Wednesday, March 25, 2009

PS/2 Keyboard driven Morse code Generator

This is simple PIC microcontroller base project to generate Morse codes using standard PS/2 keyboard. This project based on Microchip’s PIC16F73 microcontroller and National semiconductor’s LM386 audio power amplifier. Software for PIC microcontroller is written using MikroC and all the source codes, schematic diagrams and other documents are available to download at here.


In this project we choose PIC16F73 because of it’s 4KW (KWords) program memory, it is possible to replace this MCU with any suitable MCU which having 4KW (or more) flash memory. (For example Atmel AT89C4051-24SJ with different source code, Microchip PIC16F648 with some minor changes in source code, etc)

Audio power amplifier of this project is based on National Semiconductor’s LM386. We choose LM386 because of its lower power consumption and compactness. User may also replace this module with suitable power amplifier (for example Philips TDA7052, TDA8551, National’s LM4906, etc.)

PIC16F73 software is developed using MikroC 8.1 compiler.

Tuesday, March 17, 2009

User Programmable Automatic Night Light

In this project we developed user programmable automatic night light using Microchip's 8bit MCU – PIC12F675. In this design user may be able to program and store the time duration of the master light. Compared with other designs this circuit use transformerless power supply, and TRIAC to control the master light.

Complete MCU software source code, operating guides and circuit diagram of this project is available to download at here.

To get more information about transformerless power supply please refer the Microchip application note AN954, and ST application note AN438 for MCU and TRIAC interfacing.