Relationship Between The Motor Output Angle And Input Pulse; Ultrasonic Working Sequence - Keywish Hummer-Bot Instruction Manual

Fig.3.2.27 Relationship between the Motor Output Angle and Input Pulse
2. The ultrasonic
The most commonly used method of ultrasonic distance measurement is echo detection method, the
ultrasonic transmitter launches ultrasonic toward a direction and starting the time counter at the same time,
the ultrasonic will reflect back immediately when encountering a blocking obstacle, and stopping the
counter immediately as soon as the reflected ultrasonic is received by the receiver. The working sequence
diagram is shown in Fig.3.2.28. The velocity of the ultrasonic in the air is 340m/s, we can calculate the
distance between the transmitting position and the blocking obstacle according to the time t recorded by the
time counters, that is: s=340*t/2.
Let us analyze the working sequence, first the trigger signal starts the HC-RS04 distance measurement
module, which means the MCU sends an at least 10us high level to trigger the HC-RS04,the signal sent
inside of the module is responded automatically by the module, so we do not have to manage it, the output
signal is what we need to pay attention to. The output high level of the signal is the transmitting and
Fig.3.2.28 the Ultrasonic Working Sequence
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