ESP32 KY-018 Photoresistor Module

🛠️ KY-018 Photoresistor 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

⚠️ Incorrect or Fluctuating Readings

💻 Code Examples

Below you can find code examples of KY-018 Photoresistor Module with ESP32 in several frameworks:

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

If you encounter issues while using the KY-018 Photoresistor Module, check the Common Issues Troubleshooting Guide.

ESP32 KY-018 Arduino IDE Code Example

Example in Arduino IDE

Fill in your main Arduino IDE sketch file with the following code to use the KY-018 Photoresistor Module:

int sensorPin = A0; // Photoresistor connected to analog pin A0
int sensorValue = 0;

void setup() {
    Serial.begin(9600);
    Serial.println("KY-018 Photoresistor Test");
}

void loop() {
    sensorValue = analogRead(sensorPin);
    Serial.print("Light Intensity: ");
    Serial.println(sensorValue);
    delay(500);
}

This Arduino code sets up the KY-018 photoresistor on analog pin A0. It reads the analog value corresponding to the light intensity and prints it to the serial monitor every 500 milliseconds.

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-018 ESP-IDF Code Example

Example in Espressif IoT Framework (ESP-IDF)

If you're using ESP-IDF to work with the KY-018 Photoresistor 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"

#define PHOTORESISTOR_CHANNEL ADC1_CHANNEL_0 // GPIO36

void app_main(void) {
    adc1_config_width(ADC_WIDTH_BIT_12);
    adc1_config_channel_atten(PHOTORESISTOR_CHANNEL, ADC_ATTEN_DB_0);

    printf("KY-018 Photoresistor Test\n");

    while (1) {
        int raw = adc1_get_raw(PHOTORESISTOR_CHANNEL);
        printf("Light Intensity: %d\n", raw);
        vTaskDelay(pdMS_TO_TICKS(500));
    }
}

This ESP-IDF code configures GPIO36 (ADC1_CHANNEL_0) to read analog values from the KY-018 photoresistor. It prints the raw ADC value, corresponding to light intensity, to the console every 500 milliseconds.

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-018 ESPHome Code Example

Example in ESPHome (Home Assistant)

Fill in this configuration in your ESPHome YAML configuration file (example.yml) to integrate the KY-018 Photoresistor Module

sensor:
  - platform: adc
    pin: GPIO36
    name: "KY-018 Light Intensity"
    update_interval: 500ms
    filters:
      - multiply: 0.00322265625

This ESPHome configuration sets up the KY-018 photoresistor on GPIO36. It reads the analog value every 500 milliseconds and applies a multiplier to convert the raw ADC reading to a voltage value.

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

ESP32 KY-018 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-018 PlatformIO Example Code

Write this code in your PlatformIO project under the src/main.cpp file to use the KY-018 Photoresistor Module:

#include <Arduino.h>

#define PHOTORESISTOR_PIN 36

void setup() {
    Serial.begin(115200);
    Serial.println("KY-018 Photoresistor Test");
}

void loop() {
    int sensorValue = analogRead(PHOTORESISTOR_PIN);
    Serial.print("Light Intensity: ");
    Serial.println(sensorValue);
    delay(500);
}

This PlatformIO code configures GPIO36 as an analog input to read the KY-018 photoresistor sensor values. The light intensity readings are printed to the serial monitor every 500 milliseconds.

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

ESP32 KY-018 MicroPython Code Example

Example in Micro Python Framework

Fill in this script in your MicroPython main.py file (main.py) to integrate the KY-018 Photoresistor Module with your ESP32.

import machine
import time

PHOTORESISTOR_PIN = 36  # ADC input pin
adc = machine.ADC(machine.Pin(PHOTORESISTOR_PIN))
adc.atten(machine.ADC.ATTN_11DB)  # Full range 0-3.3V

while True:
    light_intensity = adc.read()
    print("Light Intensity:", light_intensity)
    time.sleep(0.5)

This MicroPython script configures GPIO36 as an ADC input for the KY-018 photoresistor sensor. The sensor value is read every 500 milliseconds and printed to the console.

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