Other Parts Discussed in Thread: CAPTIVATE-PHONE,
Hello,
I am using MSP430FR2633 TSSOP package controller for 16 elements keypad sensor for touchpad. I am using mutual capacitance technology for this purpose. I have followed the hardware layout design of CAPTIVATE-PHONE. Though I am able to detect the finger touch on keypad, I observed that on frequent touching of keypad elements, suddenly touch detection is stopped. However after waiting for few seconds, it starts the detection. There is acrylic overlay of 2 mm over the captouch.
To add the information, my keypad is powered by SMPS(AC to DC) which is further powered by UPS. SO, we have observed that whenever we removes UPS supply , keypad captouch works fine, it only creates issue when UPS comes in the picture. We have already enabled Noise immunity feature in the firmware. Though we had not included capacitor of 68 pF at RX line for EMI filter initially, we put it on RX line after some adjustment on PCB. Please help us to resolve this issue.
Thanks and Regards,
Omkar