Cheap MPR121 - disconnect ADD from ground?

D

Dazzer1234567

Member
Hi folks,

I picked up some cheapo MPR121 boards from Amazon, but now the chickens are coming home to roost because I've discovered that they tie ADD internally to ground (why?!), meaning i can't put several of them on the same 12C bus.

Claude is telling me they have a trace that i can cut through in order to disconnect ADD from GND, but looking through my magnifier, i just don't see it.

Does anyone know if it is indeed possible, and if so, where i should score through to cut that trace (that i can't see!)

Here's a pic of the board, and also the link to the product.


Thanks, hopefully, in advance!
 

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Make a cut shown in red.
After the cut check with a multimeter to see there is no continuity to GND.

Cheap_MPR121_-_disconnect_ADD_from_ground____Teensy_Forum.jpg
 
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OK, thanks!

And after that, I hook ADD up to one of the other pins in order to set its address at start-up, right?

Also, can you tell me: what are the two solder blobs to the either side of the trace you indicated (indicated with the green arrows in the pic below)?
Is there a component underneath these? I mean, do I need to be very careful when cutting the trace, so that I don't damage these two blobs?
 

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