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CE229279 CapSense Custom Scan | Cypress Semiconductor

CE229279 CapSense Custom Scan

Last Updated: 
Mar 26, 2020

Custom scanning provides fine control over sensor parameters and helps in adjusting the sensitivity for various sensors within a widget. Custom scanning of CapSense sensors might be required for some very specific applications such as:
1. Changing the inactive sensor connection based on the sensor being currently scanned
2. Setting different tuning parameters for various sensors within a widget
3. Optimizing the sensor performance by disabling source of noise when the affected sensors are being scanned

This example demonstrates the custom scanning capability of CapSense using callback functions with the linear slider implementation. In this code example, sensors which are near the sensor being scanned are connected to the shield, while other sensors are connected to ground. This provides liquid tolerance and reduced parasitic capacitance of the sensor as well as the shield. It also decreases emissions because the entire slider segment is not always being switched with high-frequency shield signals.