Shield DHT22

In this project we will turn on a fan when it reaches a high temperature and turn it off when it is at room temperature. For this project we will use the DHT22, a temperature and humidity sensor, for which we will create a PCB of an ARDUINO UNO SHIELD for the respective tests.

GERBER PCB

https://mega.nz/file/7Jw1VTiY#3TEJ26Sf8TsLg5ly3zVNjOk_-EWkYro8t2pTbdZqdcs

DHT22:

The DHT22 (AM2302) is a high performance, low cost digital temperature and relative humidity sensor. It integrates a capacitive humidity sensor and a thermistor to measure the surrounding air, and displays the data through a digital signal on the data pin (no analog output). Used in applications of automatic temperature control, air conditioning, environmental monitoring in agriculture and more.

Using the DHT22 sensor with the ARDUINO/RASPBERRY PI/NODEMCU platforms is very simple both at the software and hardware level. At the software level there are libraries for ARDUINO with support for the "Single bus" protocol. As for the hardware, it is only necessary to connect the VCC power pin to 3-5V, the GND pin to Ground (0V) and the data pin to a digital pin on our ARDUINO. If you want to connect several DHT22 sensors to the same ARDUINO, each sensor must have its own data pin. Perhaps the only disadvantage of the sensor is that new data can only be obtained every 2 seconds. Each sensor is factory calibrated to obtain calibration coefficients recorded in its OTP memory, ensuring high stability and reliability over time. The communication protocol between the sensor and the microcontroller uses a single wire or cable, the maximum recommended cable length is 20m, preferably using shielded cable. Protect the sensor from direct sunlight (UV radiation).

El DHT22 presenta mejores prestaciones respecto al sensor DHT11, como mejor resolución, mayor precisión y un empaque más robusto.

TECHNICAL SPECIFICATIONS

· Operating Voltage: 3V - 6V DC

· Temperature measurement range: -40°C to 80°C

· Temperature measurement accuracy: <±0.5 °C

· Resolution Temperature: 0.1°C

· Humidity measurement range: 0 to 100% RH

· Humidity measurement accuracy: 2% RH

· Humidity Resolution: 0.1%RH

· Sensing time: 2s

· Digital interface: Single-bus (bidirectional)

· Model: AM2302

· Dimensions: 20*15*8mm

· Weight: 3 grams.

· White plastic shell

PINS

1. Supply: +5V (VCC)

2. Data (DATA)

3. Not Used (NC)

4. Ground (GND)

*We recommend using a 4.7K Ohm pull-up resistor between the Data pin and VCC

ELECTRONIC COMPONENTS:

· 1 DHT22

· 1 RESISTOR 4.7K 1/4W

· 3 RESISTORS 220 ohm 1/4W

· 1 RESISTOR 100 ohm 1/4W

· 1 RESISTOR 1K 1/4W

· 1 TRANSISTOR 2N2222A

· 2 DIODES 1N4148

· 3 DIODES LES 3MM

· 1 RELAY 5VDC

· 1 BLADE (40 PINS)

· 1 2-PIN TERMINAL BLOCK

· 1PCB

FEATURES:

· VIN 5V

· 3 DIGITAL OUTPUTS

· 3 OPERATING RANGES (20-30-40) C°

· IMAX 100mA

We thank JLCPCB for professional PCBs

Order your PCBs here

https://jlcpcb.com/RAV

5PCBS AT $2

GERBER PCB:

https://mega.nz/file/7Jw1VTiY#3TEJ26Sf8TsLg5ly3zVNjOk_-EWkYro8t2pTbdZqdcs