IotaWatt 4.0

Tags: #<Tag:0x00007f1be60fef98>

(blazejka) #133

Anyone have a spare PCB (or 2) for sale?

(Sergii Kabashniuk) #134

I have a couple of questions related to PCB license and schematic. Can someone take a look?

(Philip Barclay) #135

Awesome work getting through the EMC tests. I know the pain (and cost) when things go wrong in these sorts of tests. Now that it has passed this milestone is is likely to be stocked in the shop any time soon? And any idea on pricing yet?

(Inactive) #136

Looking at some log issues and may be able to deliver PF and Frequency with the changes, depending on the time window and interval needed. What are your requirements?

(Glyn Hudson) #137

Hi guys,

Good news! The IotaWatt is now live in the OpenEnergyMonitor web shop :tada::smiley:

We have a few units ready for immediate shipping with a further batch of 80 units arriving next week with a larger run to follow. We also have some larger CT’s (200A max : SCT-019-000) and smaller CT’s (20A max : SCT006-000) to complement our default CT’s (100A max : SCT-013-000). These new CT’s will be added into the shop tomorrow.

As a thanks for helping and being involved in the development process I would like to offer a 20% discount off IotaWatt for forum members, just use code B3806G5BM3 at checkout and enter your forum username into the order comments field*.

*Code is valid until 20th October 2017, one use per user.

The forum post is a ‘soft’ community launch. An official launch will take place in a few weeks once we have everything ironed out. I just wanted to give you guys a heads up. Please let me know if you spot any errors on the shop listing or the IotaWatt user guide (work in progress) and obviously please report any IotaWatt bugs to the forum.

Thanks again for your support.

The IotaWatt is a very exciting addition to the OpenEnegyMonitor ecosystem. Big thanks to the hard work by @overeasy for making the IotaWatt a reality. We have been in active communication with @overeasy for most of 2017. IotaWatt is a collaboration between us (OpenEnergyMonitor) and @overeasy. The vast majority of the design and development has been done by @overeasy. We have assisted with certification and compliance testing, component sourcing, manufacturing, shipping and general beta testing.

Here are a few photos of the production IotaWatt.

We’re currently investigating screen printing options for the enclosure for the next batch.

IotaWatt in Manufacturing
(George (aka Costas the coder)) #138

Congratulations to all involved, it looks a nice piece of kit for users that require multi channel monitoring.

(Philip Barclay) #139

Awesome work to everyone involved, it certainly looks like a fantastic product. I look forward to seeing the lower current CTs in the store, these seem like a great solution for monitoring single power circuits. Time for a count-up of the circuits in my distribution board.

(Dave) #140

Ordered mine, cant wait to have a play :slight_smile:

Credit to @overeasy and the team!


(Dominik Westner) #141

That indeed looks very nice. Unfortunately I’m very space limited and the plugs and attached cables seem to take a lot of space.
Is there any reason why not to use the reference AC-AC converter also as power supply? (Needs to be rectified to DC internally obviously).
This also would reduce installation size and complexity.

(Glyn Hudson) #142

This is exactly what we do on the emonTx, however the increased power requirements of continuously sampling and wifi connectivity mean that its not possible to to power using AC-AC without distorting the AC waveform.

(Inactive) #143

It’s just not possible to full-wave rectify the AC reference and then use that DC to bias the same AC. The emonTX uses a half-wave rectifier and has very low power requirements - I think you can actually run it for quite awhile on batteries. IotaWatt uses < 1 watt but still, that’s a lot to draw off a half wave rig without asymmetrically distorting the reference.

Another consideration is that 5V usb power supplies have become the de-facto power standard for small devices, and there is a competitive market with good, inexpensive devices available throughout the world. Contrast that with the diminishing availability of 9V AC wall transformers and the problem becomes one of designing to use a component that may not be available in a few years. IotaWatt will accept a 12V AC reference, so a little grace there.

(George (aka Costas the coder)) #144

@overeasy if IotaWatt was sampling say 2 channels rather than 14 channels would it be possible to use the AC - AC (with hardware / firmware mods)?

(Minos Eigenheer) #145

I would like to use the IotaWatt in a 3 phase setup. Could anyone explain the hardware/software modification to connect the 9V AC-AC voltage sensor adapter to a 1 VAC current sensor input.
Can IotaWatt automatically detect the matching voltage reference for each CT no matter where I plug in the CT?
What happens if a CT gets moved to an other phase? Does IotaWatt change the voltage reference automatically?
We use 3 independent single phase DC-AC inverters. They are not connected to each other on the AC side. What happens if the phases are not 120° from each other and maybe not even have the exactly same frequentie?

(Inactive) #146

With all due respect to everyone who wants to make suggestions to remake this device before trying it out, I’ve spent a year wrestling with scores of design issues and this is the result. There is a thread for “Homebrew IotaWatt” where there are already several folks that are doing the hobbyist enthusiast thing. I am supporting those efforts to the extent that the proponents are actually building the changes they would like. In the end, I suspect there will be some feedback of those efforts to this production unit.

For now, understand that I designed and built this device specifically to be useful to those who do not want to build and modify their own devices. I wanted to eliminate the need for a perpetual thread in these forums telling folks how to calibrate and reprogram their device. I wanted to offer the average person the ability to monitor their home use, PV or other alternative, solar diverter, EV change appliance, whatever, with simple plug in CTs and browser based menu picks. If there is anyplace I would like to concentrate my efforts going forward, it’s in improving accessibility to non-technical users.

So this is a fork in the road. Folks who want to start their own redevelopment thread can move to homebrew and I’ll be there to share my past experiences to inform those efforts. Those who want to just use IotaWatt as a data collection device and talk about how to do that and what to do with the data, I’ll be here to help with that.

There’s something for everyone - all it’s proper place.

(George (aka Costas the coder)) #147

I’ll post the same question in homebrew then.

(Inactive) #148

IotaWatt was designed with the intention of having 3-phase capability. At this point it’s all academic. I don’t have ready access to a three phase installation to further develop and test the capabilities. There are a couple of folks on the homebrew thread that are playing with that in European 3-phase residential settings. With this rollout, I’d like to start working with field people to explore these capabilities. I have some parts coming in soon to make simple adapters to allow using any channel as a voltage reference channel.

I’d like to start a three-phase iotawatt thread to focus those efforts and provide more specific support to the various approaches possible with IotaWatt. I’ll set that up within the next day, and ask that you go there and we can start to define and elaborate on these three-phase concepts and solutions.

(B Rotten) #149

Ordered one, thanks.

(Glyn Hudson) #150

It will be difficult since the ESP8266 uses considerably more power than an ATmega328 (used on emonTx) when WiFi is connected. If you really want a single AC adaptor solution you would be better off using an emonTx. See our blog post on the design of the AC-DC half-wave circuit used on the emonTx.

(George (aka Costas the coder)) #151

@glyn.hudson I ordered the emonTx last week, thanks.

Homebrew IoTaWatt
(Glyn Hudson) #152

New CT’s are now in the shop :+1: