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ultrasound at 40 kHz and raise its echo. The echo is a distance object that is pulse width and
the range in proportion .You can calculate the range through the time interval between
sending trigger signal and receiving echo signal. Thus,
uS / 58 = centimeters or uS / 148 =inch; or: the range = high level time * velocity (340M/S) / 2
;
You're recommended to use over 60ms measurement cycle, in order to prevent conflicts
between trigger signal and echo signal.
Line Follower Module
The TCRT5000 infrared photoelectric switch adopts a high transmit power infrared
photodiode and a highly sensitive phototransistor. It works by applying the principle of
objects' reflecting IR light – the light is emitted, then reflected, and sensed by the synchronous
circuit. Then it determines whether there exists an object or not by the light intensity. It can
be used to easily identify black and white lines.
In other words, the different conduction levels of the phototransistor when it passes over
black and white lines can generate different output voltages. Therefore, all we need to do
is to collect data by the AD converter on the STM8S105C4 and then send the data to the
master control board via I2C communication.
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