October 27, 2009
AVR homebrew device with iPhone aspirations
Can you make an iPhone out of an AVR? No. Can you get a surprising amount of functionality out of a humble 8 bit processor and a cheap touch LCD? Yes.
The iPhone runs more than 30 times faster (417Mhz ARM vs 12Mhz AVR) and has more than 30,000 times as much ram RAM (128M vs 4k) yet this frumpy little device can ape some of the iPhones neater tricks.
Hardware
320x240 LCD with 4 wire resistive touch screen - a ELT240320ATP variant from a dead Sylvania MP3 player - uses a ILI9325 controller.
12Mhz Atmega644 CPU with 64k Flash and 4k RAM - demo fits in 32k.
USB connector for PC communication and charging.
Lithium polymer battery with software controlled power.
Software controlled backlight.
SD Micro slot.
Software
LCD driver to support blitting image decompression and smooth scrolling.
Z-sorted span 3D engine with zero overdraw.
Basic UI framework for gadgets and poorly drawn pictures.
USB mouse or keyboard HID support.
Sampling profiler.
Movie playback.
Sprite engine
http://rossum.posterous.com/avr-homebrew-device-with-iphone-aspirations 
