Arduino projects, sensors and actuators

Moving average on analog input

Description

This small project shows how to implement a moving average with a lightweight form in order to smooth raw analog values.

The value is then used to position a servo

Image

code Arduino:

	/*
	AnalogReadSerial
	Reads an analog input on pin 0, prints the result to the Serial Monitor.
	Graphical representation is available using Serial Plotter (Tools > Serial Plotter menu).
	(Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.)
	creates a moving average of the analog value read
	positions the servo according to the averaged value read
	*/
	#include <Servo.h>
	Servo myservo; // create servo object to control a servo
	int val; // variable to send servo position
	int k = 32;
	int analog_av = 0;
	int analog_hist[32];
	int i = 0;
	// the setup routine runs once when you press reset:
	void setup() {
	// initialize serial communication at 9600 bits per second:
	Serial.begin(9600);
	myservo.attach(9); // attaches the servo on pin 9 to the servo object
	val = 0;
	for (int n = 0; n < k; n++) {
	analog_hist[n] = 0;
	}
	analog_av = 0;
	}
	// the loop routine runs over and over again forever:
	void loop() {
	// read the input on analog pin 0:
	int sensorValue = analogRead(A0);
	//compute mobile average
	int sensor_divided = sensorValue / k;
	analog_av = analog_av + sensor_divided - analog_hist[i];
	analog_hist[i] = sensor_divided;
	i ++;
	if (i == k) {
	i = 0;
	}
	delay(100); // delay in between reads for stability
	// print out the value you read:
	char disp;
	disp = sensorValue + " / " + analog_av;
	//drive servo
	val = map(analog_av, 600, 700, 140, 0);
	val = max(0, val);
	val = min(140, val);
	myservo.write(val);// sets the servo position according to the scaled value
	delay(25); // waits for the servo to get there
	Serial.println(val);
	}

view raw Arduino-AnalogToServo.ino hosted with ❤ by GitHub

Using Ultrasonic sensor 

Description

In this project, we are using a US sensor. Very first step to understand the behaviour of the sensor through the serial interface.

Image

code Arduino:

	/*
	* Ultrasonic Sensor HC-SR04 and Arduino*
	*/
	// defines pins numbers
	const int trigPin = 9;
	const int echoPin = 10;
	// defines variables
	long duration;
	int distance;
	void setup() {
	pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
	pinMode(echoPin, INPUT); // Sets the echoPin as an Input
	Serial.begin(9600); // Starts the serial communication
	}
	void loop() {
	// Clears the trigPin
	digitalWrite(trigPin, LOW);
	delayMicroseconds(2);
	// Sets the trigPin on HIGH state for 10 micro seconds
	digitalWrite(trigPin, HIGH);
	delayMicroseconds(10);
	digitalWrite(trigPin, LOW);
	// Reads the echoPin, returns the sound wave travel time in microseconds
	duration = pulseIn(echoPin, HIGH,50000);
	// Calculating the distance
	distance= duration*0.034/2;
	// Prints the distance on the Serial Monitor
	Serial.print("Distance: ");
	Serial.println(distance);
	}

view raw Arduino-USSensor.ino hosted with ❤ by GitHub