LAUNCHXL-CC26X2R1: Touch Sense false events

Hi TER, 

Thank you for the response . we tried changing the source current as suggested.

We have arrived at a source current which looks good for our product. We still have issues with false events rarely and when kept near metal pieces ,

The tdc raw value seems to increase beyond the  threshold  and get false triggers. we observe this after keeping the device  for charging.(battery powered device) also.

We have a metallic display near our touch contact points  and we use a metallic pad above the touch point on the top case cover. 

Does these affect the tdc raw value to increase slightly? How could we get rid of this interference and false events. ?

We tried to process touch detection only in  case of raw values 5 more than threshold, but this doesn't help for all devices as some become non- sensitive with this adjustment.

Thank You,

Anu

Yes, we use the example from SCS and altered the source surrent to 5.5uA which was found better for our boards. 

We will try considering a dummy button as you have mentioned above. 

In the sample from SCS, when we found for a touch button , when the tdcraw value is somehow high to 8194. At this point the baseline value or threshold , nothing is getting updated. All shows 0 .Why is that no value updation in case of such large tdcraw value. ?

We used the SCS capacitive touch sample and changed the source current to 5.5uA. 

On touching the contact button directly, we get the scs graph as below:

And on touching with the plastic case above , and a mesh foam above the contact point on the cover , we get the below graph in scs:

Does these graphs looks okay ? Do u have any reference images of the graph from  SCS.

The Simple Link Academy Cap Touch training (http://dev.ti.com/tirex/explore/node?node=AA.yCLw0Wp14vqtq.uXpmw__eCfARaV__LATEST) has some graphs.