Resistors

A common question that comes up about pull-up resistors: what value do you pick and why not just use a piece of wire? In this follow-up electronics tutorial, the bald engineer looks at how to pick pull-up resistor values. Show Notes Pull-Up Resistor Tutorial (Episode 15) AddOhms Discord Server Arduino Internal Pull-Up Resistor Tutorial (baldengineer.com) Chuck Norris On Pull-Up Resistors (baldengineer.com)

There is nothing more frustrating than a push button that seems to work at random. The good news is the fix is pretty simple: a resistor. It may not seem obvious when you first start working with electronics but a “floating pin” doesn’t have a defined “high” or “low” level. Remember from the Analog and Digital video, that Digital Electronics has defined voltage levels. Well, when you don’t connect anything to the I/O pin of your microcontroller, the voltage level is undefined!

https://youtu.be/EQtwsWJuUPs Understanding voltage dividers means understanding Ohm’s Law. A common use for a voltage divider in most projects is to monitor a battery. Say you are powering your circuit with a 9V or 12V battery. Microcontroller boards don’t do well with those voltages. In a future video, we’ll come back and look at more circuits that can use voltage dividers. Episode Notes Correction: There is a mistake around 3:00. I say “91 millivolts” and I should have said “910 millivolts!”