Powering 12V keypad through Arduino Uno Arduino Uno

I'm currently working on a project which will involve entering a sequence on a 12V keypad. The keypad and its documentation can be found here: https://www.jaycar.com.au/digital-keypad-with-rfid-access-control/p/LA5353



They keypad wants 9-18V AC/12~24V DC. I'll be using the keypad to output 26 bit Wiegand to the Arduino. I'm just wondering the best way to power this system. The schematics included with the keypad show that the keypad and the controller  (Arduino) should be sharing a power source. See image attached.

How can I power the 12-24V keypad through the arduino without frying it?
How can I power the 12-24V keypad through the arduino without frying it?


If you power the Arduino with slightly more than 12V (through the barrel jack) then you can get 12V (or slightly less than you power the Arduino with) from the VIN pin.

However the Arduino's on-board voltage regulator does tend to get a little hot when such a high voltage is used to power it. Better is just to power the keypad separately from the correct power source.

And don't forget to connect the grounds together.