Clojure library for max7219 led matrix driver (on raspberry pi).
The max7219 is serial interfaced 8x8 (or 7 segment) LED driver. Several drivers can be chained in series. You use the driver by sending it a command and data (1 byte + 1 byte) over SPI. Each driver hold 2 bytes, and will shift out the old values to the next device in the chain. The driver will execute the command it holds when slave select is set high at the end of transmission.
The 8x8 matrix display is arranged by 8 columns, each column is represented by 1 byte (8 bit). This means you can update 1 column on every display for every round of transmition.
[1 255 1 255] you turn all leds in
the first column on for two displays.
[1 255 2 0] turns all leds on
in the first column on the second display, and turns all leds off on
the second column for the first display (commands are shifted to the next
display if a new byte pair is received).
More information with examples available in this blog post.
Copyright © 2014 FIXME
Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.