I thought this would have to go in the homework topic, but its not really homework its more off a project - so I posted here. :P I need to do a project for my physics coursework involving sensors and it can be pretty much anything as long as it involves sensors. I've been stuck for ideas (all the obvious ones have been taken and everyone has to do something different) and my teacher said to look into QTC pills and maybe do something around there. I really just can't think what to do... Anyone have any ideas what I can test with a QTC pill (oh yeah, it has to be related to a practical problem too)? Here's an example of what someone has done: have different frequencies of a sound and keep it at the same volume. Put a microphone near it (with an oscilloscope) and see if different frequencies produce different results. Or testing an LDR with different coloured light at the same intensity. Thanks in advance, Rich. EDIT: how do these pills actually get used in a circuit? How do you include them?