Star 7 Remote RF Control using CC1101

This is a simple repo containing code to send RF commands to Star (https://star.co.il/) fans using a basic CC1101 Transceiver (python-cc1101) wired to a Raspberry PI

RF Protocol

The RF communication was recorded using URH. Each remote got a few switches near the battery place that allows to change the remote "identifier", so several fans in proximity can be controlled by different remotes.

Since I had two different remotes it was rather easy to parse the control packets -

• The remote baud rate is ~3300 (~300µs per symbol)
• Each bit got a carrier 10 bits - so 1101 is transmitted as 101101100101
• The first 5 bits corresponds to the "identifier switches"
• The last 8 bits are the command
• Long-pressing a button just keeps transmitting the same packet repeatedly

RF Commands Table

Command	HEX
Power	0x84
Light	0x82
Speed 1	0x90
Speed 2	0x94
Speed 3	0xa0
Speed 4	0xb0
Speed 5	0xc4
Speed 6	0xc0

Using CC1101 to control the fan

After understanding the RF protocol we can use CC1101 (or any other RF transmitter/transceiver) to control the fans. Check control_fan.py for more information.

Exposing API and wiring to Home Assistant

Python Setup + Running Flask

sudo apt install python3.11
python -m venv /home/pi/python-env
source /home/pi/python-env/bin/activate
pip3 install -r requirements.txt
flask --app app run --host=0.0.0.0 # (or gunicorn -w 2 app:app)

Flask and Gunicorn

A very simple flask application is included in app.py which exposes /control/<fan_id>/<command>.

A basic .service file is included to serve the app using Gunicorn.

Home Assistant Fan Template

Once you have the service running on your raspberry pi you can use the following configuration to wire the API to a fan template (add to your configuration.yaml) - don't forget to correctly set YOUR_RASPBERRY_PI_ADDRESS

rest_command:
  fan_control:
    url: "http://<YOUR_RASPBERRY_PI_ADDRESS>:5003/control/{{fan_id}}/{{command}}"
    method: GET
    content_type: "application/x-www-form-urlencoded; charset=utf-8"

# Keep track of the fan state
input_boolean:
  bedroom_fan_state:

# Keep track of fan speed
input_number:
  bedroom_fan_percentage:
    name: Bedroom Fan Percentage
    min: 0
    max: 100

fan:
  - platform: template
    fans:
      bedroom_fan:
        friendly_name: "Bedroom Fan"
        unique_id: bedroom_fan
        value_template: "{{ states('input_boolean.bedroom_fan_state') }}"
        percentage_template: >
          {{ states('input_number.bedroom_fan_percentage') }}
        turn_on:
          - service: rest_command.fan_control
            data:
              command: "speed3"
              fan_id: "28"
          - service: input_boolean.turn_on
            target:
              entity_id: input_boolean.bedroom_fan_state
          - service: input_number.set_value
            target:
              entity_id: input_number.bedroom_fan_percentage
            data:
              value: 50
        turn_off:
          - service: rest_command.fan_control
            data:
              command: "power"
              fan_id: "28"
          - service: input_number.set_value
            target:
              entity_id: input_number.bedroom_fan_percentage
            data:
              value: 0
          - service: input_boolean.turn_off
            target:
              entity_id: input_boolean.bedroom_fan_state
        set_percentage:
          - service: rest_command.fan_control
            data_template:
              command: >
                {% if percentage < 17 %} speed1
                {% elif percentage < 34 %} speed2
                {% elif percentage < 51 %} speed3
                {% elif percentage < 67 %} speed4
                {% elif percentage < 84 %} speed5
                {% else %} speed6
                {% endif %}
              fan_id: "28"
          - service: input_number.set_value
            target:
              entity_id: input_number.bedroom_fan_percentage
            data:
              value: "{{ percentage }}"
        speed_count: 6

If All Goes Well

You should have a fan entity, possibily exposed to HomeKit as well!