Controlling PyQt with GPIO devices

Controlling circuits from Python using GPIO pins is fairly straightforward. It's simply a matter of calling the GPIO.output() function with the appropriate pin number and high or low value. Now, however, we're going to look at the opposite situation, that is, controlling or updating a PyQt GUI from GPIO input.

To demonstrate this, we're going to build a temperature and humidity readout. Just as before, we'll start by connecting the circuit.

Connecting the sensor circuit

The DHT 11 and DHT 22 sensors are both temperature and humidity sensors that can easily work with the Raspberry Pi. Both are packaged as four-pin components, but only three of the pins are actually used...