7.1 Preparation

Front Panel

Front Panel should securely adhere to the sensor PCB (Printed Circuit Board).
There shoud not be any air-gap
- Air-gaps causes unit-to-unit variation.
- Reduces sensitivity significantly.
- Causes unpreductable touch behaviour.
The assembly should be representative of the final product assembly. If not, retune may be required for production.

External Resistor

Refer to the following table fo initial series resistor configuration should be used for tuning. If targeted noise immunity is not known, select the based on the power supply.

Note: The resistor value may need to be chagned during noise tuning.

Table 7-1. Recommended Resistor Value
	Self-capacitnace	Sel-capacitance + Driven Shield	Mutual Capacitance
Targe Noise Immunity (Conducted Immunity)
High (10V)	100KΩ	50KΩ	1KΩ (100KΩ internal)
Medium (3V)	50KΩ	10KΩ	1KΩ (50KΩ internal)
Low (1V)	1KΩ	1KΩ	1KΩ (0Ω internal)
Power Supply
Battery Operated	1KΩ	1KΩ	1KΩ (0Ω internal)
Mains Power Supply	10KΩ	5KΩ	1KΩ (10K internal)

Power Supply

The initial touch tuning, such as charge time, sensitivity etc., must be done a stable power supply.
Use a bench suppy to power the device until basic tuning is completed.

Project Generation

For tuning the touch sensor, it would be good to have a project with just the touch application and tune (debug) data available on the Data Visualizer.
Refer to Generate Touch Project with MCC Melody for generating touch project for 8-bit or 16-bit MCUs.
Refer to Generate Touch Project with MCC Harmony for generating touch project for 32-bit MCUs.
Refer to Tune Touch Application Using MPLAB^® Data Visualizer for information on viewing touch tune data in MPLAB^® Data Visualizer.
While creating the project,
- Configure the touch pins.
- Configure the debug pins.
- Enable Sensor Charge Time auto-tune option.
  Note: Not all devices support auto-tune feature. In such cases, refer to manual steps decribed in charge tune section.
  Note: Auto-tune charge time option must be used only for the initial development. When the tuning is completed, and when the system is ready for testing, the auto-tune option must be disabled and manual feed values must be used.
- Enable Frequency Hop auto-tune option (if Target Noise Immunity is medium or high).
- Keep the other parameters to default values.
- Download a copy of the project with the Sensor Charge Time auto-tune option disabled.