Demand Peripherals     Robotics and Automation Made Easy

WS28: Quad WS2812 Interface

The WS28 peripheral lets you control four strings of up to 64 WS2812 style RGB(W) LEDs.

 

Hardware:

The gpio4 cards have 3.3 volt outputs which is not sufficient to drive the WS2812 LED directly. You need to add a level translator to get the output voltage up to the 4 volts required by the WS2812 LEDs. If your level translator inverts the signal you can invert the outputs of the WS2812 interface by setting the config value to 1.

 

Resources:

led : which LED string to set and its value
The first parameter is which of the four LED strings to address and the second parameter is a sequence of hex characters to write to the string. The number of hex characters must be even since LEDs have 3 or 4 bytes of LED data. Use three bytes per LED for RGB and four bytes per LED for RGBW LEDs.

config : whether to invert the output or not
Set the config value to 1 to invert all four output signals. This may be needed if you level translator inverts the signal. The power up default is to have no inversion.

 

Examples:

dpset ws28 config 1
dpset ws28 led 1 ffffffffffffffffffffffffffffffffffffffffffffffff
dpset ws28 led 4 111111111111111111111111111111111111111111111111
dpset ws28 led 4 00ff00ff00000000ff00ff00ff00000000ff00ff00ff0000