Here is my home-made kit of ATmega32 microcontroller interfacing. The ATmega32 controller is rich with features like onboard 32kB in-System programmable flash, 1 KB EEPROM, 2KB SRAM, 10bit ADC (8 channel), SPI bus inteface, TWI (compatible with I2C bus) interface, an USART, analog comparator, etc. That’s why I’ve selected it to load my kit with all those features.
This M32 card is having an LCD inteface with contrast adjustment, an RS232 port for connecting with PC, a connector for 8 analog voltage inputs to measure by ADC, a Real Time Clock IC DS1307 from maxim with battery back-up, four general purpose keys, two keys for generating interrupts and an LED.
The circuit can be powered by an easily available 12v DC adapter. The voltage regulator IC 7805 used to convert the input into regulated 5v supply.
See below the kit in powered on condition and the schematic (click to enlarge the images)
The PCB is completely home-made, using the etching technique with the Ferric Chloride chemical. If you want to know how to make a PCB yourself from your layout, visit following webpage, it’s really helpful:
The schematic and layout of the M32_card shown here are prepared using EAGLE. It’s a single layer board for making the home-preparation easy. Check out the bottom layer and the layouts in the pics below:
For more details click : Make-Yourself ATmega32 Starter’s Kit with LCD, I2C, SPI, RTC, ADC interfaces