Computing stuff tied to the physical world


AC current node prototype

In AVR, Hardware on Oct 27, 2011 at 00:01

Time for some pictures. Here’s the “AC current node” prototype I’ve been working on:

DSC 2680

And in case you’re wondering: that’s a simple plastic enclosure I found a while back, which looks pretty much like (and probably was intended as) … a game catridge!

Here’s the completed unit with a test hookup:

DSC 2690

You can see the transformer-less power supply, and an ATtiny84-with-RFM12B board, which I’m tentatively calling the “JeeNode Micro” (“JNµ”) – 16 x 48 x 4 mm:

Screen Shot 2011 10 17 at 21 18 07

Please note that I’m using this for internal projects for now. I haven’t figured out whether it’s suitable for the shop, since the JNµ is different from a JeeNode in several ways, not in the least in that it requires quite a bit more hand-holding to develop “sketches” for and to load them into the unit. This isn’t even the first JNµ board – I’ve tried several different layouts in the past.

For this particular project though, it’s quite a good fit, both in size and due to the ATtiny’s differential ADC plus 20 x gain stage. I’ve yet to hook up the analog input to the sense resistor, BTW. It’s all work-in-progress…

  1. That’s quite a handy sized box. Do you have a name/model for it so I can taunt myself by finding it’s not available in the UK?

    Oh, and the JNµ is nice too ;-)

    TankSlappa 27 October 2011 at 12am

  2. Gosh I would like about 20 of these :-) All I need to add is a PIR, stick them in some solar garden lights as the power source and I am away.

    Tim Hoffman 27 October 2011 at 2am

  3. I love jeenode micro!!! I hope it works out. I think that would be a great addition to the jeenode family

    Dolabra 27 October 2011 at 3am

  4. Love the micro. A little hand holding doesn’t matter.

    I want it … and I want it now ;)

    anti 27 October 2011 at 9am

  5. Watching with considerable interest as something very similar could be really handy in a battery management system I have in mind.

    Ed Davies 27 October 2011 at 11am

  6. I’d love to see this in the shop.

    JohnO 27 October 2011 at 11am

  7. Add a solid state relay and you will manage plugwise like network (http://www.plugwise.com)

    Pap 27 October 2011 at 12pm

  8. I’d be really glad as well to see the JeeNode micro in the shop ! Smaller and maybe still cheaper than a JeeNode, and with that 20x amplifier, it sounds great… the lack of “easyness” should not be such a disadvantage !

    Regards and thanks for all.

    Hamlet 28 October 2011 at 1am

  9. JCW: to summarise the comments: put this up in the shop ;-)

    mharizanov 28 October 2011 at 1pm

  10. It looks like a resistive transformerless power supply, right ? Have you tried a capacitive also ?

    I like the JNµ Board. I use the Jee Nodes with Bascom-AVR anyway so I don’t care about sketches and so on. I just need an ISP connector, that’s it !

    MAK3 29 October 2011 at 8am

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