UNIHIKER, NFC, and LEDs: A Story of Interaction and Color

from pinpong.board import Board, Pin, NeoPixel
from flask import Flask, jsonify


COLORS: dict = {
    'red': (255, 0, 0),
    'green': (0, 255, 0),
    'blue': (0, 0, 255),
    'black': (0, 0, 0),
    'white': (255, 255, 255)
}


app = Flask(__name__)

@app.route(rule='/api/colors', methods=['GET'])
def get_available_colors():
    """
    This method is an API route that returns the available colors. The values are from the COLORS dictionary.

    :return: A JSON object containing the status and the available colors.
    """
    return jsonify({'status': 'success',
                    'message': COLORS}), 200

@app.route(rule='/api/<string:color>', methods=['GET'])
def set_color(color):
    """
    This method is an API route that sets the color of an LED strip. It takes in a color parameter as a string and
    returns a JSON response indicating the status and message. The color parameter is used to set the color of each
    LED in the strip. It is expected to be a valid color value that matches one of the predefined colors in the COLORS
    dictionary. If the provided color is valid, the method iterates through each LED in the strip and sets the color to
    the corresponding value from the COLORS dictionary.

    The method returns a success response with a status code of 200 and a message indicating the color that was set if
    the provided color is valid. If the provided color is not valid, the method returns an error response with a
    status code of 400 and a message indicating that the color is not valid.

    :param color: The color value to set for the LED strip.
    :return: Response indicating the status and message.
    """
    global led

    api_color = str(color.lower())

    if api_color in COLORS:
        for pixel in range(led.num):
            led[pixel] = COLORS[api_color]

        return jsonify({'status': 'success',
                        'message': f"{color} is valid."}), 200
    else:
        return jsonify({'status': 'error',
                        'message': f"{color} is not valid."}), 400


if __name__ == '__main__':
    Board().begin()

    try:
        led = NeoPixel(Pin(Pin.P24), 12)
        led.clear()
    except Exception as err:
        print(err)

    app.run(host='0.0.0.0')

```bash
# upload script with SCP
scp -r ~/NeoPixelAPI [email protected]:/root/NeoPixelAPI

# login with SSH
ssh -C4 [email protected]

# change directory
cd ~/NeoPixelAPI
```

```bash
# run simple Flask server
python3 main.py 

  ___________________________
 |                           |
 |      PinPong v0.5.1       |
 |    Designed by DFRobot    |
 |___________________________|
 
[01] Python3.7.3 Linux-4.4.143-67-rockchip-g01bbbc5d1312-aarch64-with-debian-10.13 Board: UNIHIKER
selected -> board: UNIHIKER serial: /dev/ttyS3
[10] Opening /dev/ttyS3
[32] Firmata ID: 3.7
[22] Arduino compatible device found and connected to /dev/ttyS3
[40] Retrieving analog map...
[42] Auto-discovery complete. Found 30 Digital Pins and 30 Analog Pins
------------------------------
All right. PinPong go...
------------------------------
 * Serving Flask app 'main' (lazy loading)
 * Environment: production
   WARNING: This is a development server. Do not use it in a production deployment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on all addresses.
   WARNING: This is a development server. Do not use it in a production deployment.
 * Running on http://10.0.0.14:5000/ (Press CTRL+C to quit)
```

### Example usage:

```
GET http://[IP address]/api/colors
Response:
{
    "message":{
        "black":[0,0,0],
        "blue":[0,0,255],
        "green":[0,255,0],
        "red":[255,0,0],
        "white":[255,255,255]
    },
    "status":"success"
}

GET http://[IP address]/api/red
Response:
{
    "status": "success",
    "message": "red is valid."
}

GET http://[IP address]/api/black
Response:
{
    "status": "success",
    "message": "black is valid."
}

GET http://[IP address]/api/invalid_color
Response:
{
    "status": "error",
    "message": "invalid_color is not valid."
}
```