CPT112 - capacitive touch controller from Silicon Labs

A project log for Tactile Remote Control of a Mobile Device

Control your mobile device remotely without using the touch screen

kyle-thomasKyle Thomas 10/07/2017 at 16:120 Comments


The CPT112 touch processor can support up to 12 capacitive touch buttons, but can also be used to support a single capacitive touch slider, which is how it will be used in this application. 

The touch slider was layed out using the kiCad footprint wizard, which can automatically generate capacitive touch sliders.  The slider on this board is 5 segments. 

The CPT112 needs the following connections:

CS01-CS05:  Connections to each of the 5 capacitive touch segments.

CNFG_CLK, CNFG_DATA:  Connects to the programming header

I2C_INT, I2C_DATA, I2C_SCL:  Connects to BGM111 with use of pullup resistors.

This part of the project will have its own log post later, describing the progamming and firmware required to support the chip.  The chip itself is pretty easy to use since it is I2C capable, but getting the capacitive slider to work the way i wanted took a fair bit of time!