What does a controller do?
The touch sensor emits an analogue signal that changes whenever a user is interacting with the device. Also, this analogue signal does not include any easy-to- understand information on how the user is interacting with the device.
What we need is a device that transforms the analogue output of the touch sensor to useful information that gives insight on how the user interacts with the device.
This is exactly what a controller does. A controller receives the analogue signal from the touch sensor and transforms it into useful, digital data that give us an idea of what the user is doing. This data can then be used by the operating system of our
device, to trigger actions that appropriately respond to the actions of the user This digital data the controller uses is often called counts.
Despite their popularity, designing functional capacitive sensors still remains a challenge. One of the most challenging parts of the process is integrating your touch-enabled device with a microcontroller - or simply a controller.
Since information regarding this aspect is scarce and confusing, especially for beginners, we have compiled this guide which will help you navigate through the Integrated Circuit (IC) manufacturers’ documentation about controllers.
We will discuss the main parameters you will face when tuning a controller and then we will take a look at the various specs IC makers promise their controllers have, what they mean, how they work and ways to improve upon them.
Common Tuning Parameters
Drive Signal Time
Sense Signal Gain
High Level Controller Properties
Noise Robustness & SNR
Get our free guide about Controllers for Capacitive Touch Sensors here