Temperature Recorder Built Around PIC12F683 Microcontroller

Overview

A Microchip PIC12F683 microcontroller is utilized in this project along with a serial EEPROM and a thermistor in order to produce a temperature recorder device.

Details

Up to 32000 measurements can be stored by the 32kBytes EEPROM as the temperature is measured and stored at user programmable intervals that can be from 1-256 seconds. A range between -40°C and +100°C can be provided by the combination of thermistor and analog circuit. The start time can be set into the EEPROM and programming the device can set the time interval. The components are obtaining a very low current consumption of approximately 50uA or about 1mAh per day since the PIC will be asleep and the EEPROM IC is inactive most of the time.

A battery pack with 4xAAA batteries is used to power the temperature recorder as the overall size of the unit is measured 40mm x 26mm x 16mm. The external thermistor will be plugged in as the connector on the end contains power, I2C clock, and data & analog input. The same I2C bus will be shared by the EEPROM, PIC, and external connector and the PIC uses the thermistor when needed.