Realization of an Inexpensive Embedded Mini-Datalogger for Measuring and Controlling Photovoltaic System

Abstract

This article describes the design and the realization of an automatic recording device for measurements and controls of multiple physical parameters, in order to manage and monitor a mini central photovoltaic (PV) electricity. It is based on an 8-bit microcontroller, a PIC16F716, which is the lowest cost in the midrange portfolio from Microchip. The automatic recording device (or datalogger) measures the following parameters: the current sourced by a set of PV panels to solar batteries, the voltage across these batteries, the internal and the external temperatures, through a 4 channel multiplexed 8-bit analog–digital converter (ADC) integrated module. This datalogger is clocked with a real time clock and calendar (RTCC), which controls also the periodic measurements. These are stored in an external 8 kB flash electrically erasable/programable read-only memory (EEPROM), a 24LC64, using the I2C protocol, which allows us to easily increase the storage capacity by adding, if necessary, in parallel, up to eight external flash EEPROM.