The SunFounder HC-SR04 Ultrasonic Ranging module includes an ultrasonic transmitter, receiver and circuits. It has 4 pins: VCC, TRIG, ECHO and GND. The anti-reverse pin header onside makes it easy to connect and apply.
As for the ranging principle, it is quite simple to understand: pull up the pin Trig to High thus providing high level signals of at least 10us, so the module starts to detect and measure the distance; if an object is detected, the ECHO pin will be High, and the duration of it being High depends on the distance detected, thus giving the distance calculation formula: Distance = Duration of High ECHO * Speed of sound (340m/s)/2.
For more details, visit http://wiki.sunfounder.cc/index.php?title=Ultrasonic_Module
Operating voltage: 5V
Working current: 16mA.
Dimensions: 46 x 20.5 x 19.5 mm (thickness of anti-reverse pin socket included)
5 HC-SR04 Ultrasonic Sensors
10 Female-Male Dupont Cables
10 Female-Female Dupont Cables
1 Exquisite package box
Increased ranging distance to 7m, providing stable signal within 5m, and gradually faded signal outside 5m till disappearing at 7m position.
Uses IO trigger for ranging, generating high level signal of at least 10us.
Operating voltage: 5V; Working current: 16mA.
Equipped with anti-reverse pin socket – making the wiring much tighter and convenient; 4-pin anti-reverse cable also included.
Uses the MCU STC15W104 which has a built-in clock, no need of external crystal oscillator.