Arduino Nano - Ultrasonic Sensor - LED
This tutorial instructs you how to use Arduino Nano and ultrasonic sensor to control LED. In detail:
- Arduino Nano turns on the LED if the object is near the ultrasonic sensor.
- Arduino Nano turns off the LED if the object is distant from the ultrasonic sensor.
Hardware Preparation
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
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Overview of LED and Ultrasonic Sensor
If you are unfamiliar with LED and ultrasonic sensor, including pinout, how they work, and how to program them, the following tutorials can help:
Wiring Diagram
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Arduino Nano Code
/*
* This Arduino Nano code was developed by newbiely.com
*
* This Arduino Nano code is made available for public use without any restriction
*
* For comprehensive instructions and wiring diagrams, please visit:
* https://newbiely.com/tutorials/arduino-nano/arduino-nano-ultrasonic-sensor-led
*/
#define TRIG_PIN 3 // The Arduino Nano pin connected to TRIG pin of ultrasonic sensor
#define ECHO_PIN 2 // The Arduino Nano pin connected to ECHO pin of ultrasonic sensor
#define LED_PIN 10 // The Arduino Nano pin connected to LED
#define DISTANCE_THRESHOLD 50 // in centimeters
float duration_us, distance_cm;
void setup() {
Serial.begin (9600); // Initialize the Serial to communicate with the Serial Monitor.
pinMode(TRIG_PIN, OUTPUT); // set arduino pin to output mode
pinMode(ECHO_PIN, INPUT); // set arduino pin to input mode
pinMode(LED_PIN, OUTPUT); // set arduino pin to output mode
}
void loop() {
// Produce a 10-microsecond pulse to the TRIG pin.
digitalWrite(TRIG_PIN, HIGH);
delayMicroseconds(10);
digitalWrite(TRIG_PIN, LOW);
// Measure the pulse duration from the ECHO pin
duration_us = pulseIn(ECHO_PIN, HIGH);
// calculate the distance
distance_cm = 0.017 * duration_us;
if (distance_cm < DISTANCE_THRESHOLD)
digitalWrite(LED_PIN, HIGH); // turn on LED
else
digitalWrite(LED_PIN, LOW); // turn off LED
// print the value to Serial Monitor
Serial.print("distance: ");
Serial.print(distance_cm);
Serial.println(" cm");
delay(500);
}
Detailed Instructions
- Plug the USB cable into the Arduino Nano and PC.
- Launch the Arduino IDE and select the appropriate board and port.
- Copy the code and open it in the Arduino IDE.
- Click the Upload button on the Arduino IDE to compile and upload the code to the Arduino Nano.
- Move your hand in the vicinity of the sensor,
- Check out the alteration in the LED's state.
Code Explanation
Check out the line-by-line explanation contained in the comments of the source code!
※ NOTE THAT:
The code above is for educational purposes. The ultrasonic sensor is very sensitive to noise. If you want to use it in a practical setting, you should filter out the noise for the ultrasonic sensor. For more information on how to do this, please refer to how to filter noise for ultrasonic sensor.