Sunday, 14 April 2019

identification - How do two-leaded color changing LEDs work?


I have a few 3mm color-changing LEDs which I harvested from a toy. They fade in between all different colors, and then after a little while, they blink crazily between all the colors. After a few moments, the cycle repeats.


What is interesting about them (and what I wasn't expecting) is that they only have two leads, like a normal hobbyist LED.


I understand that, like an RGB LED, they have multiple elements (probably not the right word) inside. But how do they achieve the color changing and cycling?


Here is a picture of the LED in question:


enter image description here


Notice the little bit of black material inside the LED. Could this possibly be a tiny chip?




Answer



I expect they contain a tiny chip (you can see the little black thing inside) which sequences the patterns. It's either a microcontroller or a special purpose IC.


Most likely something like one of these:


They're available in bare die form and connected to the LEDs inside by ultrasonically welded little wires.


LED Flasher chip inside LED


No comments:

Post a Comment

arduino - Can I use TI's cc2541 BLE as micro controller to perform operations/ processing instead of ATmega328P AU to save cost?

I am using arduino pro mini (which contains Atmega328p AU ) along with cc2541(HM-10) to process and transfer data over BLE to smartphone. I...