Light Module
This module provides a matrix of LEDs in an 8x8 pattern. Each light can be individually controlled.
Hardware Specifications
The module is using a MAX7221 chip for addressing the individual LEDs. It is driven directly from the mainbord and uses SPI (Serial Peripheral Interface) for communication.
Pinout
Pin Number | Name | Description |
---|---|---|
10 | CS | Tells the MAX7221 that it should pay attention to the data being sent. When this pin is low, the device is selected and communication can occur. When it is high, the device ignores the SPI bus. |
11 | DIN | This pin is used for sending data from the mainboard to the light module. In SPI terminology, this is also known as MOSI (Master Out Slave In). |
12 | CLK | This pin provides the clock signal generated by the mainboard. |
Usage
In order to be able to interface with the MAX7221 controller, we have to import a library. Add the following to your platformio.ini
:
This adds the MD_MAX72XX
library for accessing the MAX7221 chip. The following example lights up the LED at coordinates (0,0)
: