Three channel fan speed controller for PC

Jos van Eijndhoven have constructed simple but effective PC fan speed controller. He used PIC 16F676 microcontroller to read temperature sensors and provide PWM for three independent channels. Potentiometers control fan start temperature for each fan.     The controller is programmed linearly to increase fan speed when temperature increases and decrease fan speed slowly even if temperature drops fast, in order to avoid instability in control. In Schematic he used switching power MOSFETs BUZ72 to control speed of fans with PWM and LM60 temperature controllers. Also there are ability to connect several fans in parallel to one channel if needed. Code is written in C and compiled to hex with CC5x compiler. Continue reading

Digital thermometer DS1820 on PIC16F84

This is very simple design which can be built by everyone who can solder. Device is capable to measure temperatures in range from 0 to 99ºC and display it on LCD.   Firmware is written in C language ready to be compiled with CCS C compiler. Also in source code package is compiled version of program which can be flashed immediately to PIC. Continue reading

8×8 LED animation with PIC

This is simple fun PIC project which may fir Christmas decoration. Circuit is simple – 8×8 LEDs are connected to PIC19F84 via 74HC374 buffer sharing same microcontroller port.   All you have to do is to burn firmware to se demos, or you can program your own patterns by modifying assembler program. And of course be sure to align LEDs perfectly or use 8×8 LED matrix.   Continue reading