Design with KY-018 LDR Photo Resistor in Cirkit DesignerThe KY-018 LDR Photo Resistor, manufactured by AZ-Delivery, is a light-dependent resistor (LDR) that changes its resistance based on the intensity of light falling on it. This component is widely used in light sensing applications, such as automatic lighting systems, light meters, and DIY electronics projects. Its simplicity and versatility make it an excellent choice for both beginners and experienced users.
This circuit uses an Arduino UNO to read the light intensity from a KY-018 LDR Photo Resistor. The LDR is powered by the Arduino's 5V and GND pins, and its signal output is connected to the Arduino's analog input pin A0.
Open Project in Cirkit Designer
This circuit connects a KY-018 LDR Photo Resistor to a Raspberry Pi 3B for light sensing applications. The LDR's signal pin is connected to GPIO 11 on the Raspberry Pi, allowing the microcontroller to read the light levels detected by the sensor. The LDR is powered by the Raspberry Pi's 5V and ground pins.
Open Project in Cirkit Designer
This is a light-dependent LED circuit powered by a 9V battery. It uses a 10k Ohm resistor in series with the LED for current limiting, and a photocell (LDR) to adjust the LED brightness based on ambient light levels.
Open Project in Cirkit Designer
This circuit is a light-sensitive relay switch that uses a photocell (LDR) to control a 12V relay via a BC547 transistor. The relay is powered by a 12V battery, and the transistor acts as a switch that is triggered by the resistance change in the LDR, which is influenced by the ambient light level.
Open Project in Cirkit DesignerThe following table outlines the key technical details of the KY-018 LDR Photo Resistor:
| Parameter | Value |
|---|---|
| Manufacturer | AZ-Delivery |
| Part ID | KY-018 |
| Operating Voltage | 3.3V to 5V |
| Resistance Range | ~10 kΩ (bright light) to ~1 MΩ (dark) |
| Maximum Power Rating | 100 mW |
| Response Time | Rise: ~20 ms, Fall: ~30 ms |
| Operating Temperature | -30°C to +70°C |
| Dimensions | 18 mm x 10 mm x 2 mm |
The KY-018 module consists of three pins. The table below describes each pin:
| Pin | Name | Description |
|---|---|---|
| 1 | Signal (S) | Outputs an analog voltage proportional to light intensity. |
| 2 | VCC | Power supply pin (3.3V to 5V). |
| 3 | GND | Ground connection. |
Below is an example of how to connect the KY-018 to an Arduino UNO and read light intensity:
// KY-018 LDR Photo Resistor Example with Arduino UNO
// Reads light intensity and prints the value to the Serial Monitor
const int ldrPin = A0; // KY-018 Signal pin connected to Arduino A0
void setup() {
Serial.begin(9600); // Initialize serial communication at 9600 baud
pinMode(ldrPin, INPUT); // Set the LDR pin as input
}
void loop() {
int lightValue = analogRead(ldrPin); // Read the analog value from the LDR
Serial.print("Light Intensity: ");
Serial.println(lightValue); // Print the light intensity value
delay(500); // Wait for 500ms before the next reading
}
No Output or Incorrect Readings
Output Does Not Change with Light
Fluctuating Readings
Q: Can the KY-018 detect very low light levels?
A: Yes, the KY-018 is sensitive to low light levels, but its response time may increase in darker conditions.
Q: Can I use the KY-018 with a 3.3V microcontroller like the ESP32?
A: Yes, the KY-018 operates within a voltage range of 3.3V to 5V, making it compatible with 3.3V microcontrollers.
Q: How do I calibrate the KY-018 for my application?
A: You can calibrate the module by mapping the analog readings to specific light intensity levels using a reference light source and adjusting your code accordingly.
Q: Is the KY-018 suitable for outdoor use?
A: The KY-018 is not weatherproof. If used outdoors, ensure it is enclosed in a protective casing to prevent damage from moisture and dust.