Record any replay any RF signal. (optional) Integrate with Home Assistant. Trigger replay with Alexa or Google Home.
Common use cases: airconditioners, remote power plugs, fans, shades and kitchen hoods. This won't work with rolling codes often used for more secure communication to open doors for example.

• Raspberry Pi
• radio receiver USB dongle (RTL-SDR with RTL2832U chipset)

on your Pi

1. Install Raspberry Pi OS.
2. Install https://github.com/F5OEO/rpitx
3. Connect the RTL-SDR dongle to your Pi.
4. Record remote signal.

To find the frequency, your can install SDR software. If the remote has an FCC id, you can look that up here. Common frequencies are: 433.92, 868.3, 315, 288, 300, 303, 306, 310, 318, 330, 390, 403.55 and 418 MHz.

cd rpitx
# this records on 868.00 MHz frequency and writes it to a fan-on-button.iq file
rtl_sdr -s 250000 -g 35 -f 868.0000e6 fan-on-button.iq

      above can also be done through the rtlmenu.sh GUI

5. CTRL + C to stop recording.

You can remove the RTL-SDR dongle when you're done recoding. It's not required for sending.

6. Add electrical wire to GPIO pin#7 (4th pin down, left row) - see picture.
7. Replay recording.

sudo ./rpitx/sendiq -s 250000 -f 868.0000e6 -t u8 -i ./rpitx/fan-on-button.iq

If you don't have HA, start here.

Create a command line switch for everyone recording you want to replay.

# configuration.yaml
command_line:
  - switch:
      name: fan_on
      unique_id: fan_on
# ssh is only required if HA and rpitx run on different machines
      command_on: "ssh -i /config/id_rsa -o StrictHostKeyChecking=no -q pi@<YOUR.PI.IP.ADDRESS> sudo ./rpitx/sendiq -s 250000 -f 868.0000e6 -t u8 -i ./rpitx/fan-all-on.iq"
      command_off: off
# HA doesn't get feedback if the device is on or off.  This returns the switch always back to the off-state.  
      command_state: off

This will allow Alexa to see the switch as a Philips Hue light.

# configuration.yaml
emulated_hue:
  listen_port: 80
  expose_by_default: false
  entities:
    switch.fan_on:
      name: "fan on"
      hidden: false

Alexa gets confused if you create multiple devices with simular names.
To work around this, create Alexa Routines with a unique trigger sentences and avoid the words 'on' or 'off'.
I used start- and stop cooking - see example.

This will allow you to remotely trigger the switch via an HTTP POST request.
Can be used with Google Home for example.

# configuration.yaml
automation:
  - alias: webhook_fan_on
    trigger:
    - platform: webhook
      webhook_id: <PICK-A-RANDOM-WEBHOOK-ID>
      allowed_methods:
        - POST
        - PUT
      local_only: false
    condition: []
    action:
    - data: {}
      entity_id: switch.fan_on
      service: switch.turn_on
    mode: single

Test the webhook

curl -X POST https://<YOUR-HA>.duckdns.org/api/webhook/<YOUR-WEBHOOK-ID>

Only required if HA and rpitx run on different machines.
The certificate allows to remote execute ssh commands on another machine without a password prompt.

create certificate

ssh-keygen -t rsa -b 4096

send certificate to your pi (command still run on HA)

ssh-copy-id pi@<YOUR.PI.IP.ADDRESS>

Initially, HA gave errors when running the remote ssh commands. I can't remember the exact fix. It was either the HA user context not having access to the key files or the file and folder permissions for the certificate keys were not set correctly. I think below two things fixed it. Let me know if this works for you.

on HA copy the id_rsa to the HA /config folder

on your Pi

chmod 700 ~/.ssh/
chmod 600 ~/.ssh/*

If you don't have HA, you can try creating webhooks with https://github.com/ncarlier/webhookd.
Protecting this setup is beyond the scope of this repository. It's not a question if you get hacked, but when.
Consider using an nginx proxy, Let's Encrypt and Duck DNS.

All rights of the original authors reserved.

Creative Commons Zero v1.0 Universal license