[vz-dev] Volkszaehler with 1-wire counter (progress report)

[Willy Verbiest]

Hi Steffen,

The volkszaehler demo database is now running on my embedded PC (ALIX.1D).

I will follow your recommendations and fill the database by sending a HTTP
request
http://localhost/volkzsaehler.org/middleware.php/data/
<uuid>.json?operation=add&ts=<timestamp>&value=<relative>

I'm thinking to do the following:
Define a cron job to run a PHP script every minute
The PHP script will read the sensor table (1-wire temperature, 1-wire
counter).
Going in a loop through all the sensors.
For each sensor:
Start a c program with parameters and get the results of one reading by the
standard out or some other OS mechanism.
Store the current time, the current value and the previous value in the
sensor table.

If it is set in the table then the sensor value will also be send to the
volkszaehler database with a HTTP request.

The 1-Wire counter is a read only 32 bit counter to get the number of pulses
I have to take the previous counter value and the current and make the
difference.

At this time:
I have installed an electrical meter and have made a connection to the
1-Wire counter module.
On the pc board there is a little c program running to get the values from
the 1-wire module.
I have checked the counter of my new electrical meter and the current value
of the 1-wire counter module and I will recheck it at the end of the week to
see if there is any drift between the both.

I use the meter from MBW Electronic
http://www.mbw-electronic-online.de/3phasiger-Drehstromzaehler-mit-statischer-LCD-Anzeige


You wrote:
“Hint: you need to create your meter with &resolution=1000 (which stand for
1000 impulses/kWh = 1 Impulse/Wh)”

The meter from MBW Electronic gives 800 pulses for 1 kWh
Is this a problem?
Do I have to do some recalculations?

Kind regards,

Willy Verbiest
Wondelgem (Gent)
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