How Test Reed Switch in Arduino |The Ultimate Beginner’s Guide

A reed switch detects the presence of a magnet. A cylindrical glass tube that detects the current magnet field from a magnet is the main feature of a reed switch. In this guide, I show you how you will use the Arduino to test a reed switch.

Parts List

if you want to complete How Test Reed Switch in Arduino Tutorial, you have to need the following component

1. Arduino uno — — — amazon/ banggood/ aliexpress
2. Reed switch Module — — — amazon/ banggood/ aliexpress
3. Breadboard — — — amazon/ banggood/ aliexpress
4. Connecting Wires —amazon/ banggood/ aliexpress

Schematic Diagram

Arduino with Reed Switch

Arduino — — — - Reed switch Connection

3.3-V — — — — -VCC

GND — — — — GND

Digital pin 7 — — — D0 pin

Program Arduino with Reed Switch Test

int ReedSwitchPin = 7;
int RawValue = 0;

void setup()
{
pinMode(ReedSwitchPin, INPUT);
Serial.begin(9600);
Serial.println(“Reed Switch Test ….”);
}

void loop()
{
RawValue = digitalRead(ReedSwitchPin);
if (RawValue == 0)
{
Serial.print(“Reed Switch Detects Magnet … “);
}
else
{
Serial.print(“No Magnet Detected …”);
}

// 1 is off, 0 is activated by magnet
Serial.print(“ , RawValue: “);
Serial.println(RawValue);
}

Upload your Arduino program and start the Serial Monitor. The output shows the magnetic field detection status and the associated raw value read from the reed switch. Take a magnet and put it near the reed switch. You should see the messages being printed to the Serial Monitor to indicate a magnetic field has been detected.

Program Analysis

int ReedSwitchPin = 7;
Assigning the D0 pin on the reed switch to the Arduino digital pin 7 to output the state of the magnetic field detection.

int RawValue = 0;
Initialization of RawValue, which holds the read value from the reed to 0.

void setup()
Defining the setup() function, which:

pinMode(ReedSwitchPin, INPUT);
Sets the mode of the pin that reads in data from the reed switch to INPUT.

Serial.begin(9600);
Serial.println(“Reed Switch Test ….”);
Starts the Serial Monitor and prints a message that the program is running.

void loop()
Defining the loop() function, which:

RawValue = digitalRead(ReedSwitchPin);
Reads the value from the reed switch.

if (RawValue == 0)
If this value is 0, then the reed switch has detected a magnetic field.

Serial.print(“Reed Switch Detects Magnet … “);
If this value is 1, then the reed switch has not detected a magnetic field.

Serial.print(“No Magnet Detected …”);

Serial.print(“ , RawValue: “);
Serial.println(RawValue);
Print out the status of the magnetic field and the raw value read from the reed switch to the Serial Monitor.

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