Autotune for CVD Devices
There are differences in how the touch library is managed for Charge Voltage Distribution (CVD) and Peripheral Touch Controller (PTC) devices. To simplify the tuning process for the CVD waveform, the library offers auto-calibration for acquisition time and additional internal capacitance. This auto-calibration is performed for each sensor following power-up, timeout, and negative capacitance detection events. For more information, please refer to the "Auto-Calibration" section of the Hardware Sensor Configuration page.
When the auto-tune and touch-tuning options are enabled, we will observe varying values for acquisition time. Below is the screenshot that displays the different acquisition times when these options are enabled.
For production, you can directly use these tuned values in the code generated from MPLAB® Code Configurator (MCC). Below are the steps in detail:
Select Enable Touch Tuning Data Connection and Enable Charge Time Autotune.
Enable Touch Tuning Data connection provides two options, one being Touch Tuning (bidirectional, requires UART Tx and Rx).
The other option is Touch Visualization (unidirectional, requires UART Tx).
When Enable Charge Time Autotune is selected, you will notice variations in acquisition time and additional internal capacitance, as highlighted in the image.
In MPLAB Data Visualizer, note down the acquisition time and additional internal capacitance value.
Use the obtained values in production code and disable the touch-tuning option.