Observe ADC Functionality and Current Consumption in Data Visualizer

Open Data Visualizer by clicking the Data Visualizer tab to observe the ADC functionality and look at the power consumption, as shown in Figure 1.

Figure 1. ADC Data Print to USART Terminal and Power Analysis for ADC WCMP Mode

By rotating the potentiometer knob, the voltage input to ADC input pin, PB1, is changing. The ADC result is printed to the terminal only when it is below 80, which is the ADC window low threshold value. When the value is above that, ADC WCMP interrupt will not be triggered and hence no data will be printed to the terminal.

In the power analysis window, when looking at the current consumption, the average current consumption is about 1.18 μA which is slightly reduced from 1.32 μA in the previous assignment. This is because the ADC WCMP mode is now used. There are now two categories of the high peak glitches:

When the RTC overflow interrupt triggers to start the ADC conversion while the ADC result is above the ADC window low threshold value and the USART transmission is NOT performed. This is illustrated in the first half of the power analysis graph, with a current consumption around 240 μA. This has been reduced from constant 690 μA in the previous assignment at where no window filter feature is available.
When the RTC overflow interrupt triggers to start the ADC conversion while the ADC result is below the ADC window low threshold value and the USART transmission is performed. This is illustrated in the second half of the power analysis graph, with a current consumption around 690 μA. This is equivalent to the peak glitches in the previous assignment.

As shown, this application with implementing the ADC WCMP mode can reduce the peak current consumption, when the ADC result is out of interest and no USART transmission, is triggered.

Result: The ADC WCMP mode slightly reduces the average current consumption. It mainly reduces the current consumption for the scenario when the ADC result is above the window threshold value and no USART transmission triggers. The benefit varies depending on how often this scenario happens. Note that there are four different window compare modes available to fit the user's requirement.