My plan is to build a scalable LED matrix screen. My plan is to create
a small base board where a matrix is plugged in, the board has a serial
shift register that controls the columns. These matrix boards each form
one line of the screen, where the left side of the line will have the
controller board, and the other side the driver board. These lines of
screen can again be combined vertically to make a complete screen.
<general overview picture>
Column driver
The line driver board is a backing for the led matrix, some decoupling
and a TPIC6B595
high current sink shift register.
Led board bottom
Led board Top:
Line driver
The column driver sources the current for the lines of the screen. The
current is sourced by FZT953
PNP switching transistors by zetex. The transistors are controlled by a
TPIC6B595 high current sink shift register.
Driver board Bottom:
Driver board Top:
Controller board
The controller board accepts commands from the serial port and updates
the "framebuffer" for that current part of the screen. If the
coordinates are not for that part of the screen, it is forwarded to the
next part.
The microcontroller used for the controller board is a ATmega88. The
UART is used for PC side communication while the SPI bus is used to
output data to the shift registers of the current line.
