It's my first time using a touch sensing chip, such as the QT110. I am attempting to make the outside of a "monome" style button touch-sensitive.
The image shows my current setup with an arduino.
I am currently unable to get the setup to work. When I touch the wire, it works just fine. But even when I coil the wire into the button, it fails to create a proximity field outside the button.
Any thoughts? Help? thank you!
I forgot the specifics...
Do you need to coil the wire? Presumably if it is going to be touch sensitive then the wire does not need to 'make a button'.
Mowcius
I am trying to make the outside of the monome button, touch sensitive. I need to know when the button is being touched, before the button is pushed down. 
Ahh, well presumably you could use the button that is already on the monome and then add in the touch sensitive bit not in a coil. I presume that the coil interferes or something...
Mowcius
Yes, I do plan on using the monome button too. I think I need to adjust the capacitor in the connections. Even without the coil, I tried a .47 uF and a 15 nF capacitor, and both only allowed a touch to activate it. I will try much larger and smaller capacitors tomorrow to test again.
Ok, I have only ever done touch sensing using the capsense code and a resistor so I don't really know about that without looking into it.
Mowcius
I saw that capsense library. How easy was it to use? Is it possible to control the size of the touch field, with some accuracy? What size resistor did you use?
Well I used it before it was a library and it was very easy to use. I have not used it since but it seems to have gained complexity (so it can do more no doubt).
I used a range of different resistors giving a range of sensing. I found that low ones (hundreds) worked for close or touching (analog reading so you can take values from almost anything - not just on or off) and I used high ones (thousands and more) to sense much larger distances from a few cm to a few metres!
You just have to play with the values and a few pots to see what you get!
Mowcius
Just spent some time with the capsense library, and many tweaks of resistors...
I can see that the library is doing something, but the values are so erratic and unpredictable. I tried 3M to 10M in resistors. 4M works somewhat ok now. The values are up and down so quickly though. Sometimes the values start compounding over time too. I wouldn't know what value range means a "touch" and what range is not a touch.
Will try more experimenting...
Ok, as I say, I have not used it for ages but when I used it before it was a library I don't think it was that eratic. Are you testing with your coil or a length of wire?
Mowcius
I was just testing with the straight wire.
Thanks for the responses! I will be testing more soon, with local experts. Will post updates.