For those who have read my last teardown of the Efergy HM01 Energy Monitor, they would have noted my discovery that it was not compatible with EfergyRPI_001 decoding through rtl-sdr due to a different FSK data format. I haven’t had any time or inclination to better understand the HM01 format, although it superficially does look simpler.
Instead, I had another different unit on the way. I was using an Efergy Elite 1.0 at home at the time, and as that unit is discontinued, my only option was to order its successor, the Elite Classic 2.0. This unit itself may have already been superseded at the time that I publish this post, as mentions of the Elite Classic 3.0 have already started popping up on the internet.
The unit arrived not long after my HM01, although, as I was tied up with other work, I forgot all about it until I “rediscovered” it under a pile of stuff. So here’s quick review and teardown.
The Efergy Elite Classic 2.0 comes in a cardboard box which illustrates the receiver LCD and its options. Quite simple and yet, also a good preview of what the unit is capable of. The unit itself is about $80 posted to Australia from the UK (via eBay).
The rear of the box gives you an illustration of how to install and run the unit – it’s almost enough to use it without the need for reading the manual. A short manual is included, along with the listed items. You will need six AA batteries, three in the transmitter, and three in receiver.
The rear illustration already shows some differences to the Elite 1.0, such as the increased decimal digit accuracy, and the inclusion of temperature and humidity sensors. I should make a note now, the receivers and transmitters for the Elite 1.0 and 2.0 aren’t interchangeable in the sense the Elite 1.0 R (LCD) doesn’t detect the Elite 2.0 transmitter and vice versa.
Despite this, EfergyRPI_001 manages to decode the transmissions from the Elite 1.0, Elite Classic 2.0 and E2 successfully. Those are the only ones I know to work with similar transmission formats.
So that’s a BIG bonus!
You will note that the revision of the product isn’t noted on the front or back of the box, and can only be seen from the underside. This one also seems to list its firmware revision as being 2.0.
Here are the items included in the kit. There is a short manual, the LCD receiver itself with a protective film, the transmitter (with two ports covered by removable rubber caps, to be used with additional current transformers if on a three phase installation), and the current transformer which attaches with a 2.5mm TRS jack.
I did give it a short spin – and all I can say is that it has the same allure as the original Elite 1.0, and works pretty much equally well. The additional digit on the LCD is nice, as is the temperature and humidity display, but it doesn’t warrant an upgrade if you’ve already got a 1.0. The transmissions were equally reliable and the range didn’t seem to differ. The bolder font on the buttons and the new logo colouration is probably good as well.
The build quality is miles ahead of the HM01 – and the price difference is small. I would advise anyone looking to buy the HM01 to buy this instead.
Tearing it Apart
Here comes the fun bit – looking at each of the bits and pulling it apart. One thing that has changed is the printing on the products, which allude to large numbers of certifications – this wasn’t present on the Elite 1.0, and gives us a chance to chase down who is responsible for the unit altogether. Feel free to compare how the insides of this energy monitor compares to the HM01.
The receiver unit claims to be designed in the UK and Made in China, just like the Elite 1.0. The receiver unit is so well built, and no screws are obviously evident that I took a while to work it out – the grey soft-touch sides come off to reveal the screws. One thing that’s different is that the input is now specified as DC 5v, whereas the Elite 1.0 specified DC 6v. It’s not much, and since the unit happily runs off Sanyo eneloop cells for about 1.5 years on a charge, I wouldn’t consider using a wall wart for it anyway.
For fear of breaking it further, I didn’t pull it apart further than this.The PCB is marked with WPM101V01-01V13, with a label stating WPM101-6SRX-V30. I believe WPM is supposed to stand for “Wireless Power Meter”, and WPM101 is the “product name”.
You can see there’s actually quite a few things inside the unit:
- Coiled antenna on the left.
- Three crystals – one near U1 which would be for the radio link, one near the main MCU and another underneath it (likely for MCU RTC).
- Four surface mount LEDs towards the bottom of the PCB for the alert light.
- Temperature sensor on the top left, with humidity sensor in blue below, and alert buzzer.
- Plug-removable battery input, and wall-wart input.
- Holtek HT46RU66 8-bit RISC A/D and LCD MCU, with FT24C02A 2kbit EEPROM next to it.
- Amiccom A72C01AUF ASK/FSK receiver.
As it works with EfergyRPI_001, we know it’s a 433Mhz FSK unit.
The transmitting unit looks just like the one for the Elite 1.0, just that it’s got different printing on it. Even the transmit interval selections are the same. The rear actually provides lots of important regulatory information that can be used to track them down -
- The FCC ID of XRQELITE20 corresponds to this application. As it turns out, this one was filed by someone at Timco Engineering, contact specified as the Director of Efergy, with testing done by Waltek Services (Shenzhen) Co., Ltd.
- Interestingly, the above FCC application specifies the frequency as 433.485Mhz, with no difference in the lower and upper frequency. A zero bandwidth device? I think not!
- Anyhow, the application was a change of identification from the original FCC ID of NDZWPM101 granted 26th August 2009.
- Tracing the report for NDZWPM101 reveals the applicant as Precision Enerprise Ltd, likely the real manufacturer of the product. It makes sense as they already have energy monitoring products, although this one is likely contract manufactured specially for Efergy.
- This application is for “original equipment”, so the buck stops there, but the product code being WPM101 matches that FCC ID application giving us confidence we now know what’s “going on”.
A peek inside the transmitter shows the same sort of coiled antenna used. Some electrolytic caps are mounted on the side to reduce vertical profile. There is a bi-colour LED used to indicate the transmission time. The PCB is marked with WPM101V02-02V11 and dated with 22nd February 2011. The label states WPM101-TX-6S-V21.
The other side of the PCB shows the push button, another three crystals (one RTC, one MCU and one radio) and a bunch of “regular” components. There is an Intersil 12058IBZ RTC timer visible (which uses the circular crystal). There is an Amiccom A7302C FSK transmitter IC as well.
The labelled component is …
… surprise surprise! Another Holtek MCU. I suspect someone there really likes their Holtek RISC MCUs. This one is the Holtek HT46RU232 One Time Programmable A/D Type 8-bit RISC MCU.
There’s not much to it, it’s mostly magnetics as you can tell from this image:
There are a few passive components on the other side of the PCB, maybe to clamp the range of voltages to something “safe”.
If you’re an rtl-sdr fan and you’re looking for a wireless power monitor to start logging data from – this one definitely works with EfergyRPI_001. This unit is of a quality build, sharing much heritage with the original Elite 1.0 which I have found to be reliable and dependable. Price wise, it’s not significantly more expensive than the HM01, which isn’t yet decodable, and it has superior build quality.
The quick look through the internals should give you an idea of how it’s been made – with many microcontrollers glued together rather than ASICs. This seems to be a common trend with products nowadays, but they have not neglected to put in a few more frills over the original Elite 1.0. Temperature, humidity and one extra digit of precision are definitely welcome additions.
By doing this, I’ve also managed to gain experience in using FCC IDs to track down OEMs – a common practice to try and nail down the OEM in the case of computer power supplies for example.
Best of all, nothing was hurt in the process of making this teardown :).