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Raspberry Pi - Heart beat - 8x8 LED display with I2C BackPack from AdaFruit

5 February 2015

This is based on the AdaFruit 8x8 Bicolor LED display with I2C BackPack. It's connected to a Raspberry Pi 2, although it's only very simple and could be connected to any model Raspberry Pi.

After soldering the parts together (checking that the display is the right way round - with the writing near the round marker) then connect to +5v (or if using other I2C may need to use 3V3) Gnd and ports 3 and 5 for the I2C connection.

Enable I2C through the raspi-config interface

Install smbus python package

sudo apt-get install smbus

Get the AdaFruit source code:
git clone https://github.com/adafruit/Adafruit-Raspberry-Pi-Python-Code.git

I then put together the following code (which is only a quick hack): 

#!/usr/bin/python

import time
import datetime
from Adafruit_8x8 import ColorEightByEight

grid = ColorEightByEight(address=0x70)

# This is a bicolour LED - setting the pixel to 0 is off, 2 is red, 3 is yellow.
red = 2

heart1=[0b00000000, 0b01100110, 0b10011001, 0b10000001, 0b01000010, 0b00100100, 0b00011000, 0b00000000]
heart2=[0b00000000, 0b01100110, 0b11111111, 0b11111111, 0b01111110, 0b00111100, 0b00011000, 0b00000000]

while(True):

  for y in range(0, 8):
    position = 128
    for x in range(0, 8):
      value = position & heart1[y]
      if (value > 0):
        value = red
      grid.setPixel(x, y, value )
      position = position >> 1

  time.sleep(0.5)

  for y in range(0, 8):
    position = 128
    for x in range(0, 8):
      value = position & heart2[y]
      if (value > 0):
        value = red
      grid.setPixel(x, y, value )
      position = position >> 1

  time.sleep(1)

Raspberry Pi - Heart using Adafruit 8x8 LED matrix with LED Backpack