Ultrasonic Module HC-SR04

***Ultrasonic Module HC-SR04***

รายละเอียด เซนเซอร์ Ultrasonic Module HC-SR04

Module main technical parameters:
1.Working Voltage : 5V(DC)
2.Static current: Less than 2mA.
3.Output signal: Electric frequency signal, high level 5V, low level 0V.
4.Sensor angle: Not more than 15 degrees.
5.Detection distance: 2cm-450cm.
6.High precision: Up to 0.3cm
7.Input trigger signal: 10us TTL impulse
8.Echo signal : output TTL PWL signal
Mode of connection:
1.VCC
2.trig(T)
3.echo(R)
4.GND
Use method:
Supply module with 5V, the output will be 5V while obstacle in range, or 0V if not.The out pin
of this module is used as a switching output when anti-theft module, and without the feet when
ranging modules.
Note : the module should be inserted in the circuit before been power, which avoid producing
high level of misoperation;if not, then power again.
Module Working Principle:
1.Adopt IO trigger through supplying at least 10us sequence of high level signal.
2.The module automatically send eight 40khz square wave and automatically detect whether receive
the returning pulse signal.
3.If there is signals returning, through outputting high level and the time of high level
continuing is the time of that from the ultrasonic transmitting to receiving. Test distance =
(high level time * sound velocity (340M/S) / 2.

Note : This module is not suitable to connect with electric power, if you need to connect this
module with electronic power,then let the GND terminal of this module to be connected
first,otherwise, it will affect the normal work of the module

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1. /*
2. * Ultrasonic Sensor HC-SR04 and Tutorial
3. *
4. * by Dejan Nedelkovski,
5. * www.HowToMechatronics.com
6. *
7. */
9. // defines pins numbers
10. const int trigPin = 9;
11. const int echoPin = 10;
13. // defines variables
14. long duration;
15. int distance;
17. void setup() {
18. pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
19. pinMode(echoPin, INPUT); // Sets the echoPin as an Input
20. Serial.begin(9600); // Starts the serial communication
21. }
23. void loop() {
24. // Clears the trigPin
25. digitalWrite(trigPin, LOW);
26. delayMicroseconds(2);
28. // Sets the trigPin on HIGH state for 10 micro seconds
29. digitalWrite(trigPin, HIGH);
30. delayMicroseconds(10);
31. digitalWrite(trigPin, LOW);
33. // Reads the echoPin, returns the sound wave travel time in microseconds
34. duration = pulseIn(echoPin, HIGH);
36. // Calculating the distance
37. distance= duration*0.034/2;
39. // Prints the distance on the Serial Monitor
40. Serial.print("Distance: ");
41. Serial.println(distance);
42. }