I got this single 5050 RGB LED module that I want to connect to BBB:
http://www.ebay.com/itm/1PC-New-RGB-3-Color-Full-Color-LED-SMD-Module-For-Arduino-AVR-PIC-/181259217039?pt=AU_Car_Parts_Accessorieshash=item2a33e4288fvxp=mtr
It says operating voltage: 5v. So if I connect it to BBB's pwm pins,
I would really need to see a datasheet to answer your question. I doubt
very much that 6mA is enough to turn the LEDs on, especially if it likes to
see 5V in its natural environment.
Gerald
On Mon, Jul 28, 2014 at 9:48 AM, Energia dred...@gmail.com wrote:
I got this single 5050 RGB LED
Thanks, Gerald. Well, here it says for this module:
Red Vf: 1.8 to 2.1V
Green Vf: 3.0 to 3.2V
Blue Vf: 3.0 to 3.2V
https://sites.google.com/site/summerfuelrobots/arduino-sensor-tutorials/3-color-rgb-led-module
So in theory I could connect it to BBB's pwm pins (3.3v?) after all but
with 3 x 1k
Well, it won't be bright for sure. Maybe not even on. But as long as the
3.3V is taken from the expansion header it should be OK. As to 1K, that
would be safe.
Gerald
On Mon, Jul 28, 2014 at 10:20 AM, Energia dred...@gmail.com wrote:
Thanks, Gerald. Well, here it says for this module:
Red
no, it will not work connected directly to the BBB as Gerald stated. He
said it will only provide 6mA of current and you have 3 LEDs which, if you
read the specifications, will require more than that for each LED to light.
Voltage is not current but it is related along with resistance via Ohm's
You definitely want to use Ohms Law V=IR
So your input voltage is 5V, and your voltage drop is 1.8-2.1, therefore
you have a net voltage of 3.2 - 2.9 - given that your supply is exactly
5.0V.
What's typical to drive this type of LED is 20ma current source. LEDs are
really current devices not
