MicroControllers

/AVR

8-bit RISC microcontrollers. You get cpu, RAM, flash, eeprom, and IO on a single chip. Down to 8 pins! Can write in assembly, C (supported by GCC), or Basic (BASCOM-AVR).

Building USB devices using a PIC

• [some basics]
• [USB microphone project]
• [IgorPlug-USB] - a USB implementation for the AVR - [homepage] [avrfreaks]

/PIC?

• Example code in C (including PID and heater control) [here]
• A phase shifted PWM algorithm [here] with PIC asm code [here]

I/O Expansion

One way to get increased inputs and outputs is to use external chips that do serial->parallel (for output) and parallel->serial (for input). You use a small number of pins on the micro to talk serial to the external chips. Some of the chips can be cascaded to get more inputs/outputs.

• Serial-input parallel-output latch: 74LS595, 74HC595
• [Mini SSC II] - 12 channel serial servo controller for $44

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• [Microcontroller Crystals]