May 13, 2014

The Wireless Pulse Counter will take over from the old Wireless Energy Meter

EDIT (2014-09-21): I have added RFXMeter compatibility so that the WPC will show up as a RFXMeter and thus be natively supported in Domoticz. Available in WPC sold from this date. Here is an instruction for how you configure it in Domoticz.

EDIT (2014-09-15): Added information about support for the LED-pulse detector from

The old Wireless Energy meter serves its purpose, but it has a few shortcomings.

Here is a new product that I call Wireless Pulse Counter (WPC). This is a better name compared to the old Wireless Energy Meter, since it is actually only counting pulses, not energy or liters.

Since it is only counting pulses it is also much more versatile.

  • You can combine the WPC with a reflex detector (TCRT5000) and measure water flow, gas consumption or electric energy consumption if it is of the rotating disk type.
  • You can count the amount of blinks from an Electric energy meter. Both LED and S0 output is supported.
This is how you connect the WPC to a S0 interface. The current through the S0 port need to be limited.
A resistor value of R=330Ω is OK.
The LED-pulse detector from is very very sensitive. The sensitivity can be reduced by adding a resistor R between S0- and GND on the WPC. A value between 820Ω and 4k7Ω seem to be reasonable values. Lower value => lower sensitivity.

From the counted pulses you can then calculate the consumed water/energy/gas/events etc.

The new WPC will fit perfectly in a plastic box from Hammond, with the dimensions 20x35x50mm. Note! I have not decided on a box with or without flanges as in the pdf.

The power feed is changed to a micro-USB instead of a mini-USB connector. In this way you will very likely already have a power source for it. You can just reuse an old Android-mobile charger to power it.

Most people do not have a soldering station at home. This version comes with screw terminals so that a  soldering station will never be needed.

It is professionally assembled with perfectly soldered components.

Further more, I have changed the protocol to a simpler variant. All credits to Stefan Strömberg at OpenNetHome for this suggestion.
With this new protocol you can drop several packages. Lots of packages. Still, even with only a few packages received, you can trust that they reflect the consumed energy. The solution is utilise the Humidity data field as counter data in the same way as with the temperature data field. In this way it is possible to have an always increasing counter.
It will wrap around, but the maximum counter value will be so big so that there will need to pass several hours of lost packages to mess up the energy logging.

Note that in the normal case you do not loose many packages, so the above text describes the extreme situation.

As soon as I have finished the verification of the hardware, I will make it available in the foogadgets store.

EDIT: It is now available in the web-store

No comments:

Post a Comment