Here is a simple Arduino Camping Light project. In this design, only one push button switch is used to control the light output (from a bunch of white LEDs) between off, dim, medium, and full ...

To read each button push ... columns gets a pull-down resistor. We used 1Kohm resistors for R11, R12, R13, and R14; one lead connects to the columns and the other is grounded. Arduino pins ...

PIC, AVR, and Arduino are ubiquitous in projects these ... Three resistors and a capacitor later he’s in business, adding another resistor and a transistor to deal with the load switching.