questions

[UseIn02]

This is actually my first ever project so I have literally no experience. So sorry if I am asking things that are obvious.

-Is there a difference if I use 3 sensors rather than 4? what are the benifits?
-How can I power the LED strips with external power? Can I just hook up the LED strips with an external power and just hook the DIM pin to the pico?

this is the external power that came with the LED strip

[ravinrabbid]

The 4 MPR variant is mainly for the slider pcb since there were some restrictions regarding the board layout. In theory it is a bit more robust because the traces to the MPRs can be shorter, but in practice I did not notice any difference.

I'd avoid the external power supply if you can, simply for convenience. If the USB port does not provide enough power for your LEDs I'd first reduce the brightness in the firmware settings. I you then still need external power, only connecting DIN should work. Also connect both GNDs then. You might also need level-shifting for the data signal because the external voltage could be a bit higher. But if you are still unexperienced be careful since you could fry you Pico and/or USB port.

[UseIn02]

ohhhh so I get it now you have to phisically cut the wire on the back with a knife or some sort. I didn't even consider that there was a seperate GND for the ADD on the back thanks for the detailed answer!

[UseIn02]

Got the i2c bus figured out... At least, I think.
The sensors work nicely, but there is a new problem
https://github.com/user-attachments/assets/89c273fd-aeb0-4a5b-97fd-c1787b9d6927
As in the video, all the sensors work, even the flickering middle one. But in the middle, it is flickering like crazy is there a fix for this, or is the sensor broken? I bought more sensors just in case the problem is just a broken sensor.

[ravinrabbid]

Hmm, are there any data wires under the flickering part of the sensors? A broken sensor is possible, but unlikely ... maybe still replace it just to make sure.
In general keep all other wires away from the electrodes as well as the wires to the electrodes, also try to reduce overlap of the wires. Further I'd recommend to mount the sensor bar to a surface so that it cant move, since movement will also change the capacitance and could create false inputs.

[UseIn02]

update on the sensor. I had one left so I replaced the middle MPR and it finally worked smoothly I guess I burned the chip while I was soldering the middle one. Thankyou for all the help I just now have to get a housing for the controller. Thankyou again for all the help

[ravinrabbid]

Glad it works now, enjoy :)

[UseIn02]

Update on the controller I was building. Made some improvments on the pico side and made the copper tape 15mm. buttons work like a charm but having some trouble with the slider.
It doesn't seem to register correctly. I assume it is because I have 3 MPRs and have to edit the code to work any suggestions?