We use the CY8C4146AZI as the touch chip in our handset. But recently, we meet many problems.
It is always have key stuck problems.
They may show the following phenomena.
(1) Some key were always triggered after powering up even though you didn't press the touch key in some handset.
(2) Some key may be always be triggered after you figure leave the touch sensor in some handset.
(3)In this phenomena,it shows unstable feature. Sometimes, I touch the key of the handset, it may have key stuck issue which described before.
And then I read the values of the touch signal, it is much bigger than normal situation. When your figure leave the touch sensor, this signal is
also bigger than normal. In the normal situation, if you didn't touch the touch sensor, the corresponding touch signal value should be zero.
But sometimes, it may seems as a normal handset. In this situation, all the touch sensor can work normal. And the value of the signal is also
in normal rang. What cause this problem? And what should I do to solve this problem?
1: Try to tune your sense in lower sensitivity, then check whether it will happen again?
2: Use " CyDelay(1000);" when code enter in main loop, check the phenomenon?
3: Attached the rawcount screenshot when you finger left the board?
You can see the signal and baseline information of stuck key as below.
From the picture, we can see that when your figure leave the touch sensor, the raw count data can't drop to baseline.
If you press touch sensor, the signal also increase. It also means the baseline is little small after you powering up
I suspect that this question has something to do with the parameters of the debug capsense.
Please re-commission parameters, noise thresholds, finger thresholds, and hysteresis.
Is the signal status of your screenshot re-emerged with each click?
Is rawcount and baseline coincident without finger touch?
If not touched, will a miss trigger occur?
How much bit of scanning resolution do you have at the moment?