A DIY ATMega32 Prototype Board

Overview

AVR micro-controller is a popular embedded controller for electronic students, engineers and hobbyists. Making a PCB for for micro-controller is exiting stuff for novice electronic practicing. It's is hard at first time but we can easily use it for firmware and circuit testing for later on.

 

I have some components I left a long time ago. So I designed my own test board for 40-pin AVR microcontrollers. I have ATMega644, ATMega32 and ATMega16 in my project box. I also have some USB PIC microcontroller, PIC18F2550. It can be use to make a DIY PICKit2 programmer that able to program any AVR microcontroller using AVRdude IDE. This software is very user-friendly. 

Some AVR micro-controller users prefer a USBasp or an FTDI chip with AVRdude to program this these chips. But currently I don't have them at my workshop. 

Schematic 

I use Protues VSM since it's easy to use for circuit and PCB design. I put some blocks on this board,

1. A PICKit2 programmer and AVR ISP header
2. A On-board 12VDC to 5VDC regulator
3. A RS-232 to TTL converter
4. A Reset button and external crystal oscillator
5. Three buttons for ATMega32 external interrupts
6. LED(s) with DIP switch connects to PORTC
7. SPI header
8. Two potentiometers for ADC input
9. DIP switch for ADC configuration
10. A DS1207 I2C RTC 
11. A  40-pin ZIF socket for ATMega32, ATMega16, etc.

 The pictures below are its circuit diagram.

Schematic Sheet #1

Schematic Sheet #2

Schematic Sheet #3

 It contains three A4-size sheets.

Printed Circuit Board (PCB)

This PCB is quite large (173.7 x 111.2mm(6.84 x 4.38 inches). We can fabricate it by hand using a simple tone transfer paper method because it contain a dozen of wire jumpers on top copper layer.

Top Copper Layer

Bottom Copper Layer

 I you prefer a simple tone transfer method, use the patterns below.

Top Copper Layer

Bottom Copper Layer

Top Silk Layer

Bottom Resist Layer

 Some PCB fabrication could fabricate it for around 40USD.

However I made the earlier version of this board by hand using a simple toner transfer method and and FR-4 copper clad board. I use ferric chloride acid to etch the copper clad. It's very low cost and fast. 

 

 Click here to download this PCB project.