This free project was designed to measure and control temperature in the range of - 55°C to +125°C with 0.1°C accuracy.
It is based on the popular PIC16F628A microcontroller of Microchip. The microcontroller uses the 1-Wire protocol ( sometimes
known as a MicroLAN ) to communicate with a DS18B20 digital thermometer and a DS2405 addressable switch. The 1-Wire
bus requires only one data line (and ground) for communication with a central microprocessor .The PIC16F628A chip
implements several basic functions, such as an ON-OFF controller function, driving a LED display, reading and writing
all 1-Wire devices. In addition, the controller can be fully configured and monitored from any Windows 9x , ME , NT ,
2000 or XP PC via RS-232C serial port using an interface application.
An overview of the main components is shown in figure 1.
- ON-OFF control method
- Heating or cooling control is available
- Auto or Manual selections
- Two line 2x16 LCD display and four push buttons
- Front panel programming
- RS-232C serial communications interface ( 2400 Baud ) to a personal computer
- Interface application available for Windows 9x / ME / NT / 2000 / XP / Win 7
- Dallas' exclusive 1-Wire bus protocol that implements bus communication using one control signal