Written: 11 June 2015
Last Updated: 25 June 2015
- Click the Table of Contents link above --> then look under the "Arduino" heading
- Quick Tip: A Comprehensive List of Helpful Arduino Learning Links - New!
- Arduino Power, Current, and Voltage Limitations
- The Power of Arduino
- Using the Arduino Uno’s built-in 10-bit to 21-bit ADC (Analog to Digital Converter)
- eRCaGuy_ButtonReader Library for Arduino - Debounce and read the current button state, & most recent action ("just pressed" or "just released") easily!
- Arduino micros() function with 0.5us precision - using my Timer2_Counter Library
- Quick Tip: 4 Ways to Power an Arduino
- Recommended Soldering Kit & Tutorials (for Arduino, Electronics, & Radio Control)
- A Few Tips & Tricks: Arduinos, PCB Tricopter Frames, Home-made Acid Etchant for Copper
If you've read my article titled "Arduino Power, Current, and Voltage Limitations" you know that the maximum input voltage for any pin input/output pin is Vcc + 0.5V, or +5.5V for a 5V Arduino. The minimum acceptable input voltage is -0.5V. However, if you simply add a single resistor in series with any input pin, you can protect it against higher or lower input voltages!
Ex: simply by placing a 10k resistor in series on an input pin, you get input voltage protection up to +15.5V and down to -10.5V. With a 100k resistor you get input voltage protection up to +105.5V, and down to -100.5V. Keep reading to learn more.