I have read How can a capacitive touch screen be triggered without human contact? and feel a bit closer to understanding the technology, but I am still a bit puzzled.
I recently picked up the task of making a new head-pointer for a client of a charity that I work for that modifies equipment for disabled people. They use this to operate an iPad-like device.
Their existing head pointer was a rugby scrum-cap with an aluminium plate riveted on, then an aluminium rod with an "i-Crayon" touchscreen poking device taped to it.
I made a new one using a rugby scrum-cap, a 3D printed plate sewn on, a carbon fibre rod and a 3D-printed holder for the iCrayon (so that other end-effectors could be fitted)
I used a small magnet to help hold the end-effectors on.
The client complained that it didnt't work very well and they blamed the magnet. They removed the holder, then taped the i-Crayon to the rod. They claimed this worked better. However the magnet remained in place on the end of the rod, so I don't think this was the issue. Also I don't think that this was the issue because I can think of no plausible mechanism.
I don't know how the i-Crayon works, it seems to be entirely non-conductive. The carbon fibre rod conducts end-to-end, at 45 ohms. (surprisingly) The 3D printed parts are non-conductive, at the moment. But I have some conductive filament to try.
An important point is that the client is in a wheelchair and is not holding the tochscreen device. I think it is mounted to the chair, or it might be in a stand next to the chair.
How can I make a device that works better for this client, in this rather specific setup?
