Asked
— Edited
the signal ports on the ez-b4 ,does that give volt?.when i see the tutorial from the leds,
i see they are connected to gnd and to signal ports. *blush*
the signal ports on the ez-b4 ,does that give volt?.when i see the tutorial from the leds,
i see they are connected to gnd and to signal ports. *blush*
leds
Sidenote though : I have used 5mm leds on the digital output with no problem but different components have different voltage compatibility range. His apparently are more sensitive. There are some leds meant for 1.5 to 2v range and those can pop if they get too much voltage.
The V3 outputs +5v on the signal pins. So, if for instance your LED has a forward voltage of +3.0v and a forward current of 20mA you would require a 100ohm 1/8w resistor.
To make calculations for a single LED easier there are many online calculators out there, including this one.
This post was on 3/27/2013. This post explains why you do not need a resistor. Thanks
"LEDs
LEDs come in all sorts of colors. The clear Blue, Red, Green and White LEDs make your project look great. You can connect an LED directly to the Digital Pin of your EZ-B. The Peripheral Extension cables make it very easy also!
The diagram below shows how to connect an LED to an EZ-B digital pin. The light can be controlled by using a Digital Control in ARC, or an EZ-Script command Set(). The one thing to notice is an LED connected to a digital port on the EZ-B does not need a resistor. This is because the digital ports on the EZ-B have pull-up resistors built-in."
5V LEDS
@Purple, by all means run your LEDs without resistor however I will always advise to correctly calculate the resistor for driving LEDs which have forward voltage of less than +5V.
The reason I always advise a resistor is purely and simply because I have burnt up some LEDs which were powered via the signal pin of the EZ-B V3. Nothing says more about requiring a resistor than a burnt out LED in my opinion. On the flip side, I have also run LEDs from the signal pin without issue. To save burning out any more LEDs I have since used and advised the use of a resistor, the cost of the resistor is next to nothing (literally, it's less than 1p for a resistor!).
5 volt leds are great good link.