You are reading a single comment by @allObjects and its replies.
Click here to read the full conversation.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
@allObjects
I assume, you have plenty of GPIO pins left... choosing a simple RGB LED with common anode on 3.3V and from each cathode a LED forward voltage specific resistor to an Espruino GPIO pin will do. GPIO pin setup with "opendrain" and driven w/ negative logic are a simple and power effective way to drive indicator LEDs. It is called negative logic because writing digital
0 lits LED, where1 turns LED off. The resistors allow you to limit the current nicely and control as well 'equal(ly)' perceived brightness.Red has usually 2.0..2.2 forward voltage, green and blue have 3.2..3.3; therefore, red needs a resistor of higher value than green and blue. Peeking at this site about LEDs will give you some points to start with. There are also other LED calculators out there that help you with sizing the resistors.