Hi all,
You might be interested in a Christmas project I’ve been working on to monitor gas consumption over time.
I found some information here. This is based on the idea that some gas meters have a reflective spot on the 6 digit of the lowest reel. We can point an LED and sensor at that reel to detect each revolution. They recommend a CNY70 as the sensor.
I wanted some low cost, meshable, RF units that I could use for the sensor devices and these XRF units from Ciseco are very good, at about £10 each. (The support from the Cisceco guys is pretty fantastic too). The XRF is based on an 8051 core with digital I/O, some ADCs and a radio. With some custom firmware in one of the CC1110 ICs in the XRF and a standard firmware build in another XRF connected to the Vera via USB-Serial I can send pulse counts into Vera.
I have some Lua code monitoring and parsing incoming pulse counts. I want to get this hooked into the energy monitoring software components at some point in the future.
In the meantime the Lua code is publishing results up to a Pachube feed here using Shadock’s example
If anybody is interested in looking at this I’ll be happy to answer any questions or assist 
Cheers,
Alex
Dynamic Devices Ltd
Very intereted Alex,
Do you have more information on the hardware & software use?
Does it measurement kubic meters or something else?
Thanks,
Jack
Hi Jack,
Do you have more information on the hardware & software use?
The XRF is based around a Texas Instruments CC1110 which is an 8051 CPU core with a radio integrated. Datasheets and manual are here
The Ciseco people have their own closed source firmware which provides a passthrough functionality - at its most basic like a serial cable replacement - and some level of digital control capability. From my conversations with them they are working on extending their firmware to handle additional sensors.
Given the IC is a CC1110 it is possible to replace the standard firmware with a custom build. I’ve used a free version of the IAR compiler (kickstart) which targets the CC1110 with some software examples from the TI page I link to above to put together a simple pulse counter and radio transmitter firmware build.
Does it measurement kubic meters or something else?
My meter is measuring m3. Each time the lowest reel of the meter rotates this is 0.01m3 used. The firmware gets a pulse each time this happens and thus we’re just counting up pulses, each of which correspond to 0.01m3 of gas used.
There is a straightforward multiplication that can be done to convert m3 to kWh used. For the EON energy supplier this is
M3TokWh(x) = (x * 1.02264 * 39.2) /3.6
Then of course, knowing an estimate of the cost per kWh of gas (about 3.7p for me) we can determine costs.
Cheers,
Alex
Dynamic Devices Ltd
The Vera device I’ve put together implements the energy meter service, and thus exposes a “KWH” variable.
I’m setting this periodically (currently every 15 minutes) to the kWh used in that time, based on the pulses received converted from m3 to kWh as above.
I use Chris’ “dataLogger” plugin which handles monitoring of variables and thus we can easily graph the Gas usage in kWh.
(I might need to double check if the energy meter KWH property should be set in a different way)
Cheers,
Alex
Dynamic Devices Ltd
Hi, you probasbly know of the NothQ NQ-9021 meter… I can’t find any reliable information on this device being able to read my gas-meter. I am very intereseted in your solution. Would this “device” be just a normal Zwave device in Vera? Any “guideline” or “make-this-device-for-dummies” manual available?