357 4422 476 1626 534 1652 503 ..."
durations = [ int(d) for d in durations.split() ]
durations = [ min(expected_durations, key = lambda usec: abs(d-usec)) for d in durations ]
durations = [ str(d) for d in durations ]

print(" ".join(durations))