[vz-dev] volkszaehler-dev Digest, Vol 22, Issue 12

[Willy Verbiest]

> Hello Willy,
>
> Gas Resolution: I guess 100000 is right.
> ( I could only guess, i also wondered in the beginning about strange
behaviour / very high consumption, but played around with different values,
and this > seems to be the right one)
> But I still have problems to find the right reed contact for my gas
meter, i already ordered 5 of them, none worked, all not sensitive enough)
>
> I would appreciate if you could make some documentation about the maxim
library, at the moment i use a Net-IO, but as i also want to read out /
show my gas heater ( viessman), maybe i?ll switch to a small linux system (
i guess Net-IO is to weak for that)
>
> Best regards
>
> Klaus

Hello Klaus,

Thanks for the numbers, I had the same value when I did the tests.
Some more details about my configuration:
I use the ALIX.1D embedded board with Debian 6 installed on a 4GB
CompactFlash.
Debian 6 was installed on the CompactFlash when the CF was in a cardreader
and I had booted my PC from the Debian install CD.
I didn't install the gui.
I've installed the gcc compiler.
I use a 1-wire adapter (I can compile my source for both the USB or the
Serial port adapter)
I've made a directory for my source code and a subdirectory for the 1-wire
library.
I've made a makefile with the compiler directives to compile for the 1-wire
USB and 1-wire Serial port adapter.
My program code uses a configuration file and a sensors file.
The volkszaehler is updated by means of the middleware i.e.
For the Electrical meter & Gas meter:
wget -O- "
http://192.168.1.49/volkszaehler.org/htdocs/middleware/data/72574ec0-f405-11e0-b430-b73bcecafc42.json?operation=add&value=1"
>/dev/null 2>&1
For the temperatures:
wget -O- "
http://192.168.1.49/volkszaehler.org/htdocs/middleware/data/40b64180-3589-11e1-8d2d-fddd6b40d581.json?operation=add&value=53.2"
>/dev/null 2>&1

For the Electrical meter I use the BN-3084-WS "3phasiger Drehstromzähler
mit statischer LCD-Anzeige" which gives a pulls every 1,2 Watt (open
collector).
I have no slippage between this counter and the real one.

For the Gasmeter I use the CNY70 sensor and a self made board with a CA3140
IC and some resistors.
Both meters are connected to a 1-wire counter board from Hobby-Boards.
The temperature sensors are of type 1-wire DS1820.

The gas counter give's me some errors, the sensor is placed in front of the
3th digit after the comma this digit has a mirror for number 0. When I did
the tests in my "labo" I've measure 0,002 Volt on the CNY70 emitter without
a mirror and 1,000 Volt with a mirror on about 5mm distance from the CNY70
sensor.
When installed the CNY70 sensor on the gas counter I've measured 0,20 Volt
and 0,25 Volt when the mirror was in front of the sensor.
This is very little variation and I have to set the voltage on pin 3 of the
CA3140 on 0,25 Volt.
Testing over a period shows that there are read errors.
Here some result:
Time begin;Time end;Counter begin;Counter end;Diff. m3;Calculated
Ticks;Database Ticks
12/01/12 23:40;15/01/13 14:25;25.503,731;25.519,325;15,594;1.559;1.764
That's a difference of +205 ticks over a period of 62h

The mechanical problems are:
1. There is already a reflection from the surface from the gas counter even
when the mirror is not visible and there is no direct light towards the gas
counter.
2. When the mirror is visible the sensor does not pickup enough light.
3. Position the sensor is very difficult to do.

I will further monitoring the gas counter.

Kind regards,

Willy Verbiest
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