Hi everyone,
We are using a MSP430FR2512 in our project in order to detect a touch on a metal base of a lamp, in order to switch the light or snooze the alarm. (We also use its PWMs to control the leds drivers).
I used the Captivate design center software (which is very nice to use btw) and proceeded to the first calibrations of the module in our system, which works pretty well on several of our prototypes, but the results are not consistent on all of them. It seems that there are some variations from one to another, maybe due to the mechanics involved in the measure (we use a simple copper wire, soldered to the PCB on one end, and stick to the base of the lamp via a copper scotch on the other end, perhaps the length and position of the wire can explain the variation between two protos).
Another problem that we have to face is that the sensor is triggered when audio starts to play from our speaker. For now, I'm just resetting the calibration when I detect more than 2 seconds of trigger, so that a real touch detection can be measured even if audio is playing, but this is only a quick fix, maybe there is a better option to choose.
We would be glad to have some inputs on those problems if it's possible.
Thank you in advance for your help, and have a great day.
Yoann