My External Board

Update History :
01/02/2003 : some information added
Created on 01/01/2003

1: Test Board
This is my external control board for the test purpose. This consists of four push switch, two toggle switch and one rotary encoder with push switch.　The diode is using 1S1588.
Push and toggle switch are work well. However rotary encoder is not working. I can not set the function to the rotary encoder using MCP's utility.

(01/02/2003)
Flat cable for connection between MCP unit and Test Board must be less than 30cm ( 12 inch).
If it is 30cm or more, the 7 segment LED of the MCP unit will not be displayed correctly.
I think TTL Buffer such as SN74LS245 should be used to LED serial data output (3 lines) for cable extension.

Schematic : My-Ext-Board-Sch.PDF (8KB)

2: LED and LED Driver Board
In the MCP-747, MAX7219 of MAXIM is used for driver of the 7-segment LED.
I made the simple driver board for the 7 segment LED.
In the MCP-747, three MAX7219s are connected as a serial.
Therefore, I made three units.

LED Borad : solder side
Schematic : my-led-board.pdf (10KB)

LEDs are assembled

MAX7219 Driver Board : Solder Side
Schematic : my-led-driver.pdf (6KB)

MAX7219 Driver Board : Parts side (IC is not mounted yet)

To be continued.