Recognition of Mini trimmer potentiometer

   Further analysis of the right waveform and expansion along the time axis shows that although the left-handed and right-handed waveforms of the pulse Mini trimmer potentiometer are the same. However, in left-handed state, foot 1 first becomes lower than foot 2; in second state, foot 2 also becomes lower; in third state, foot 1 first becomes higher than foot 2; in fourth state, foot 2 also becomes higher; when the pulse potentiometer is right-handed, the output waveform of foot 1 and foot 2 changes exactly opposite to that of left-handed. Therefore, it is possible to distinguish whether the pulse potentiometer is left-handed or right-handed according to the time identification method (comparing the time difference between P1.0 and P1.1 when low level occurs and ends). In dynamic scanning, it is difficult to measure the waveforms of P1.0 and P1.1 because of the influence of sampling frequency operation speed and other factors. It is also difficult to measure the time difference between P1.0 and P1.1 when low level occurs and ends, so it can only sample P1.0 and P1.1 level quickly. Corresponding to the waveform shown in Fig. 1, the waveform unfolds according to the time axis. Whenever the combined levels of P1.0 and P1.1 are in turn 01 00 10 11 four state codes to form a byte, i.e. 4BH, the left-handed one-bit volume is reduced by 1. When the combined level of P1.0 and P1.1 is 10 000 01 11 four state codes in turn to form a byte, that is, 87H, it means right-handed one-bit volume plus 1. In this paper, "4BH" is called a left-handed one-bit signature, and "87H" is called a right-handed one-bit signature. The task of programming is to recognize these two kinds of characteristic codes in the process of rotating the pulse potentiometer, and to control the volume increment and decrease based on these two codes. In practical programming, two kinds of signatures can be identified in different ways.