# Help for big button **URL:** \ **Category:** DIY STUFF\ **Created:** [August 28, 2020, 2:45pm UTC](https://lookmumnocomputer.discourse.group/t/help-for-big-button/1698 "2020-08-28T14:45:35Z")\ **Posts on this page:** 1\ **Showing post:** 36
**Author:** ![fredrik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fredrik/32/682_2.png) [@fredrik](https://lookmumnocomputer.discourse.group/u/fredrik)\ **Post date:** [May 12, 2021, 6:19am UTC](https://lookmumnocomputer.discourse.group/t/help-for-big-button/1698/36 "2021-05-12T06:19:17Z")
> [@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](https://lookmumnocomputer.discourse.group/t/design-glitches-arduino-nano-supply-voltage/795): > > (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 … --- _[View the full topic](https://lookmumnocomputer.discourse.group/t/help-for-big-button/1698)._