KeyeStudio KS0431 | EASY Plug DHT22 Temp & Humidity

KeyeStudio KS0431 EASY Plug DHT22 Temperature and Humidity Sensor

The KeyeStudio KS0431 EASY Plug DHT22 module measures temperature and relative humidity with a calibrated digital sensor. It is useful for Arduino weather stations, smart greenhouse prototypes, indoor climate monitors, and IoT data logging lessons.

Compared with basic DHT11-style modules, DHT22 offers a wider measurement range and better accuracy. The RJ11 EASY Plug connector makes it easier to connect to KeyeStudio boards, while standard Arduino DHT libraries keep firmware simple.

Mount the sensor where air can circulate naturally and away from heat-generating regulators or processors. It pairs well with the OpenELAB UNO R3 Intermediate Kit V2 for environmental sensing projects.

Technical Specifications

Board Layout & Label Guide

• DHT22 sensing body: Expose this area to ambient air for accurate readings.
• RJ11 connector: Connects to the EASY Plug digital port.
• Data line: Single-wire digital sensor data.
• VCC/GND: Power and reference for the module.
• Mounting holes: Fix the module in an enclosure or teaching rig.
• Airflow clearance: Avoid sealed pockets of warm air around the sensor.
• Sampling note: Do not poll faster than the DHT22 recommended interval.

Application Scenarios

1. Temperature and Humidity Monitor

Read DHT22 values and print them to the serial monitor every two seconds.

#include #define DHTPIN 2#define DHTTYPE DHT22DHT dht(DHTPIN, DHTTYPE);void setup() { Serial.begin(115200); dht.begin();}void loop() { float humidity = dht.readHumidity(); float tempC = dht.readTemperature(); if (!isnan(humidity) && !isnan(tempC)) { Serial.print(“temperature_c=”); Serial.print(tempC); Serial.print(” humidity=”); Serial.println(humidity); } delay(2000);}

2. Fan Trigger by Temperature

Switch a fan or relay output when temperature rises above a chosen limit.

#include #define DHTPIN 2#define DHTTYPE DHT22const int FAN_PIN = 8;DHT dht(DHTPIN, DHTTYPE);void setup() { pinMode(FAN_PIN, OUTPUT); dht.begin();}void loop() { float tempC = dht.readTemperature(); if (!isnan(tempC)) { digitalWrite(FAN_PIN, tempC > 28.0 ? HIGH : LOW); } delay(2000);}

3. Comfort Index Logger

Log a simple comfort state based on both temperature and relative humidity.

#include #define DHTPIN 2#define DHTTYPE DHT22DHT dht(DHTPIN, DHTTYPE);void setup() { Serial.begin(115200); dht.begin();}void loop() { float h = dht.readHumidity(); float t = dht.readTemperature(); if (!isnan(h) && !isnan(t)) { bool humid = h > 70.0; bool hot = t > 30.0; Serial.println(humid || hot ? “check ventilation” : “comfortable”); } delay(2000);}

Packing List

• 1 x KeyeStudio EASY Plug DHT22 Temperature and Humidity Sensor

FAQ

Q: Is the output analog?
A: No. DHT22 uses a digital single-wire data protocol.

Q: How often can I read it?
A: Use about a 2-second interval or slower for reliable readings.

Q: Can it be used outdoors?
A: Only with weather protection and airflow; avoid rain and condensation.

Q: Why is temperature high inside my enclosure?
A: Heat from electronics and poor airflow can bias readings.

Q: Does it need calibration?
A: It is factory calibrated, but comparison with a trusted reference is useful for critical projects.

Q: Can it work with 3.3 V boards?
A: Yes, DHT22-class sensors commonly support 3.3 V operation.

Q: Which Arduino library should I use?
A: The common DHT sensor library works for most Arduino examples.

Q: What projects fit this module?
A: Weather stations, greenhouses, HVAC demos, plant monitors, and IoT dashboards.