I opened up the black box that connects to the current-sense transformers
included with The Energy Detective (TED) power monitor kits.
it contains a CS5460 chip which is a "Single Phase Bi-Directional
Power/Energy IC" which has a digital (SPI) data interface. Unfortunately
it does not have analog outputs, so it can't be used to convert the AC
current signals coming into it into a simple DC analog value.
http://pdf1.alldatasheet.com/datasheet-pdf/view/230848/CIRRUS/CS5460.html
however, if someone finds a nice arduino library to talk to this chip, we
can...
wait no, that's pointless. the chip is connected to a PIC16F627A which is
processing the data from the CS5460 and then sending it out over the power
lines using a TDA5051AT "Home automation modem" chip:
http://www.nxp.com/documents/data_sheet/TDA5051A.pdf
"The TDA5051A is a modem IC, specifically dedicated to ASK transmission by
means of the home power supply network, at 600 baud or 1200 baud data
rate. It operates from a single 5 V supply."
it transmits Amplitude Shift Keying (ASK) data transmission using the
electric power lines it's connected to. basically it communicates at
8.48MHz (somewhere between 6.08 - 9.504 MHz) in binary serial
communications. so it should be pretty easy to figure out what it's
saying.
It could be that the box that the current sense transformers plug into
just sends data (including its serial number, which is on a barcode label
stuck to the box) and a displaybox (or our hack) picks it up or not. But
it's also possible that it waits for a displaybox to transmit a signal
telling it to turn on, or asking it to supply a measurement on-command.
since we have displayboxes and these current sense boxes, we can find out
if we want. and then we can measure power flow throughout the omni.
-jake