Lesson 11 Humiture Detection¶
The digital temperature and humidity sensor DHT11 is a composite sensor that contains a calibrated digital signal output of temperature and humidity. The technology of a dedicated digital modules collection and the temperature and humidity sensing technology are applied to ensure that the product has high reliability and excellent long-term stability.
The sensor includes a resistive sense of wet component and an NTC temperature measurement device, and is connected with a high-performance 8-bit microcontroller.
1 * SunFounder Uno board
1 * USB data cable
1 * Humiture sensor module
1 * I2C LCD1602
1 * 3-Pin anti-reverse cable
1 * 4-Pin anti-reverse cable
1 * Dupont wire (F to F)
Only three pins are available for use: VCC, GND, and DATA. The communication process begins with the DATA line sending start signals to DHT11, and DHT11 receives the signals and returns an answer signal. Then the host receives the answer signal and begins to receive 40-bit humiture data (8-bit humidity integer + 8-bit humidity decimal + 8-bit temperature integer + 8-bit temperature decimal + 8-bit checksum).
For more information, please refer to the datasheet of DHT11.
The schematic diagram
Step 1: Build the circuit
Step 2: Open the code file
Step 3: Select correct Board and Port
Step 4: Upload the sketch to the SunFounder Uno board
Now, you can see the value of current humidity and temperature displayed on the LCD.