SLAU857A May   2021  – July 2021 MSP430FR2476 , MSP430FR2512 , MSP430FR2522 , MSP430FR2532 , MSP430FR2533 , MSP430FR2632 , MSP430FR2633 , MSP430FR2672 , MSP430FR2673 , MSP430FR2675 , MSP430FR2676

 

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5.4.4 System Reliability Parameter Adjustment

The adjustment of system reliability parameters mainly reduces the influence of noise from the perspective of software and handles abnormal modes. The functions involved in this part are shown in Table 5-7, and the numbers in the selection boxes correspond to those in Figure 5-13.

Table 5-7 System Reliability Parameters
NumberOperation FunctionRecommended ValueComment
8 Modulation Enable Set frequency jitter function. Can be disable For the self-capacitive mode, the frequency jittering function is enabled, and the mutual-capacitive is not enabled.
9 Pro/Touch Debounce In Threshold Set the delay time for the system to determine the occurrence of proximity sensing or touch events. 1-3 Response delay is in Active Mode Scan Rate ms.
Pro/Touch Debounce out Threshold Set the delay time for the system to judge that there is no proximity sensor or touch event. 1-3 Response delay is in Active Mode Scan Rate ms.
Sensor Timeout Threshold Set the time for the system to reset calibration when the proximity sensor is triggered continuously. Set according to time requirements The time is in Active Mode Scan Rate ms, which can prevent continuous forward signal drift caused by environmental changes.
Negative Touch Threshold Set the threshold for the negative change of the equivalent "Count" value of the capacitor. Default value The threshold value of the absolute change of the touch signal can prevent the negative signal change problem caused by touch power-on.
Counter Filter Beta Set the strength of IIR filtering for the equivalent "Count" value of the capacitor. 1-3 Too much assembly affects the response speed.
LTA Filter Beta Set the strength of IIR filtering for LTA. 7 Changing this size can cause unresponsiveness after multiple touches.
Error Threshold Set the maximum value of the charge conversion output. conversion count × 1.25 Increase the processing logic according to the flag bit bMaxCountError.

Noise sources include the CapTIvate module itself, digital signals in the MCU, the power supply, and the input signal at the capacitive touch pin. Reasonable parameters can reduce the impact of noise, but they often need to be adjusted repeatedly. The objects of repeated adjustments are mainly "Pro/Touch Debounce In Threshold" and "Counter Filter Beta" functions. At the same time, make sure that the noise Immunity function in the MCU widget is enabled.