RAMPS LEDs

Under construction

Background

Many people want to add in various LEDs to their printers, as lighting or indicators or a bit of "Bling"

LED basics

A standard LED is a two legged electronic device that emits light of a certain color. They have polarity, ie a + (Anode) and a - (Cathode) leg. They will only work when plugged in the correct way. They come in a variety of sizes and shapes and colors. These are current driven devices, what that means practically is that you need to use a resistor in series with the LED to restrict the amount of current that can flow threw the device, or they will take to much current and burn out. They only have two states, on and off. To control the brightness PWM (pulse width modulation) is used to rapidly turn the LED on and and off. RGB leds, these are simply 3 LEDS, one red, one green and one blue in one device. They normally come with four legs. They come in either common cathode or common anode varieties. Ie all the + (anonde) or all the - (cathode) lines are connected together.

LED strips

There are lots of types of LED strips Simple one color strips, these are just a series of surface mount single color leds on a flexible PCB strip. They come in a variety of LED sizes and number of LEDs per meter and colors. They have the current limiting resisters in built. RGB LED strips, are same as the Simple one colour strips but with independent a red,green and blue channels. LED strips with chips. These are normally individually addressable and any LED can be set to any color. These are not directly usable on a ramps, they require very accurate timing which interferes with the normal operation of the machine.