HC08 Dev Board

HC08 Development Board

A programmer and development board for the Freescale HC08 series of microcontroller including:

  • 8 I/O LEDs and switches
  • Piezo speaker
  • breakout header for microcontroller IO pins
  • built-in USB circuitry

The board was designed to be assembled by students, and used in a beginning microcontroller programming class. Primary design constraints were ease of assembly/use and price.

I used gEDA for the schematic capture and PCB layout, and using the MON08 interface described in their application note.  An FTDI USB UART chip was used to allow the use of a modern USB interface instead of a legacy serial port, and a MAX232 charge pump was used to provide the high voltage for programming.  The FTDI chip I selected was TTL compatible out-of-the-box, so that functionality of the MAX chip was not needed.