I have a QT1070 in I2C (Comms) Mode. I have connected a copper pad to the KEY4 pin (using suggested minimal trace width and 10k resistor near to the device).
I read out the NTHR value and key value. NTHR: 745, Key value reaches 800 when touched. It seems that when I touch the pad for the first time, it registers a touch (at approx. 790) but when I touch it again, the reading may go up to 810 but it doesn't register another touch.
I am contemplating just doing a comparison in the AVR MCU myself, but that would mean that I cannot use the CHANGE pin.
Any help / pointers would be greatfully appreciated,