Hardware Reference
In-Depth Information
This indicates which LEDs to turn on. The first byte is for the first column of
green
LEDs. In this case, all are turned off. The next byte is for the first column of
red
LEDs. The hex
0x3c
number is
0b00111100
in binary. This means the first two
red LEDs are off, the next four are on, and the last two are off. The next byte
(
0x00
) says the second column of
green
LEDs are all off, the fourth byte (
0x42
=
0b01000010
) says just two
red
LEDs are on, and so on. Declarations define four
different patterns to display on the LED matrix, the last being all turned off.
Open the I
2
C port.
Send three commands to the matrix to get it ready to display.
Now, we are ready to display the various patterns. After each pattern is displayed,
we sleep a certain amount of time so that the pattern can be seen.
Finally, send commands to the LED matrix to set the brightness. This makes the
disply fade out and back in again.
