Traffic Light

Rasperry Pi / 4 channel relay / LED Traffic Light / HTML

Screenshot of the HTML view (iphone)

The setup

This application uses Python flask and the GPIOs of the Rasperry Pi. The following items must be installed if this is not already the case.

pip install flask
pip install RPi.GPIO

The channel setup is defined in the "app.py" by the signals array. A signal is instantiated for each channel of the relay.
The signal class requires the following parameters:

• GPIO pin (for control)
• Name (this is the name of the button in the HTML view)
• Color (the color of the button in the HTML view)

signals = [
    Signal(21, "red", "#ff0000"),
    Signal(12, "orange", "#ffa500"),
    Signal(16, "green", "#008000")
]

Any number of signals can be added to the array, the view and control is dynamic and will display and use this. This project also works with a 1 or 8 channel relay.

Since I am controlling a traffic light, I have used the colors and names for the corresponding traffic light colors in my example.