Item Description:

Item Features
HC-SR04 ultrasonic module can offer non-contact distance sensing function， the range of which is 2cm—400cm.， and the range accuracy is up to 2mm; the module includes ultrasonic transmitter， receiver and control circuit.

Working Voltage : 5VDC
Static current: Less than 2mA.
Output signal: Electric frequency signal， high level 5V， low level 0V.
Sensor angle: Not more than 15 degrees.
Detection distance: 2cm-500cm.
High precision: Up to 0.3cm
Input trigger signal: 10us TTL impulse
For Echo signal : output TTL PWM signal

The basic operation principle is below:
(1)use IO port TRIG to trigger ranging. It needs 10 us high level signal at least
(2)Module can send 8 pro 40 kz square wave automatically， and will test if there is any signal returned.
(3)If there is signal returned， output one high level signal via IO port for ECHO. The duration of the high level signal is the time from transmitter to receiving with the ultrasonic.
Testing distance =duration of high level*voice velocity(340m/s) / 2

Note:
1. for this module， keep in mind not to connect with electricity. If it is connected with electricity， you need to connect up the GND port of the module firstly， otherwise it will affect the normal working of the module.
2. When testing， the coverage of the tested object is 0.5 square meter or below， and try to make the plate smoothly.， otherwise， it will affect the result of the testing.

Package Included
1x Distance sensor

Item Pictures: