I am developing interface with CPT112M and host controller.
Working of system is like, Host controller will remain in sleep mode and it get wake-up after detecting proximity event so that it will turn Keyboard back-light. When key is detected it will read and process. After some time host controller and touch controller will go in to sleep mode (or low power mode).
Presently I have observed that CPT112 is giving interrupt only after touch detection and not after proximity detection.But when I connect board with Simplicity Studio and check for proximity and touch status in "Capacitive Sense Profiler" it shows proximity status ON when I take finger close to sensor. Is it giving any interrupt or any other mechanism available to detect proximity event.
Kindly guide me to resolve proximity event detection issue.
Thanks & Regards,
I spoke with the developer for this part, and he mentioned that prox does not actually send an interrupt. It merely wakes the device up so that it can detect touches quicker, so the behavior you're seeing is normal.
Thank you for your support.
Please suggest the suitable IC which will have required feature of interrupt at proximity and also touch.
Please confirm is it possible in CPT212 IC.
Also please confirm that when I connect CPT112 evaluation board with Simplicity Studio and check for proximity and touch status in "Capacitive Sense Profiler" it shows proximity status ON when I take finger close to sensor. Please clarify how it gives information to "Capacitive Sense Profiler" .
I thought I had replied to this previously, but my reply doesn't seem to be here. To answer - all CPT devices with proximity detection use the same mechanism, and do not generate an interrupt on a proximity event. The reason Simplicity Studio is able to see this is that it uses the C2 debug interface on the device to read out the status of all of the sensors, including the prox sensor. It does this periodically, so it does not wait for an interrupt to occur to get the status.
Thank you for update.
Mean time I have purchased one CPT212 evaluation kit and conducted trials. It is observed that CPT212 gives/generate interrupt after detecting proximity and after touch also.
Kindly confirm the same.