PIC based small thermometer with USB interface

Device is more experimental and tend to be used to measure indoor and outdoor temperature. It uses PIC 18F2550 microcontroller with built in USB peripheral. Microcontroller reads sensor (TC1047A ) data and sends it via USB to PC.   USB firmware is taken from Microchip, so not a big knowledge of USB specific software is required. Hex file and other project details are available for download. Author left possibility to connect other sensors (humidity, pressure) to board and syndicate it to the web with Google earth information. Continue reading

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

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