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PSoC 4 MCU

New Contributor

Hi ,

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?

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4 Replies
Moderator
Moderator

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?

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New Contributor

Hi ,Lingling,

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

pastedImage_0.png

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Moderator
Moderator

Hi Jack,

你这个问题我怀疑和调试的capsense的参数有关系。请重新调试参数,噪声阈值,手指阈值,和迟滞。

你截图的信号状况,是否是每次点击都能复现?

没有手指触摸的时候,rawcount和baseline是否是重合的?

如果是否不触摸,是否会有误触发的现象发生?

目前你sensor的是多少位得扫描分辨率?

Thanks,

Lingling

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Moderator
Moderator

Hi Jack,

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?

Thanks,

Lingling

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