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PI CAP - Crocodile clips won't stop triggering

Hey!

I just connected a crocodile clip to the PI CAP and noticed that when the metal of the clip touches the PI CAP it instantly triggers it - and it stays in that state. How do I work with crocodile clips? Do I need to connect the ground to something special? I tried to put a croc clip to GND and connected that to my heating radiator - it didn't change anything.

Using the picap-intro touch-mp3 patch.

Jan Answered

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Hi Jan

Thanks for getting in touch. Attaching a crocodile clip to the Touch Board increases the capacitive load on that electrode which looks just like a touch that never goes away - hence the behaviour you describe! If you restart the code after adding the crocodile clip this will recalibrate to the additional static loading.

Another bit of useful advice is to keep the croc clips stable when they are attached - motion relative to one another changes the static capacitance too, which can cause false triggering. As always, restarting the code recalibrates.

Hope this helps!

Bare Conductive 1 vote
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Okay, restarting seems to be working! But I guess crocodile clips is not really that stable since a micro motion will result in false touches (that stay) or in other unwanted behaviour (not every touch gets recognized).

Can you give a recommendation for a more stable connection? Soldering cables directly to the Touch Board?

Jan 1 vote
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If you are using the Touch Board, you can solder headers onto the 0.1" pitch pads along the right-hand side of the board labelled with the electrode numbers. You could also solder wires directly onto here if that's more convenient, although headers allow for disconnection and reconnection more easily. The Pi Cap does not feature these pads, so this connection method is not applicable for that product.

Alternatively, you could bolt a wire with an M3 ring crimp (https://is.gd/m3_ring_crimp) at the end directly to the board if you are using either the Touch Board or the Pi Cap. Be careful to ensure that the ring crimp does not touch the neighbouring electrode when doing this.

Bare Conductive 1 vote
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When I bolt a wire with an M3 ring crimp to my PI CAP then I will be able to use long wires connected (i.e. soldered) to the other end of the ring crimp?

Thanks for helping out! Looking forward to trying that out!

Jan 0 votes
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Yes you should be able to solder wires onto the crimps, you might want to use shielded cables if they are very long wires, and ground the shielded section of the wire to ground.

Bare Conductive 0 votes
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