## LED And Resistor Combinations Quick Reference

I got tired of continuously calculating resistor values for various low-voltage applications (Launchpad, USB power, Batteries, etc), so I put together a Quick Reference Chart. To use: If you want about 20mA through an LED, the LED has a listed Voltage Drop (Forward Bias) of 2.8V, and you have a 4.5V supply (3x AA Batteries), then your appropriate resistor value is 85 Ω