Typical AVR microcontroller applications are signal sensing, data acquisition, motion control, lab automation, and instrument/equipment control. Many mechanical systems, for example, have less than 10- khz bandwidth. The AVR microcontrollers, clocking at 4 to 16 MHz, can facilitate fairly extended realtime control functions. AVR microcontroller has an 8-bit RISC core with built-in programmable IO ports, multi-channel ADC and DAC, serial interface, timers and counters, and pulse-with modulation generation for motor speed control. AVR also has built-in Flash memory for storing program and SRAM for run-time data store. Software/Hardware Codesign process with AVRStudio, HW development board, and external interface hardware are discussed in this paper.