AVR Microcontroller Board

Microcontroller with Integrated Programmer

Why did I do it?

I have purchased many microcontroller boards in the past, but none of them suited my needs very well, so I decided to have a go at designing one myself. My design goals were really quite simple. I wanted a board which was inexpensive, powerful, easy to program and easy to interface.

In System Programming

I wanted my board to be easily programmed, and re-programmed in system. Initially I considered using an 8052 derivative chip, but I really started to like the Atmel AVR and I realized that I could include the ISP feature that I wanted for very little expense and very little circuit board real estate. The reason that the ISP feature could be added so economically was because Atmel make another small yet powerful microcontroller, the AT89C2051. It handles the interface between the computer and the AVR device. Unfortunately it cannot be programmed via the SPI bus like the AT90S1200, so it cannot be a target controller on this board.

The Bus

Initially I was going to make a dual row bus, like almost every other microcontroller I have seen. While trying to implement that type of bus I realized that a single row bus would be easier to interface to hobbyist boards and would plug directly into prototype breadboards. I have found that this bus is very easy to interface to the various projects I am working on.