Jonathan Lopez

MPR121 capacitive buttons sensitivity overlay

Discussion created by Jonathan Lopez on Mar 18, 2016
Latest reply on Mar 30, 2016 by David Diaz Marin


I'm working with this IC (MPR121) and I have developed it with PIC32. Problem is I can't get the enough sensitivity I need. I tried to modify:

     - Threshold

     -Threshold release

     -Electrode size and form.

     -Even USL/TL/LSL following the right config.


I have worked before with Atmel capacitive buttons driver, even Microchip, and, better or worse (I preffer Atmel) I can get over than 3mm (even higher). With MPR121 I cant get 1mm.  If I push with much force, it detects (not always), but is impossible to get a correct capacitive effect.


I'm losing something? (about SW /HW MPR121). Is there a limitation in this IC?


I think the electrode/PCB HW is working perfect because I have tested this MPR121 with some prototypes that are working perfect with other drivers. Anyway, I have checked MPR121 with some specific electrodes to this task.


Thanks a lot.