Utility Meter LED Pulse Sensor -- use in Canadian setting

Hi everyone,

I’m new to this forum, but have used some of the emoncms software in the past.

I am interested in implementing whole-house electricity usage monitoring in my home. I live in Canada (our electrical system is similar or identical to the US system) and happen to already have an MQTT / Node-Red plus database setup for recording and graphing temperature and humidity information inside my home (using ESP8266 devices).

The Optical Pulse Sensor sold on this site Home | OpenEnergyMonitor seems like an attractive option for fairly “simple” whole-house electricity monitoring. I understand that it reads the IR pulses counting off watt-hours consumed, and “translates” them into longer digital pulses that can then be read via an Arduino. (I could calculate power consumption by measuring the time elapsed between pulses, or something like that).

I would be interested to know how easy these are to use in practice. My electricity meter is mounted on the outside wall of my house, exposed to the elements all year, and I’m not sure how robust the Open Energy Monitor pulse sensor is.

I can buy an “integrated” and weather-proof pulse counter from Amazon, but this is a “closed” system that is designed only to transmit power usage information to a proprietary display. I need something “open” so that I can harvest the data, which is why I’m here.

Any tips would be much appreciated!

Hi, welcome to the forum :slight_smile:

Incorrect, the optical pulse sensor reads the visible flashing LED (usually red), see example.

The sensor is a sealed unit and should be relatively robust, however we have not tested waterproofness! In a non-scientific test when we opened up one of the sensor the inspection I can confirm they are very sealed!

The sensor outputs a TTL pulse corresponding with the LED flash.

The sensor I purchased via the OEM Store can see IR pulses. And that is what it states on the Store website.


My outdoor utility meter only outputs IR pulses. You’ll need to install an IR Pass Filter to block ambient light. If you’re interested I can tell you what I did, but you’d never believe it!. My pulse sensor has been mounted outside for almost 12 months.

Good point, sorry I forgot that it can also detect IR light, it’s designed primarily to monitor visible light which is what most utility meters pulse output.

Good to hear the sensor has been tested to be relatively weatherproof!

With regard to IR sensing it’s also possible to read some Elster meters direct serial output : Reading Watt-hour data from an Elster A100C electricity meter using IrDA by Dave Berkeley part 2 - Blog | OpenEnergyMonitor. I wonder if our standard pulse sensor can be used for this…

Thanks very much – I would be interested in knowing what you did.

My particular meter is the Elster R1S. It seems to be locked down pretty tight by our local utility. There is an IR LED on the meter face that apparently pulses once per watt-hour.

I had thought that measuring its IR pulses to gauge energy consumption would be easier than using current transducer clamps inside my home’s electrical panel, but with the complexity of weatherproofing a pulse-counter, running wiring through the exterior wall of the house or a radio setup, etc., I’m beginning to rethink my approach!

@JordanW - I used s paper punch and a 3.5 inch HD floppy disk. :grin:


Take the small floppy punch piece and slide it between the velcro and the sensor case.

Now the sensor won’t react to bright light.

I can’t take credit for the idea. I found the idea here:
Poor Man’s Cell Phone IR Filter


I would be interested in the success of this endeavour, @JordanW. Did it work?
I would try it, if I had any floppy disks around…

Nice! Very clever :wink:

Unfortunately I haven’t had a chance to give it a proper try yet. I have the phototransistor in hand but have yet to connect it to the Arduino or test it out thoroughly.