ESP32 KY-025 Reed Switch Module

🛠️ KY-025 Reed Switch Module Troubleshooting

This guide outlines a systematic approach to troubleshoot and resolve common problems with the . Start by confirming that the hardware connections are correct, as wiring mistakes are the most frequent cause of issues. If you are sure the connections are correct, follow the below steps to debug common issues.

❌ No Response from Sensor

⚠️ Unstable Analog Readings

💻 Code Examples

Below you can find code examples of KY-025 Reed Switch Module with ESP32 in several frameworks:

• Arduino IDE
• ESP-IDF
• ESPHome
• PlatformIO
• MicroPython

If you encounter issues while using the KY-025 Reed Switch Module, check the Common Issues Troubleshooting Guide.

ESP32 KY-025 Arduino IDE Code Example

Example in Arduino IDE

Fill in your main Arduino IDE sketch file with the following code to use the KY-025 Reed Switch Module:

// Declaration and initialization of the input pins
int analog_input = A0; // Analog output of the sensor
int digital_input = 3; // Digital output of the sensor

void setup() {
    pinMode(analog_input, INPUT);
    pinMode(digital_input, INPUT);
    Serial.begin(9600); // Serial output with 9600 bps
    Serial.println("KY-025 Magnetic field detection");
}

void loop() {
    float analog_value;
    int digital_value;

    // Current values are read out, converted to the voltage value...
    analog_value = analogRead(analog_input) * (5.0 / 1023.0); 
    digital_value = digitalRead(digital_input);

    //... and printed at this point
    Serial.print("Analog voltage value: "); 
    Serial.print(analog_value, 4);
    Serial.print(" V, 	 Threshold value: ");

    if (digital_value == 1) {
        Serial.println("reached");
    } else {
        Serial.println("not reached");
    }
    Serial.println("-------------------------------");
    delay(1000);
}

This Arduino code reads the analog voltage from the KY-025 sensor's analog output and checks the digital output to determine if the magnetic field strength has surpassed the set threshold. The results are printed to the serial monitor every second.

Connect your ESP32 to your computer via a USB cable, Ensure the correct Board and Port are selected under Tools, Click the "Upload" button in the Arduino IDE to compile and upload the code to your ESP32.

ESP32 KY-025 ESP-IDF Code Example

Example in Espressif IoT Framework (ESP-IDF)

If you're using ESP-IDF to work with the KY-025 Reed Switch Module, here's how you can set it up and read data from the sensor. Fill in this code in the main ESP-IDF file:

#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/adc.h"
#include "driver/gpio.h"

#define REED_SENSOR_ANALOG_PIN ADC1_CHANNEL_0 // GPIO36
#define REED_SENSOR_DIGITAL_PIN GPIO_NUM_17

void app_main(void) {
    adc1_config_width(ADC_WIDTH_BIT_12);
    adc1_config_channel_atten(REED_SENSOR_ANALOG_PIN, ADC_ATTEN_DB_11);
    gpio_set_direction(REED_SENSOR_DIGITAL_PIN, GPIO_MODE_INPUT);

    printf("KY-025 Magnetic Field Detection\n");
    while (1) {
        int analog_value = adc1_get_raw(REED_SENSOR_ANALOG_PIN);
        int digital_value = gpio_get_level(REED_SENSOR_DIGITAL_PIN);
        printf("Analog Value: %d, Digital Threshold: %s\n", analog_value, digital_value ? "Reached" : "Not Reached");
        vTaskDelay(pdMS_TO_TICKS(1000));
    }
}

This ESP-IDF code reads the analog value from the KY-025 sensor using ADC on GPIO36 and monitors the digital output on GPIO17 to determine if the magnetic field threshold is exceeded. The results are printed every second.

Update the I2C pins (I2C_MASTER_SDA_IO and I2C_MASTER_SCL_IO) to match your ESP32 hardware setup, Use idf.py build to compile the project, Use idf.py flash to upload the code to your ESP32.

ESP32 KY-025 ESPHome Code Example

Example in ESPHome (Home Assistant)

Fill in this configuration in your ESPHome YAML configuration file (example.yml) to integrate the KY-025 Reed Switch Module

sensor:
  - platform: adc
    pin: GPIO36
    name: "KY-025 Magnetic Field Strength"
    update_interval: 1s
binary_sensor:
  - platform: gpio
    pin:
      number: GPIO17
      mode: INPUT_PULLUP
    name: "KY-025 Magnetic Threshold Trigger"

This ESPHome configuration reads the KY-025 sensor's analog output on GPIO36 and detects the threshold trigger using GPIO17 as a binary sensor. Updates are logged every second.

Upload this code to your ESP32 using the ESPHome dashboard or the esphome run command.

ESP32 KY-025 PlatformIO Code Example

Example in PlatformIO Framework

For PlatformIO, make sure to configure the platformio.ini file with the appropriate environment and libraries, and then proceed with the code.

Configure platformio.ini

First, your platformio.ini should look like below. You might need to include some libraries as shown. Make sure to change the board to your ESP32:

[env:esp32]
platform = espressif32
board = esp32dev
framework = arduino

ESP32 KY-025 PlatformIO Example Code

Write this code in your PlatformIO project under the src/main.cpp file to use the KY-025 Reed Switch Module:

#include <Arduino.h>

#define REED_SENSOR_ANALOG_PIN A0
#define REED_SENSOR_DIGITAL_PIN 17

void setup() {
    pinMode(REED_SENSOR_DIGITAL_PIN, INPUT);
    Serial.begin(115200);
    Serial.println("KY-025 Magnetic Sensor Test");
}

void loop() {
    int analog_value = analogRead(REED_SENSOR_ANALOG_PIN);
    int digital_value = digitalRead(REED_SENSOR_DIGITAL_PIN);
    Serial.printf("Analog: %d, Digital: %s\n", analog_value, digital_value ? "Threshold Reached" : "Not Reached");
    delay(1000);
}

This PlatformIO code reads the KY-025 sensor's analog output and monitors the digital threshold trigger. The values are printed every second.

Upload the code to your ESP32 using the PlatformIO "Upload" button in your IDE or the pio run --target upload command.

ESP32 KY-025 MicroPython Code Example

Example in Micro Python Framework

Fill in this script in your MicroPython main.py file (main.py) to integrate the KY-025 Reed Switch Module with your ESP32.

import machine
import time

REED_SENSOR_ANALOG_PIN = machine.ADC(machine.Pin(36))
REED_SENSOR_ANALOG_PIN.atten(machine.ADC.ATTN_11DB)
REED_SENSOR_DIGITAL_PIN = machine.Pin(17, machine.Pin.IN, machine.Pin.PULL_UP)

while True:
    analog_value = REED_SENSOR_ANALOG_PIN.read()
    digital_value = REED_SENSOR_DIGITAL_PIN.value()
    print("Analog:", analog_value, "Digital:", "Threshold Reached" if digital_value else "Not Reached")
    time.sleep(1)

This MicroPython script reads the KY-025 sensor's analog signal using ADC on GPIO36 and monitors the digital output on GPIO17. The readings are printed every second.

Upload this code to your ESP32 using a MicroPython-compatible IDE, such as Thonny, uPyCraft, or tools like ampy.