Microcontroller temperature logging system

A system for logging temperature data and PC data storage and graphing

This microcontroller-based temperature logging system logs powers up microcontroller peripherals and logs temperature readings from temperature sensors enclosed in stainless steel pipe buried in composting organic material to EEPROM at specified intervals for remote retrieval via PDA and final storage in a PC database. The 2-layer PCB measuring less than 2.5" (63.5mm) square is enclosed in a small, durable, weather-resistant cast aluminum enclosure located at a convenient place on the pile for easy data retrieval. The device consumes well under 200uA in typical operation, can handle up to 5 sensor inputs, and monitors its own battery voltage, alerting the user of the need for a battery change upon device synchronization. Firmware for the microcontroller was developed in PICASM, and software for the PDA and PC was developed using Microsoft Visual C++ (standard and embedded versions). The PCB was designed with flexibility in mind to allow it to be used as a general-purpose application board for the PIC16F877(A) microcontroller.

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