A proper way to use a button and an LED

[LarryD]

Using a LED and switch on the same I/O pin, not for the faint of heart:

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Per image #3 in post 331. Made some of these boards a few weeks back. They greatly speed up wiring and in checking out that code with LEDs and switches. Just plug the assembly in the female headers. 6 LEDs and 6 PB switches. Having the PCB on a 18" umbilical cord makes things quite convenient. [2017-07-12_10-56-24.jpg] [2017-07-09_9-48-23.jpg] [2017-07-09_16-01-43.jpg] [bad98a4c15a1385009680f3f89a65278975a8d98.jpg] Edit: See post #392 for the sample sketch to go with this circuit. …

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Got a request for the code that goes with post #334, (Using a LED and switch on the same I/O pin). Forgot to add it to that post so here it is now: /*   Demonstration how to use a pin as an output to a LED   and at the same time, as an input from a switch.   Note:   The LED(s) 'must' be connected to +5V (CA) through a series resistor.   The switch is connected to GND through a 240 ohm resistor.   Typical setup for SMD LEDs:   +5V White  LED - 4.7K - I/O PIN - 240R - Switch - GND   …