The use of ADCs and LCDs is demonstrated in this project which aims to produce a simple temperature alarm based on a PIC16C84 microcontroller.
This temperature alarm uses a 2-line LCD display where the current temperature is shown in both Celcius and Fahrenheit degrees. The user is allowed to set independent high and low temperature alarm points by featuring a 3-key keypad. The minimum and maximum temperatures encountered is also recorded by the alarm. The design of the unit makes it configurable by the use to function either as a temperature alarm or a thermostat with the difference of producing intermittent beep when a limit is exceeded if used as alarm.
The current configuration and parameters are shown in the LCD. The parameters are comprised of alarm mode, low temperature limit, and high temperature limit. Using two push buttons labeled UP (+) and DOWN (-), the user can set the high and low temperature limits. When a limit is exceeded, a red alarm LED shall light regardless of beeper status.
The three pushbuttons were scanned using 3 of the 4 data lines already used for the LCDto conserve I/O lines on MCU.
This temperature alarm uses a 2-line LCD display where the current temperature is shown in both Celcius and Fahrenheit degrees. The user is allowed to set independent high and low temperature alarm points by featuring a 3-key keypad. The minimum and maximum temperatures encountered is also recorded by the alarm. The design of the unit makes it configurable by the use to function either as a temperature alarm or a thermostat with the difference of producing intermittent beep when a limit is exceeded if used as alarm.
The current configuration and parameters are shown in the LCD. The parameters are comprised of alarm mode, low temperature limit, and high temperature limit. Using two push buttons labeled UP (+) and DOWN (-), the user can set the high and low temperature limits. When a limit is exceeded, a red alarm LED shall light regardless of beeper status.
The three pushbuttons were scanned using 3 of the 4 data lines already used for the LCDto conserve I/O lines on MCU.
CIRCUIT DIAGRAM
CODE
To download the related codes for this project click on the below link