3.8.1 Operation

When Easy Tune is enabled, the thresholds are adjusted automatically based on the noise level on the touch sensors. The threshold is adjusted based on the current noise floor ranging ±50% of the threshold configured using the Channel Threshold (THRESHOLD) register.

For example, if the Channel Threshold (THRESHOLD) register sets the threshold to 50, the touch delta on the given sensor will be nearly 100 counts. The Easy Tune feature would vary the threshold between 25 and 75 counts for this configuration. Under no noise, the threshold value will be set to 25. As noise levels increase, this feature increases the threshold in steps of 10 counts for a maximum of 75. As noise levels reduce, the threshold value is reduced in 5 count steps.

While Easy Tune is enabled, the oversampling/digital gain ratio adjusts automatically for all channels, while a ratio of 8 is maintained. For example, if the oversampling is 16 and the gain is four, the oversampling is adjusted to 32.

Note:
  • The decision to enable or disable the Easy Tune feature can be determined during the development. Ideally,disabling the feature at runtime is not recommended. But if such a situation arises, all the buttons must be calibrated if Easy Tune feature is disabled at runtime.
  • The channel threshold (THRESHOLD) register will be reset to the previously saved value when enabling the Easy Tune feature at runtime