My house has an analogue water meter reader with dials, so the only way to read it is using an image and getting the reading from it.
A cheap usb webcam with LED lights was used. Application used to take images is fswebcam (apt-get install fswebcam)
Dialeye is configured to read the image using Python. DialEye has great instructions for setting it up: http://olammi.iki.fi/sw/dialEye/After calibration the image looked like this
The test run looked like this
 Running the Dialeye python command turns out as a number like this $ python dialEye.py -r meter docs/dialeye_calibration.jpg
Writing dialeye_result.png
0692
Every five minutes a cronjob is run that takes a photo, reads the image with DialEye and stores the results in a file. It is then uploaded to Openhab with curl using the REST API. The old result is stored each time so a cumulative and a 5 minute average is read. $ more dialeye.sh
#!/bin/bash
#Cleanhouse and log results
cat /home/pi/scripts/dialeye/dialeye_result.txt >> /home/pi/scripts/dialeye/dialeye_result.log
mv /home/pi/scripts/dialeye/dialeye_result.txt /home/pi/scripts/dialeye/dialeye_result_previous.txt
#Take snapshot and read with Dialeye
fswebcam -r 640x480 --jpeg 95 /home/pi/images/dialeye.jpg
python /home/pi/scripts/dialeye/dialEye/dialEye.py -f /home/pi/scripts/dialeye/dialEye/dialEye.conf meter /home/pi/images/dialeye.jpg > /home/pi/scripts/dialeye/dialeye_result.txt
#post to Openhab via curl, read variable from text file
read -r -d '' str < <(cat /home/pi/scripts/dialeye/dialeye_result.txt)
curl --header "Content-Type: text/plain" --request POST --data $str http://192.168.1.45:8080/rest/items/Vedenkulutus
#Count average water 5 minute consumption and send to Openhab
read -r -d '' strold < <(cat /home/pi/scripts/dialeye/dialeye_result_previous.txt)
COUNT=`expr $str - $strold`
curl --header "Content-Type: text/plain" --request POST --data $COUNT http://192.168.1.45:8080/rest/items/Vedenkulutus_now
This results in Openhab with a total litres (according to the meter) and a 5 minute average. Finally I configured the Cacti to read the Openhab REST API and draw Graphs from the data.
Below are live graphs of water consumption and the webcam image of the water meter.
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