Connect DHT11 and Raspberry Pi without a breadboard

Question

I purchased this temperature and humidity sensor online and I want to use it with my Raspberry Pi 2.

Specs: https://akizukidenshi.com/download/ds/aosong/DHT11.pdf

The tutorials that I find online suggest a wiring scheme that uses a breadboard and a resistor. I do not own a breadboard or a resistor and I do not really intend to buy those for such a small-scale personal experiment.

Is it possible to connect the sensor directly to the GPIO pins? If yes, what are the risks? I do not expect reliability, my goals are to get a few temperature readings while NOT damaging the Pi.

Answer 1

It may work with the internal pull-ups enabled. You'll have to try and see.

Use 3V3 operation so connect DHT11 pin 1 to Pi 3V3 (say pin 1) and DHT11 pin 4 to a Pi ground (say pin 6).

Connect DHT11 pin 2 to any Pi GPIO.

http://abyz.me.uk/rpi/pigpio/examples.html#pdif2_DHTXXD will read the sensor but you'll have to set the pull-up outside the program (or edit the code).

If you connect to GPIO4 (pin 7) you can set the pull-up with the following command.

sudo pigpiod # Start daemon

pigs pud 4 u # set internal pull up

Answer 2

There is no risk if you connect all the pins right. You probably will be fine without the resistor if you activate the internal pullup on the GPIO pin which you connect to pin 2 of the sensor:

GPIO.setup(channel, GPIO.IN, pull_up_down=GPIO.PUD_UP)