Kasbah posted an update on his Nomech mini project we covered we previously:
So after some wrangling with the code I got the charging and discharging of the sampling capacitor working. CH1 is the slope pin which is used for discharging the sample capacitor (and then measuring the time it takes to discharge ).
These are the pulses on the drive side. This is what the bottom of the sampling capacitor looks like. You can see it charge up and then discharge when the slope pin goes high. Eventually I got the AVR interrupts to work and could actually measure the time to zero crossing. I took some measurements which I can use as a baseline as I add components and change the code. But there you have it. It is sensing touch so I am pretty chuffed! I am yet to discover how robust it is. Code is up on github too