6 BEMF Acquisition Demo Results

Below are illustrations of logic analyzer captures that show the sampling moment of BEMF during the dead time and how the sampled BEMF follows the driving signals of the motor’s phases:

Figure 6-1. Sampling Point of BEMF During Dead Time
Figure 6-2. Sampled BEMF for One Phase of the Motor. Analog Comparator Output Vs. Sampled BEMF
Figure 6-3. All Three Motor Phases with their Sampled BEMF Signals.

In this capture the phase signals are filtered with a hardware low-pass filter to observe the sinusoidal drive.

Here, one can find an MCC-generated code example for AVR16EB32 with the same functionality as the one described in this section: