How to realize temperature and humidity Sensor DHT11 by Raspberry Pie

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1. Connect the line

I bought this DHT11 is rather depressed, three pins, did not indicate which is VCC, which is GND, searched a bunch on the Internet, marked for other sensors are clearly marked, mine only marked a plus or minus sign, and then consulted with a treasure boss, confirmed that it is + is VCC,- is GND, the middle is Data (maybe because I am a rookie in telecommunications, do not understand these jargon)

1-> 3.3v connect the first GPIO pin on the left

2-> GPIO data interface, you can connect one GPIO pin at will (the seventh pin corresponds to GPIO Pin # 4, corresponding to the following code)

3-> GND ground (6th pin or other GND)

2. Install the gpio driver (let's call it the driver, the principle is not clear)

Sudo apt-get install wiringpi

3. Run the example (C code)

# include # define MAX_TIME 100#define DHT11PIN 7 / / read data pin # define ATTEMPTS 5 / / retry 5 times when no responseint dht11_val [5] = {0meme0 0re0re0}; int dht11_read_val () {uint8_t lststate=HIGH; / / last state uint8_t counter=0; uint8_t jigsaw 0PowerI; for