I2C Current Monitor (PR29-2_20A) doesn't show up in RPi (i2cdetect)

Hardware
1

Hi guys, my first RPi project…using the PR29-2_20A single-channel CT current monitor board connected via I2C to a Raspberry Pi 3. I’m following the tutorial here: https://www.hackster.io/ControlEverything/energy-monitoring-through-a-raspberry-pi-190a2a

Anyhow, everything seems to be going well…up to the point where I use “i2cdetect” to show the address of the board. If all went well, should show up at address 2A. However, this is what I see:

pi@three1:~ $ i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – -- – -- – -- – -- – -- – -- –
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- – -- – -- – --
30: – -- – -- – -- – -- – -- – -- – -- – --
40: – -- – -- – -- – -- – -- – -- – -- – --
50: – -- – -- – -- – -- – -- – -- – -- – --
60: – -- – -- – -- – -- – -- – -- – -- – --
70: – -- – -- – -- – --
pi@three1:~ $

So…nothing. Board is connected and powered using the proper stock power supply. Connected to the pi via the supplied I2C cable. At first I was connected to the “I2C OUT” on the board and that didn’t work. Then I tried the “I2C IN” with the same result. Red light is on on the board. Is it possible I have a bad board? It’s new out of the box. Thanks!

2

Just throwing this out there…could it be my i2cshield? I purchased the shield for the RPi Zero. However, being a N00B, I didn’t realize until I tried to hook it up that my zero w had no i2C prongs, so I tried it on a Pi 3 instead. I have ordered the I2C shield for the 3, but that won’t be here for a bit. Wondering what the difference is for the zero/3 shields??

3

Hi,
Seems like you have everything connected as it should.
could you post a picture of the setup?

Thanks

4

image
image.jpg1537×968 400 KB

Now I think I may have had the connector on backwards (they’re orientation independent, who knew!) Pin 1 is marked on the shield, and I looked up the pi orientation. Now that I think I have it on the proper way, still nothing. The pic is using the I2C “Out” port, but I also tried the “in” with negative results…I hope I didn’t fry something :frowning: .

5

on the current monitor board the cabe needs to connect to the I2C IN port.
is it a PI3B+ or Pi 3?

Thanks

6

Thanks. Yep, I tried the “IN” port also. It is a Pi3B. No “Plus” sign I can see anywhere on the packaging.

7

did you enable the i2c in raspi cgf section?
You will need to enable the hardware i2c and reboot that pi.

8

Yep, it was enabled.

9

Strange!!!
do you have any other Pi you can use for a quick test?

10

Right now only the zero, which has no pins on the GPIO ports, so I can’t figure out how to connect the I2C shield to it (even though the shield was designed for a zero…?). Anyhow, I’ll try that other shield (designed for the 3) once it arrives; if that doesn’t do it, I’ll pick up another 3 and try that. Still afraid I fried something by putting the shield on backwards. But I can find no mention of this anywhere on the interwebs, and you wouldn’t think I’d have been the first maroon to ever do that…

11

I did track your order build sheet and it showed that all the parts were tested and working before shipping.
Lets try with new shield and new pi. if it still does not work you can send it for repair.

Thanks

12

Woo Hoo! I didn’t even realize you were affiliated with the company! (I actually typed a thank you earlier this week but now I see I never hit reply!)

So the new interface is here. New Pi. AND:

pi@raspberrypi:~ $ i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – -- – -- – -- – -- – -- – -- –
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- 2a – -- – -- –
30: – -- – -- – -- – -- – -- – -- – -- – --
40: – -- – -- – -- – -- – -- – -- – -- – --
50: – -- – -- – -- – -- – -- – -- – -- – --
60: – -- – -- – -- – -- – -- – -- – -- – --
70: – -- – -- – -- – --
pi@raspberrypi:~ $

It’s showing up! Thanks for your help! Gonna try the original RP3 to see if it’s the unmatched interface board or if I fried my original RP3. Thanks again!

p.s. Before I forget, since you’re with the company: The original interface board I bought is supposedly for a Zero. But my zero has no GPIO prongs! Is that a function of my specific Zero, or is there something else I need to connect the interface to a zero? Thanks again!

13

You can use the pi zero shield with Pi zero. no extra component needed. I dont use Pi zero, i prefer using Pi3 or above. it has Ethernet and other ports, which makes debug and testing much easier.

Thanks