Pardon me for creating this thread, but I want to capture this great discussion in one topic.
Hopefully it won’t fizzle out after this.
2 Likes
1 Like
yup, that fizzled… only one poster on the first page 
1 Like
@ Brett - I guess that’s how it goes. Well I got a bunch of it corralled into one thread so we can come back to it. I would have never remembered to search for a thread named dark side of tech.
2 Likes
Wechselstrom Messwandler?
I had a messwandler once, but I got a prescription.
The board I posted about doesn’t have a VCC output. It has a 3.3 or 5V input for powering the opto-isolators so I use an Itead Studio 5V 500mA AC-DC to power the ESP12 module I use to talk to this board. In fact, I have found that to use 3.3V you need to change a resistor but I couldn’t get reliable comms this way so I power from 5V and use two BSN20’s to do the level conversion to 3.3V. Works perfectly this way.
https://www.itead.cc/power/other-power/ac-dc-power-module-5v-500ma-v3.html
These are very well made and they have good AC-DC isolation.
I used a Nextion display from Itead to give me a local readout of the voltage, current and power. The image below doesn’t have the costs display. I’ll update later when the unit is built and installed.
4 Likes
My current system uses one of those. The new board using the PZEM004 has ultra stable readings and can measure 1W quite easily. And price wise you get the clamp and the measuring circuit for a little more than the above clamp alone. 
I could never get the AVR to be stable enough.
1 Like
Dave, the only link i see is one to refernece another like type device. Can you give a blind man a hint where its at 
Try this. It was on the link to the other module (one without the split core)
This will give you a ZIP file which contains the Windows software and a Word document on the protocol.
1 Like
Thanks Dave! But those files do not contain a pinout.
It does for the 4 pin TTL serial port.
The other connector is not documented. I suspect this is used for internal programming and testing.