Capacitive Touch HAT doesn't work with alligator clips

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thisisjohnbrown
 
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Capacitive Touch HAT doesn't work with alligator clips

Post by thisisjohnbrown »

I have my HAT soldered up, connected, and code running on the Pi. If I run my finger along the HAT's alligator clip area, I get a response perfectly.

But when I clip on alligator clips, it will engage the sensor and never stop. So each sensor is running "high", and can't detect further interaction with the clip or anything attached to the clip.

Could I have made a mistake in soldering? It works perfectly with just finger touches.

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drewfustini
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by drewfustini »

Please post a photo showing your hardware and connections and we'll take a look. 800x600 images usually work best.

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redwoodturner
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by redwoodturner »

I have exactly the same problem - using with a Pi2.
Board works perfectly withe touch, but any conducting items such as a croc clip causes the response to repeat until the item removed.

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adafruit_support_bill
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by adafruit_support_bill »

@redwoodturner - Please post some photos showing your soldering and connections. 800x600 is a good size.

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redwoodturner
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by redwoodturner »

It's a HAT. What other connections do you expect? If you are suggesting it is a dry joint please let me know. What was your reply to the first person who queried the problem please?
derek

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adafruit_support_bill
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by adafruit_support_bill »

What was your reply to the first person who queried the problem please?
We made exactly the same request as you can read above. The OP has not responded.
Please post a photo showing your hardware and connections and we'll take a look. 800x600 images usually work best.
The vast majority of problems are soldering related. We like to start with a a good view of the board.

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redwoodturner
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by redwoodturner »

Okay.
To reduce the possibilities, I have reduced it to a headless set up with only the power supply and headphones connected. As before the touch connections all respond correctly to a human touch, do not respond to an insulation touch but remain in a permanent loop when a conductor including a croc clip connected to any of the 12 connections. I attach a photo as requested.
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P1040753-00.jpg
P1040753-00.jpg (151.5 KiB) Viewed 346 times

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adafruit_support_bill
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by adafruit_support_bill »

What are you connecting to the inputs and how long are the wires? The sensitivity of the input is roughly proportional to the surface area of the attached conductor - including the connecting wire. Large objects or long connecting wires can make the input hyper-sensitive to the point where it becomes unstable.

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redwoodturner
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by redwoodturner »

I've tried: a double ended croc clip lead 6" long, a scredriver with 6" arm and a single wire 2 " long.

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adafruit2
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by adafruit2 »

each object has some capacitance and the hat does calibration when you first run the software. so you can't 'live' connect stuff. you have to connect everything and *then* run the software. that way the capacitance of the cables is taken into account :)

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redwoodturner
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by redwoodturner »

Solved - great, thanks for this. Can't say that I understand what is going on mind you!
It might be useful to add this as a note in the tutorials for the hat.

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adafruit2
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

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rhydutsky
 
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Re: Capacitive Touch HAT doesn't work with alligator clips

Post by rhydutsky »

Hi sorry for no responded sooner. It was software, the additions to the tutorial are crucial thanks for adding them.

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