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Can LED 2 pins be used on port A1-A5?


#1

I have a LED that only have 2 pins, can it be used on port one of those port A1-A5, and control it programmatically?

Thanks!


#2

You can connect the LED to any pin and control it, yes.


#3

Don’t forget a resistor?


#4

If you are using the LED “components” from this website then you can just plug it right in.
If you are connecting an LED directly then yes you need a resistor and the LED must be around 4mA no more.


#5

Ah I see,

I just have a bare LED not a LED component from your store, so I guess I wouldnt be able to connect directly. it sounds complicated…I am not a electrical person :slight_smile:

Thanks!


#6

It is simple but you need to learn about the current limiting resistor


#7

I can connect leds directly without resistors.
To be precise: if I add a resistor, it is very dim.

I always use my leds without resistor and works just fine :wink:


#8

But when something goes wrong , there is no current limiter in the circuit.

It might be blow up your board :frowning:

It is very easy to calculate the resistor you need , so it will be better to use one


#9

True.

Checked out the schematics and you were right. It’s recommended to use a resistor :wink:


#10

If you learn electronics, you will know that if you do not have the resistor then you will simply damage your processor!

You need 220 ohm resistor

The IOs on FEZ are only capable of 4mA. Anything higher and you are risking damaging your FEZ.


#11

Yes Gus, studied electronics, but I guess I was confused of the fact that I thought FEZ had built in resistors and I guess I was too lazy
:stuck_out_tongue:

USE RESISTORS PEOPLE :stuck_out_tongue:


#12

Robert,

It does have built in resisters, but only pullups, not current limiting.


#13

Aaaaaah that’s where my thought went wrong :wink:
Anyway, won’t happen again that I do not use resistors for LED’s :wink:


#14

I learned basic electrical in school 10 years ago, and never apply, so I feel like I dont know a thing when it comes to electrical. I am a handy man and have all soldring equipments and stuffs, so i guess i will google for tips to put together a LED with register. If this is something you guy know on top of your head, without needing to think, I would love to learn how to make one, what parts do i need? a 220 ohms register + a tiny LED and some wires, whatelse?
and how to connect them? :slight_smile:

Thanks!


#15

if you would like to be able to create custom electronics, I would suggest to buy a breadboard (available on this site and almost every hobby electronics store). they are perfect for fast prototyping and you do not need to solder anything :slight_smile:

how to make it work. first, take a wire an connect it to 5v output of fez. (positive) Connect the other side to the resistor (does not matter which side).

next, have a look at the led. it has a longer (anode, positive) and a shorter wire (cathode, negative)

connect the other side of the resistor to the anode (longer pin, positive)

finally, connect a wire to GND (ground, negative) on the fez. connect the other side to the shorter led pin (cathode, negative)

you`re done the led should light up:)
once you got this done you can download the led driver, disconnect the cable at the 5v pin, and connect it to a digital output port to control it by code (take a look at the free book for help)

posted via mobile.


#16

The IOs on FEZ are 3.3V so use 3.3V instead of 5V

Google has answers for all your questions, you just have to ask google!!! :slight_smile:
I asked google and she pointed me to this :wink: http://www.instructables.com/id/LEDs-for-Beginners/


#17

wow,
This is so izi to follow, i feel like I can make LED for living now :slight_smile:

Thank You!


#18

sorry that I did not come up with a scheme before, I was posting via mobile.

Here is a scheme:
http://www.ladyada.net/images/arduino/lesson3sch1.jpg

Here is more detailed information:
http://www.ladyada.net/learn/arduino/lesson3.html


#19

Oh Ok, Thank you!


#20

You’re welcome :wink:
If you run into problems, please let us know :wink: