Waveshare AlphaBot, User Manual

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AlphaBot User Manual
16
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Speed testing module
The speed testing module
contains a coded disc and a
WYC-H206 photoelectric sensor.
WYC-H206 photoelectric sensor
has an infrared transmitter and
an infrared receiver. When the
infrared receiver is
obscured
,
unable to receive infrared light,
the sensor will output a high level voltage. The high level voltage passes the
inverting schmitt trigger and becomes a low level voltage. At this point, the relative
indicator lights up. When the coded disc runs, DOUT will output a series of high
level pulses and low level pulses. By checking the number of the pluses in a cycle
time, you can get the speed of the smart robot. Here, we use the schmitt trigger
because it has a stable output signal, a clear waveform without any jitter.