Network LED Strip Control for Raspberry Pi

A Python implementation of a server and client for controlling addressable SK6812 LED strips

Usage

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Dependencies

rpi-ws281x-python is required on the Pi running the server.

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Hardware Setup

• Runs on any model of RasPi
• Requires a 5V power supply for the strip
• Connect pins correctly:
  1. Power supply ground to strip ground
  2. Pi ground to strip ground
  3. Power supply +5v to strip +5v
  4. Pi GPIO18 to strip data in

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Software Setup

Place the server.py file in any folder on the Pi, and place runOnServerStart.py and networkLightControlClient.py in the same directory. Place lightStripServer.service in /etc/systemd/system/ and in the file, change PATH_TO_SERVER.PY on line 9 to the path to where you put server.py. To start or stop the server, run sudo systemctl start lightStripServer.service or sudo systemctl stop lightStripServer.service, respectively. To set the server to run on startup, run sudo systemctl enable lightStripServer.service.

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Client API Usage

To import, simply import networkControlledStrip from networkLightControlClient. networkLightControlClient.py must be in the same directory as the program.

from networkLightControlClient import networkControlledStrip

Initialisation

Initalise a connection to the server by initialising a networkControlledStrip object

strip = networkControlledStrip(ip, port)

Parameters:

• ip: String - The IP to connect to
• port: Integer - The port to connect to, defaults to 1337

Returns:

• networkControlledStrip object

Throws:

• If a connection to the server cannot be established, the respective network exception is thrown.

Method setPixelColour(LED_ID, w, r, g, b)

Sets the specified LED to the specified colour. This function does not take effect immediately, it stores changes to the strip which are then pushed with send().

Parameters:

• LED_ID: Integer - The ID of the LED to set the colour of. Counts from 0, starts at the start of the strip and enumerates.
• w: Integer - The brightness to set the white channel to. Accepts values 0-255 inclusive.
• r: Integer - The brightness to set the red channel to. Accepts values 0-255 inclusive.
• g: Integer - The brightness to set the green channel to. Accepts values 0-255 inclusive.
• b: Integer - The brightness to set the blue channel to. Accepts values 0-255 inclusive.

Returns:

• 0 If the operation was successful.
• -1 If the operation failed.

Method setAllPixels(w, r, g, b)

Sets all LEDs in the strip to the specified colour. This function also does not take effect immediately, rather buffering it's changes to be sent in one go with send().

Parameters:

• w: Integer - The brightness to set the white channel to. Accepts values 0-255 inclusive.
• r: Integer - The brightness to set the red channel to. Accepts values 0-255 inclusive.
• g: Integer - The brightness to set the green channel to. Accepts values 0-255 inclusive.
• b: Integer - The brightness to set the blue channel to. Accepts values 0-255 inclusive.

Returns:

• Nothing.

Method send()

Sends all buffered changes to the server in a single message.

Parameters:

• None.

Returns:

• 0 If the operation was successful.
• -1 If the operation failed due to Timeout, Connection Reset or Broken Pipe.

Throws:

• If any other exception is thrown by attempting to send the message, that exception is not handled

Method disconnect()

Disconnects from the server. If the disconnect message fails to get to the server due to Connection Reset or Broken Pipe, the exception is caught and treated as a disconnection anyway.

Parameters:

• None.

Returns:

• Nothing.

Throws:

• If the message fails to reach the server for a reason other than Connection Reset or Broken Pipe.

Property LED_COUNT

A property of the networkControlledStrip object that represents the number of LEDs in the strip.

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Examples

Set every other LED to red:

for i in range(strip.LED_COUNT):
    if i%2 == 0:
        strip.setPixelColour(i, 0, 255, 0, 0)
strip.send()