KY-015 Sensor Module : PinOut, Datasheet & Its Working

Maintaining the temperature in Infrastructures is important because it affects the fundamental equipment, particularly servers. If the temperature is not maintained correctly, computers get heated. So unexpected changes in humidity & temperature can meet overheating which may result in larger damages & financial failures. This demonstrates how significant correct cooling is in avoiding sudden downtime. To overcome this issue, temperature and humidity sensors are invented to measure both temperature & humidity and then change these measurements into electrical signals. Thus it can be utilized by other instruments and software. The examples of these sensors are; DHT11, KY-015, SHT10, SHT31, etc. This article elaborates on the KY-015 sensor module, pinout, working, and its applications.

What is the KY-015 Sensor Module?

A KY-015 is a temperature and humidity sensor module or combi-sensor that uses the DHT11 sensor to provide digital output for the temperature & humidity readings. This module can be interfaced directly with microcontrollers like Raspberry Pi, ESP32, Arduino, etc. So it is a convenient method to monitor ecological conditions in a variety of applications like weather stations or home automation. The KY-015 module uses a DHT11 sensor that provides digital format output data. This sensor works with a digital technique that combines exclusive moisture sensing technology to ensure stability & reliability.

How KY-015 Sensor Module Work?

The KY-015 temperature & humidity sensor module works with an internal capacitive humidity sensor & thermistor to measure the nearby surroundings’ humidity and temperature. After that, it transmits digitally like a serial bit sequence throughout a single data pin by allowing a microcontroller to read the values straight without requiring extra ADC conversion.

This module combines both a temperature sensor & a humidity sensor. Different from some other analog sensors, this module provides a digital signal to make it simple to interface with different microcontrollers. The sensor transmits data as a sequence of bits that the microcontroller reads and interprets with a specific library. The KY-015 module draws minimum power to make it appropriate for battery-powered projects.

Pin Configuration:

The KY-015 sensor module pin configuration is shown below. This module includes three pins which are discussed below.

KY-015 Pin Configuration

Pin-1 (Vcc): This pin connects to the 5Volts power supply of your microcontroller board.
Pin-2 (Signal): This is the data pin of the module that sends the temperature & humidity readings from the sensor module to your microcontroller.
Pin-3 (GND): This is a ground pin that is connected to the GND pin of your microcontroller board.

Features & Specifications:

The features and specifications of the KY-015 sensor module include the following.

KY-015 is a humidity and temperature sensor module.
This module uses a DHT11 sensor.
Its operating voltage ranges from 3.3 volts to 5 volts.
Temperature measurement range is from 0°C to 50°C or 32°F to 122°F.
Temperature measurement accuracy is ±2°C.
Humidity measurement range is from 20% to 90% RH
Humidity measurement accuracy is ±5% RH.
The sample rate is 2 seconds approximately.
It is compatible with different platforms like Micro: bit, Raspberry Pi, Arduino, etc.
The signal transmission range is 20m
Humidity measurement error is + / -5%
The temperature measurement range is from 0 – 50°C.
Its temperature measurement error is + / -2°C
The output type is a digital output.
This module uses a red power LED.

Equivalent & Alternatives

Equivalent to the KY-015 sensor module is DHT11. Alternatives to KY-015 sensor module are DHT22, BME280, KY-028, etc.

KY-015 Sensor Module Interfacing with Arduino Uno

KY-015 sensor module interfacing with Arduino Uno is shown below. This sensor module gives a digital serial interface for measuring temperature & environment humidity. It is compatible with different microcontrollers. This module includes a DHT11 digital humidity & temperature sensor, 3 male header pins & a 1 kΩ resistor. This sensor utilizes an internal thermistor & a capacitive humidity sensor to decide the nearby conditions and an internal chip is accountable for changing the readings toward a serial digital signal.

The required components for this interfacing mainly include; the KY-015 sensor module, Arduino Uno, breadboard, and connecting wires. The connections of this interfacing follow as;

KY-015 Sensor Module Interfacing with Arduino UNO

The KY-015 module connects its signal pin to pin 8 of the Arduino board.
Connect the middle pin of the KY-015 module to the +5V of the Arduino board.
The KY-015 module connects its GND pin to the GND pin of the Arduino board.

Code:

The required code for the KY-015 sensor module interfacing with Arduino is shown below.

int DHpin = 8; // input/output pin
byte dat[5];

byte read_data()
{
byte i = 0;
byte result = 0;
for (i = 0; i < 8; i++) {
while (digitalRead(DHpin) == LOW); // wait 50us
delayMicroseconds(30); //The duration of the high level is judged to determine whether the data is ‘0’ or ‘1’
if (digitalRead(DHpin) == HIGH)
result |= (1 << (8 – i)); //High in the former, low in the post
while (digitalRead(DHpin) == HIGH); //Data ‘1’, waiting for the next bit of reception
}
return result;
}
void start_test()
{
digitalWrite(DHpin, LOW);

//Pull down the bus to send the start signal
delay(30);

//The delay is greater than 18 ms so that DHT 11 can detect the start signal
digitalWrite(DHpin, HIGH);
delayMicroseconds(40);

//Wait for DHT11 to respond
pinMode(DHpin, INPUT);
while(digitalRead(DHpin) == HIGH);
delayMicroseconds(80);

//The DHT11 responds by pulling the bus low for 80us;
if(digitalRead(DHpin) == LOW)
delayMicroseconds(80);

//DHT11 pulled up after the bus 80us to start sending data;
for(int i = 0; i < 5; i++)

//Receiving temperature and humidity data, check bits are not considered;
dat[i] = read_data();
pinMode(DHpin, OUTPUT);
digitalWrite(DHpin, HIGH);

//After the completion of a release of data bus, waiting for the host to start the next signal
}
void setup()
{
Serial.begin(9600);
pinMode(DHpin, OUTPUT);
}
void loop()
{
start_test();
Serial.print(“Humdity = “);
Serial.print(dat[0], DEC); //Displays the integer bits of humidity;
Serial.print(‘.’);
Serial.print(dat[1], DEC); //Displays the decimal places of the humidity;
Serial.println(‘%’);
Serial.print(“Temperature = “);
Serial.print(dat[2], DEC); //Displays the integer bits of temperature;
Serial.print(‘.’);
Serial.print(dat[3], DEC); //Displays the decimal places of the temperature;
Serial.println(‘C’);
byte checksum = dat[0] + dat[1] + dat[2] + dat[3];
if (dat[4] != checksum)
Serial.println(“– Checksum Error!”);
else
Serial.println(“– OK”);
delay(1000);
}

Working

The above sketch utilizes the Arduino board’s pin 8 to send & receive data serially from the KY-015. Serial communication can be archived by sending a specific sequence of low or high signals to the sensor & waiting for a reply. Thus humidity & temperature data can be read bit through bit & returned like a group of bytes.

Advantages & Disadvantages

The advantages of the KY-015 sensor module include the following.

It is easily integrated with single-wire serial communication.
These are available in compact size.
It has less power consumption.
They have high accuracy
It has anti-interference capabilities & affordability.
It has a fast response time.
This module is easy to use.
They have good accuracy.
It reduces noise from outside factors to ensure precise readings
These are cost-effective.

The disadvantages of the KY-015 sensor module include the following.

Its sampling rate is slow.
This module provides quite low precision in humidity & temperature measurements than advanced sensors.
It is sensitive to environmental factors.
This sensor module is suitable only for measuring a limited humidity & temperature range.
It outputs a digital signal that needs extra processing to change to analog values if required.
This sensor provides only a new measurement for each couple of seconds, so it is slow for applications requiring frequent updates.
It has fairly low accuracy for both humidity & temperature measurements than more advanced sensors.
It functions only in a humidity & moderate temperature range.
Digital signal transmission can be vulnerable to electrical noise from near components.
It outputs a digital signal that might need extra processing for some applications wherever an analog signal is chosen.

KY-015 Sensor Module Applications

The applications of the KY-015 sensor module include the following.

This module mainly measures both humidity and temperature in different applications.
Home automation systems use this module to adjust HVAC systems automatically based on desired comfort levels.
Weather stations utilize it to record humidity and ambient temperature for weather forecasting.
Growers use this module to optimize plant growth by checking and adjusting humidity and temperature levels.
Data logging incorporates this module to record environmental conditions for analysis.

Please refer to this link for the KY-015 Sensor Module Datasheet.

Thus, this is an overview of the KY-015 sensor module, pin-out, features, specifications, interfacing, and its applications. This module is combined with a temperature & humidity sensor that is used commonly in hobbyist electronics projects. So it measures both ecological temperature & relative humidity with a DHT11 sensor chip. This is an affordable and compact combination of humidity & temperature sensors that supplies digital readings throughout a single data pin. Thus it outputs digital data through a single pin which makes it simple to incorporate with microcontrollers. Here is a question for you, what is the KY-028 module?