The hardware is the kit from this page:

http://www.qkits.com/serv/qkits/diy/pages/QK145.asp

It is very quick and easy to build and plugs straight into the serial port. I had mine built and taking readings in about an hour and I'm hopeless with a soldering iron.

Reading values from it is very easy, just read from the serial port and you get:

R V1.0 2001-10-13 11:56:11 C



1 0026.75

The first line is just a version number of the eeprom code. You then get one line for each sensor (I only have one plugged in at the moment).

I have the following (very) simple shell script to read a single reading:

#!/bin/bash



echo `head -n 3 /dev/ttyS0 | tail -n 1`

I use MRTG to plot the graph. Unfortunately MRTG only knows about whole numbers so I have to times the temperature reading by 100 and plot that. The script that I point MRTG at looks like this:

echo "`/usr/local/bin/tempread |cut -c 5-9` * 100" | bc | sed s/.00$//

echo "0"

echo "0"

echo "0"

Probably horrible, but I'm no shell script expert...

Finally, the chunk from my MRTG config file looks like this:

Target[temp]: `/usr/local/bin/tempmrtg`

MaxBytes[temp]: 4000

Factor[temp]: 0.01

Options[temp]: gauge, nopercent, noo, transparent

XSize[temp]: 600

YSize[temp]: 150

YLegend[temp]: Temp

ShortLegend[temp]: C

LegendO[temp]:  Nowt:

LegendI[temp]:  Temp C:

Title[temp]: Server room temp

PageTop[temp]: <H1>Server room Temperature

 </H1>

  <TABLE>

    <TR><TD>System:</TD><TD>Server room temp</TD></TR>

  </TABLE>

I must get round to connecting the other sensors, one for outside temperature and the other two for inside my two servers.

P.S. I should be using RRDTool instead of MRTG as it knows about fractional numbers and does better graphs. Whenever I look at it I can't work it out though. I think I'm getting old and stuck in my ways...