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How can RPI GPIO read the 12V output signal?
Wire 3.3Vdc from your Pi to one side of the contact and the other to a GPIO input. Ensure you use a pull down resistor with the relay contact and a current limiting resistor directly in front of the GPIO point. The 12Vdc will be wired to the relay coil.
What kind of relay do you need for GPIO?
You need to use an interposing relay. This is simply a mechanical or solid state relay that has a 12Vdc coil and at least one contact (typically a form C contact, aka single pole double throw). Wire 3.3Vdc from your Pi to one side of the contact and the other to a GPIO input.
How to enable pull up and pull down in GPIO?
You enable these internal pull-ups/pull-downs at the time of setting up the port for input or output, by adding an extra, optional, argument to the GPIO.setup () function call. We’re using pull-down, so it’s pull_up_down=GPIO.PUD_DOWN. If you want/need pull-up you can change the PUD_DOWN for PUD_UP.
What can a GPIO port be used for?
Any wires attached to the GPIO ports act as antennae for this radiation (it’s mostly radio waves). So imagine the situation where you have a motor with a propellor on it, or one which controls Granny’s stairlift, which is controlled by a GPIO input port.
Can you combine inputs and outputs in GPIO?
T oday, it’s time for us to combine inputs and outputs into the same script. It’s nothing scary and it’s not new either. It’s simply a case of doing what we’ve already done in the last two days’ of GPIO basics, but combining them.
Which is the output of RPi.gpio in BCM mode?
You can use GPIO.HIGH or GPIO.LOW and True or False as well, but I prefer 1 or 0 because it’s less keystrokes. Let’s have a working example. We’ll set up RPi.GPIO in BCM mode, set GPIO24 as an output, and switch it on and off every half second until we CTRL+C exit.
What kind of power does a Raspberry Pi GPIO use?
All the GPIO ports take their power from the Raspberry Pi’s 3.3V (3V3) supply. The maximum recommended current draw from that supply is 51 mA. This is the total for all the 3V3 GPIO pins. This is more than enough for controlling logic gates and integrated circuits.