How to Use KY-005: Examples, Pinouts, and Specs

The KY-005 is a digital temperature and humidity sensor module manufactured by Arduino, with the part ID CINCO. It integrates the DHT11 sensor to provide accurate measurements of temperature and humidity. This module is widely used in environmental monitoring, home automation, weather stations, and other applications requiring reliable climate data.

The KY-005 is compact, easy to use, and compatible with microcontrollers like the Arduino UNO, making it an excellent choice for both beginners and experienced developers.

• Sensor Type: DHT11 (Digital Temperature and Humidity Sensor)
• Operating Voltage: 3.3V to 5.5V
• Temperature Range: 0°C to 50°C (±2°C accuracy)
• Humidity Range: 20% to 90% RH (±5% accuracy)
• Output Signal: Digital (single-bus communication)
• Sampling Rate: 1 Hz (1 reading per second)
• Dimensions: 28mm x 12mm x 10mm

The KY-005 module has three pins, as detailed in the table below:

1. Connect the Pins:

   • Connect the VCC pin to the 5V output of your microcontroller.
   • Connect the GND pin to the ground (GND) of your microcontroller.
   • Connect the DATA pin to a digital input pin on your microcontroller (e.g., pin 2 on an Arduino UNO).

2. Add a Pull-Up Resistor:

   • Place a 10kΩ pull-up resistor between the DATA pin and the VCC pin to ensure stable communication.

3. Upload the Code:

   • Use the Arduino IDE to upload the provided code to your Arduino UNO.

• Ensure the module is not exposed to extreme temperatures or humidity levels beyond its specified range.
• Allow the sensor to stabilize for a few seconds after powering it on before taking readings.
• Avoid placing the sensor in direct sunlight or near heat sources, as this may affect accuracy.
• Use a pull-up resistor to maintain reliable communication between the sensor and the microcontroller.

Below is an example code to read temperature and humidity data from the KY-005 module using the DHT library:

// Include the DHT library for sensor communication
#include <DHT.h>

// Define the pin connected to the DATA pin of the KY-005
#define DHTPIN 2

// Define the sensor type (DHT11)
#define DHTTYPE DHT11

// Initialize the DHT sensor
DHT dht(DHTPIN, DHTTYPE);

void setup() {
  // Start the serial communication for debugging
  Serial.begin(9600);
  Serial.println("KY-005 Temperature and Humidity Sensor Test");

  // Initialize the DHT sensor
  dht.begin();
}

void loop() {
  // Wait a few seconds between measurements
  delay(2000);

  // Read the humidity value
  float humidity = dht.readHumidity();
  // Read the temperature value in Celsius
  float temperature = dht.readTemperature();

  // Check if the readings are valid
  if (isnan(humidity) || isnan(temperature)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

  // Print the results to the Serial Monitor
  Serial.print("Humidity: ");
  Serial.print(humidity);
  Serial.print(" %\t");
  Serial.print("Temperature: ");
  Serial.print(temperature);
  Serial.println(" °C");
}

1. No Data Output:

   • Ensure the DATA pin is connected to the correct digital pin on the microcontroller.
   • Verify that the pull-up resistor (10kΩ) is properly connected between the DATA and VCC pins.

2. Incorrect Readings:

   • Check that the sensor is operating within its specified temperature and humidity range.
   • Avoid placing the sensor in areas with rapid temperature changes or high airflow.

3. "Failed to Read from DHT Sensor" Error:

   • Ensure the DHT library is installed in the Arduino IDE.
   • Verify that the correct pin number and sensor type (DHT11) are defined in the code.

Q: Can the KY-005 be used with a 3.3V microcontroller?
A: Yes, the KY-005 operates within a voltage range of 3.3V to 5.5V, making it compatible with 3.3V microcontrollers.

Q: How often can I take readings from the KY-005?
A: The KY-005 has a sampling rate of 1 Hz, meaning it can provide one reading per second.

Q: Can I extend the cable length of the KY-005?
A: Yes, but keep the cable length as short as possible to avoid signal degradation. If longer cables are necessary, use shielded cables and ensure proper grounding.

Q: Is the KY-005 suitable for outdoor use?
A: The KY-005 is not waterproof and should be protected from direct exposure to rain or extreme environmental conditions. Use a protective enclosure if deploying outdoors.