1-Wire Temperature Control

Controller Algoritam Controller Setup List of Components

The 1-Wire Temperature Controller has a two line x 16 LCD display and four push buttons - ESC, UP, DOWN, ENTER.The push buttons and the LCD display are used to set and monitor the controller parameters. The action of each push button depends from the menu position. The parameters can be easily set using a personal computer as well.For more details see the interface application.The controller parameters are stored in the EEPROM of the PIC16F628A. In the following tables, all parameters are introduced in the display sequence.

Parameter Description:

Parameter	Description	Range	Default
PVar	Process temperature value	-55.0°C to +125.0°C	-
SPoint	Desired temperature value of the process	-55.0°C to +125.0°C	25.0°C
Control	Control type	HEATING or COOLING	HEATING
Bandwidth	Prevents the output relay from chattering	0.0°C to +12.0°C	1.0°C
Output Delay	Delay of the timer function.	0s to 59s	0s
Startup mode	Mode of the controller when power-up	AUTO, MANUAL, PREVIOUS	PREVIOUS

Controller Menus and Push-button Actions:

LCD DISPLAY	PUSH BUTTON ACTION	LCD DISPLAY	PUSH BUTTON ACTION
	ESC - switches between Auto and Manual mode ENTER - changes the output relay ( ON or OFF ) in manual mode DOWN - scrolls to SP Menu UP - does nothing
	ESC - switches between Auto and Manual mode ENTER - goes to SPoint new value display UP - scrolls to Pvar menu DOWN - scrolls to Deadband menu		ESC - exits without saving ENTER - saves SPoint in EEPROM and exit DOWN - decreases SPoint UP - increases SPoint
	ESC - switches between Auto and Manual mode ENTER - goes to Deadband new value display UP - scrolls to Deadband menu DOWN - scrolls to Control menu		ESC - exits without saving ENTER - saves Deadband in EEPROM and exit DOWN - decreases Deadband UP - increases Deadband
	ESC - switches between Auto and Manual mode ENTER - goes to Celect control method display UP - scrolls to Deadband menu DOWN - scrolls to Output Delay menu		ESC - exits without saving ENTER - saves Control method in EEPROM and exit DOWN - sets control method to COOLING UP - sets control method to HEATING
	ESC - switches between Auto and Manual mode ENTER - goes to Output Delay new value display DOWN - scrolls to Startup Mode menu UP - scrolls to Control Menu		ESC - exits without saving ENTER - saves Output Delay in EEPROM and exit DOWN -decreases Output Delay UP - increases Output Delay
	ESC - switches between Auto and Manual mode ENTER - goes to Select ( initial ) startup mode display DOWN - scrolls to Output Delay UP - does nothing		ESC - exits without saving ENTER - saves Startup mode in EEPROM and exit DOWN - scrolls to Auto mode at startup DOWN - scrolls to Previos mode at startup

Security function:

When pins 2 & 7 are opened and pins 1 & 8 are closed, the PVar display is accessed only.See the position of the DIP switch SW1 on the Circuit Diagram page.