AC Current Monitor -> IoT -> I2C -> RPi3

I bought the “2-Channel Off-Board 98% Accuracy AC Current Monitor with IoT Interface” (100 Amp; SKU: PR38-16_100A) so I could monitor my whole home energy usage.

I have a Raspberry Pi 3 that I want to use do some python development and monitor energy usage running Raspbian Stretch.

To get the RPi3 and AC Monitor to work together, I bought the “I2C Shield for Raspberry Pi 3 & Pi2 with Outward Facing I2C Port Terminates over HDMI Port” (SKU: PR2-3) and the “I2C to IoT Interface Adapter” (SKU: PR37-3).

I got the I2C Shield working on the Pi with another I2C device (OLED screen), so I know that works, but I when I plug the I2C to IoT into the AC Monitor (not sure if it correct) and connect that to the I2C interface on the Pi. i2cdetect -y 1 does not show any devices, when it worked with the OLED screen.

Anything, that I could be doing wrong? Wrong adapters? Wrong insertion of the IoT to I2C?

Thanks for your help.

Do you have power supply connected to the current monit board?


Nope, that would do it. I knew I was doing something stupid.

I have a 12 VDC power supply already nearby, so I will do that.