This might also be interesting for you: Simple guide on how to use a Hall Sensor with an Arduino

List of components

• Arduino Nano
• Nano Terminal Adapter
• 6 magnets
• Hall sensor KY024
• LED strip
• Jumper cables
• Screws 2x M2 and 1x M3 for the sensor
• Deep groove ball bearing 6807 2RS / 61807 2RS 35x47x7 mm
• 3D printing test setup (STL files in Download section)

Construction of test bench

First we glued the 6 magnets into the 3D printed wheel. Make sure that the magnets are aligned homogeneously. Then the deep groove ball bearing is inserted into the detection wheel. The wheel can now be connected to the 3D printed bracket. Next we attach the Hall sensor KY-024 to the bracket. The Arduino Nano is plugged onto the adapter terminal and also attached to the bracket. The LED strip does not have to be attached separately. So you can start with the wiring.

Wiring

The wiring is not very difficult. Proceed according to the fritzing sketch. Connect the 4 jumper cables to the pins of the Hall sensor KY-024 and connect them to the Arduino Terminal Adapter. The 5V output of the Arduino is shared with both the Hall Sensor and the LEDs. Since there are only a few LEDs, no external power supply is required. For the LED strip you may have to solder them. We recommend to use a 220 Ohm resistor for the digital input of the LED strip.

Arduino Code Simple (with digital input)

In this code example, the Hall sensor KY024 sends the digital value 1 (HIGH) if there is a magnet or 0 (LOW) if no magnet is nearby. As soon as a HIGH is detected, the LEDs start to light up. But if the a magnet stops in front of the Hall sensor, it will send a HIGH constantly and the LEDs won’t stop lightning.

#include <FastLED.h>
#define LED_PIN     7
#define NUM_LEDS    6

CRGB leds[NUM_LEDS];

int digitalPin = 9; // Hall magnetic sensor input 1 (high) or 0 (low)
int digitalInputValue ; // digital readings

void setup ()
{
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
  pinMode (digitalPin, INPUT); 
  
  Serial.begin(9600);
}

void loop ()
{
  
  digitalInputValue = digitalRead(digitalPin) ; 
  Serial.println(digitalInputValue); // print value
  if (digitalInputValue == HIGH) 
  {
    for (int i = 0; i <= 5; i++) 
    {
    leds[i] = CRGB ( 255, 0, 0);
    FastLED.show();
    delay(40);
    }
  }

  else if (digitalInputValue ==LOW)
  {
    for (int i = 0; i <= 5; i++) 
    {
      leds[i] = CRGB ( 0, 0, 0);
      FastLED.show();
      delay(30);
    }
  } 
}

Arduino code more advanced (with analog input)

This code is a bit more advanced. The goal for the Hall Sensor Movement Detection is to let the LEDs light up as soon as a rotary movement is detected. Even if a magnet stops directly in front of the KY024 Hall sensor, the LEDs must not light up, because there is no movement.

For this reason, the analog value of the Hall sensor is considered instead of the digital value. If the analog value changes, a rotary movement takes place. A small offset has been integrated to compensate minor fluctuations that occur even without a rotary movement. A counter was programmed as a double safeguard, which also counts how often the analog value changes. The double protection is intended to prevent the Hall sensor from detecting a magnetic field at a standstill.

#include <FastLED.h>
#define LED_PIN 7
#define NUM_LEDS 6
CRGB leds[NUM_LEDS];


int analogPin =A0;
int analogVal; // analog readings
int detector =0;
int firstVal=0;
int HIGHcount=0;


void setup() {
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);//pinMode (led, OUTPUT); 
  pinMode (analogPin, INPUT); 
  Serial.begin(9600);
  
}

void loop() {
  analogVal= analogRead(analogPin);
  detector = abs(firstVal-analogVal);  //if there is a difference >0 then the wheel might be spinning
  firstVal=analogVal;

  if (detector>4)   //offset = 4 can be adjusted
  {
    HIGHcount++;  //counting the high to eleminate false positives  
    }
  else if (detector<=10)
  {
    HIGHcount=0;
  }

  if (HIGHcount>1)
  {
    YellowToRed(0); 
    delay(1000);
    HIGHcount=0;
    }

  else
  {
     for (int i = 0; i <= 5; i++) 
  {
    leds[i] = CRGB ( 0, 0, 0);
    FastLED.show();
    delay(30);
  } 
    }

}


void YellowToRed(int colorStep)
{
  for( colorStep; colorStep<250; colorStep+=5 ) {

      int r = 255;  // Redness starts at zero and goes up to full
      int b = 0;  // Blue starts at full and goes down to zero
      int g = 255-colorStep;              // No green needed to go from blue to red

      // Now loop though each of the LEDs and set each one to the current color

      for(int x = 0; x < NUM_LEDS; x++){
          leds[x] = CRGB(r,g,b);
          leds[x].maximizeBrightness(255-colorStep);
      }

      // Display the colors we just set on the actual LEDs
      FastLED.show();

      delay(50); 
  }
}

Pictures of the Hall Sensor Movement Detection

Download files

• Magnet Wheel (STL)

The post Hall Sensor Movement Detection appeared first on Nerd Corner.

This might be interesting for you: We built a Hall sensor movement detection wheel

We have already started small Arduino projects. Next we want to build a prayer wheel that will light up when it is rotated. For this we will need a Hall sensor.
This post shows a simple example to explain how to connect a Hall sensor to an Arduino and program it so that an LED starts to light up as soon as the Hall sensor KY024 detects a magnetic field.

List of components

• Arudino Mega
• Jumper cable
• 220 Ohm resistor
• LED
• Magnets
• Hall sensor KY-024

How does a Hall sensor work or what is the Hall effect?

When a current-carrying electrical conductor is in a magnetic field, an electrical field builds up. This is perpendicular to the current direction and to the magnetic field and compensates for the Lorentz force which acts on the electrons.

A Hall sensor also provides a signal when the magnetic field in which it is located is constant. This is the advantage compared to a simple coil, which can only determine the derivation of the magnetic field over time.

The Hall sensor KY-024

The linear magnetic Hall sensor KY-024 can detect magnetic fields and therefore reacts as soon as you approach it with a magnet. It has a potentiometer with which the sensitivity of the sensor can be set. The KY-024 Hall sensor offers both an analog and a digital output.

The digital output acts as a switch that turns on and off when a magnet is nearby. The analog output, on the other hand, can measure the polarity and relative strength of the magnetic field.

KY-024 Arduino Wiring

It is a simple structure that only serves to illustrate the functioning of the KY-024 Hall sensor. Please pay attention to the forward direction of the LED, the kinked end is connected to an Arduino pin and the straight end to GND. Correctly the LED needs a 220 Ohm ballast resistor. However, this can also be neglected for the short duration of use.

Otherwise, connect the GND of the KY-024 to the GND of the Arduino analogous to the Fritzing sketch. Connect the analog output A0 of the KY-024 to A0 of the Arduino Mega. Connect the + of the KY-024 to 5V of the Arduino and connect the digital output D0 of the KY-024 to pin 9 of the Arduino. That was the complete wiring.

Hall sensor KY-024 Arduino Code

int LED = 53 ; // LED
int digitalPin = 9; // Hall magnetic sensor input 1 (high) or 0 (low)
int analogPin = A0; // analog Pin also available, but not necessary
int digitalInputValue ; // digital readings
int analogInputValue; // analog readings

void setup ()
{
  pinMode (LED, OUTPUT); 
  pinMode (digitalPin, INPUT); 
  pinMode(analogPin, INPUT); //not necessary, but it is interesting to see the analog values
  Serial.begin(9600);
}

void loop ()
{
  
  digitalInputValue = digitalRead(digitalPin) ; 
  if (digitalInputValue == HIGH) // When magnet is present, digitalInputValue gets 1 (HIGH) and turns LED on
  {
    digitalWrite (LED, HIGH);
    
  }
  else
  {
    
    digitalWrite (LED, LOW);
  }
  
  //Here you can see the analog values of the sensor
  analogInputValue = analogRead(analogPin);
  Serial.println(analogInputValue); // print analog value

  delay(100);
}

We first define the assignment of the LED (here pin 53), the digital (pin 9) and the analog pin (pin A0) and two variables to read the digital and analog sensor data. The digital pin is sufficient for our purpose of lighting the LED.

The analog pin can actually be neglected. However, since it is useful for this tutorial to show the analog values, the analog pin was nevertheless taken into account in the code.
The respective pin mode is defined in the setup and the digital sensor value of the KY 024 is read in the loop function and, depending on the value, the LED receives the command to light or not. The digital sensor value is either 0 or 1. If you want to, you can use the penultimate 2 lines to display the associated analog values.

Download file

• Hall sensor KY-024 Arduino code

The post How to use the hallsensor KY-024 with Arduino Code and Wiring appeared first on Nerd Corner.