Continuing from the old thread ( http://arduino.cc/forum/index.php/topic,22640.0.html )
Alright, so I'm back :)
A few things:
- The counters don't appear to share a common ground.
- I'm pretty comfortable with soldering, just not very comfortable at creating circuit designs :) As long as I have smart people like you to help me through, "rolling my own" opto-isolators sounds like something I can probably handle.
These meters appear to have additional outputs that sound pretty promising. They are:
"10, Isolated Output (10 Wh/P, Kh = 10)" Definition: Isolated pulse output: 5 watthours on, 5 watthours off, reference to ISOL COM NOT TO BE USED FOR FIELD WIRING
"100, Isolated Output (100 Wh/P. Kh = 100)" Definition: Isolated pulse output: 50 watthours on, 50 watthours off, reference to ISOL COM
"1000, Isolated Output (1 kWh/P, Kh = 1000)" Definition: Isolated pulse output: 500 watthours on, 500 watthours off, reference to ISOL COM
"ISOL COM" Definition: Isolated common for 10/100/1000 isolated outputs
Now, this sounds promising! I've emailed the people who make this meter to ask them what voltage the isolated outputs are giving out. If it's 5V would that mean there is no need for opto-isolators?