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