The HC-SR04 ultrasonic distance meter

The HC-SR04 emits an ultrasonic sound wave and measures the time it takes to travel to a target and back. Knowing that sound waves travel at 330m/s the distance between the sensor and the target can be calculated

The cabling is done as described in the following table

TCS3200	!WeMos bus	GPIO
Vcc	5V
TRIG	D2	21
ECHO	D1	22*
GND	GND

* Because the signal emitted by the HC-SR04 has a 5V level and the ESP32 CPU accepts only 3.3V signals, the ECHO signal is passed through a 1kOhms / 2kOhms voltage divider.

-- %USERSIG{UliRaich - 2022-05-30}%

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