Digital Humidity and Temperature¶
Measure humidity and temperature
2 variants
| DHT 11 | DHT 22 | |
|---|---|---|
| Temperature Range | 0 - 50C | -40 - 125C |
| Temperature Accuracy | ± 2C | ± 0.5C |
| Humidity Range | 20-80% | 0-100% |
| Humidity Accuracy | ± 5% | ± 2-5% |
| Sampling Rate (readings per second) | 1Hz | 0.5Hz |
| Body Size | 15.5 x 12 x 5.5 mm | 15.1 x 25 x 7.7 mm |
| Operating Voltage | 3-5V | 3-5V |
| Max Current during measurement | 2.5mA | 2.5mA |
Working¶
\[ \text{HH} \ \text{LH} \ \text{HT} \ \text{LT} \ \text{CP} \]
where
- \(HH=\) High Humidity -> Humidity Reading in %
- \(LH=\) Low Humidity
- \(HT=\) High Temperature -> Temperature Reading
- \(LT=\) Low Temperature
- \(CP=\) Checksum Parity
Code¶
#include <DHT.h> // not in-built
DHT dht(pin_name, type_of_sensor);
dht.begin();
dht.readTemperature(); // returns Temperature in C
dht.readTemperature(True); // returns Temperature in F
// returns nan for invalid value
dht.readHumidity() // returns Humidity %
// returns nan for invalid value
#include <DHT.h>
DHT dht(D1, DHT11);
float hum, temp;
void setup() {
dht.begin();
Serial.begin(9600);
}
void loop() {
hum = dht.readHumidity();
temp = dht.readTemperature();
Serial.println(
String(hum) + " " + String(temp)
);
delay(5000);
}
Dependencies¶
- AdaFruit Unified Sensor
- DHT_Sensor
- Time
- TinyGSM
Sensor¶
3 pins
- VCC
- GND
- DOUT/Data/Signal