Help for big button

[fredrik]

@analogoutput

So the digital pins should be about 5 V when on.

The stripboard layout has the 78L05 connected to VIN, so the internal supply rail would be ~3.8 V for a regular Nano. Which is 10× the reported value…

Design glitches: Arduino Nano supply voltage

(thought I’d collect my nano supply notes in one place to make it easier to link to) A common design glitch in circuits that use an Arduino Nano is to connect regulated 5 V to the VIN pin instead of the +5V pin. This results in the Arduino running at a lower internal supply voltage, often 4 V or below, which may be a problem if the design depends on analog inputs or digital output levels. Voltages below 4.5 V are also out of spec for the 16 MHz clock used by the Nano. Details below, but TL;DR …