Battery Monitor & Temperature Logging Device

Purpose

Monitoring the connection of 8 batteries to a small solar plant and logging of 3 measured temperatures each hour. Further use of the logged temperature data on a PC running Linux. The device is extensible and improvements such as directly displaying the actual temperature are planned.

Features

8 analog inputs, mean & deviation calculation, optical warning when limits get crossed.
3 analog inputs for temperature measuring with epcos S891 10k ntc resistor
logging of the 3 temperature channels into eeprom every hour during 450 days
communication with PC using RS232

Hardware & Software

The heart of it is a PIC16F73 which controls an 8x analog MUX (HI3-508A) and a 32k x 8 SPI EEPROM (M95256). For communicating with a PC it's using a RS232 at 9600 baud (line driver: DS14C232).

The GUI isn't finished and probably won't ever be. I just implemented what I need and left the rest. Feel free to finish it, I'll appreciate any patch (please use 'diff -u').

Everything you need to build it: eagle files (finished pcb layout, schematic: also as png and ps included), firmware, GUI & debug-tools
battwdg-20040821.tar.bz2 [766 KB, 2006-03-11]
Firmware of the PIC:
firmware-01.asm [36 KB, 2006-03-11]
Schematic (get the "everything you need file" above for better quality)
GUI screenshots (uses gtk+2.x and OpenGL):
- current values
- logged temperature data
- calibration
Logged data: 2005.log [32 KB, 2006-04-13]
start: 2005-01-01 11:04
end: 2006-01-01 11:53