Author Topic: LED's on the Roboduino. (Read 2566 times)

offy · « **on:** March 13, 2009, 07:46:03 PM »

I want to hook up 2-4 LED's (blue) to my roboduino. I don't know where I would connect them to or how. the LED's have 2connectors, no HiTec connector on them. I would not like to solder.

SmAsH · « **Reply #1 on:** March 13, 2009, 07:47:54 PM »

http://www.societyofrobots.com/robotforum/index.php?topic=7206.0 help? do you want to control them individually or all together?

offy · « **Reply #2 on:** March 13, 2009, 08:10:19 PM »

together. When my robot gets power, and I flip a switch, the LED's will light up.

paulstreats · « **Reply #3 on:** March 13, 2009, 08:19:55 PM »

The connectors that are on the LEDs are likely to be their normal legs. These are supposed to be soldered to something, they arent really designed as socket connectors.

With them being blue led's, you might not get them working straight from the microcontroller. I havent used blue LED's for 3 - 4 years but I remember having to use a seperate circuit to provide power for them(maybe they run on less power now?).

I dont think you are going to get off soldering duty that lightly

SmAsH · « **Reply #4 on:** March 13, 2009, 08:22:42 PM »

yes paul, blue leds still use more power than the others. you may get off soldering but then you will have to crimp them into a connector.

offy · « **Reply #5 on:** March 13, 2009, 08:35:27 PM »

I have a bread board I could do some testing on. Can I have direct power to the LED's, and if so, how much power.

I am new to all of this wiring, and circuits. Thanks so much for the help.

pomprocker · « **Reply #6 on:** March 13, 2009, 08:53:09 PM »

solder a 330ohm resistor on the anode and cut the lead of the resistor and the led so they are flush. Then you can crimp female connectors on it just like you do with making a sensor cable conector

I did this technique with a 0.1uF cap on the reset line

SmAsH · « **Reply #7 on:** March 13, 2009, 09:01:23 PM »

wait one thing i forgot to ask, do you just want it to light up or do you want to have the microcontroller light it up?

offy · « **Reply #8 on:** March 13, 2009, 09:02:25 PM »

I am going to make a LED board. How much power should I have for 3 LED's (blue) and what is anode? Does the resistor go on the + or - of the LED?

I just want the 3 led's I am adding to light up.

*EDIT* I added a picture of what I plan on doing.

Brown = Battery
Red = Wire +
black = wire -
The box with / = Switch
Blue = LED

The wires leaving the lights going to the - of the battery do not cross the other black wires.

pomprocker · « **Reply #9 on:** March 13, 2009, 11:43:44 PM »

always confide in the wizard

http://led.linear1.org/led.wiz

Solution 0: 2 x 1 array, 1 extra LED
+----|>|----|>|---/\/\/----+ R = 56 ohms
+----|>|----------/\/\/----+ R = 150 ohms

The wizard says: In solution 0:
each 56 ohm resistor dissipates 22.4 mW
the wizard says the color code for 56 is green blue black
the wizard thinks ¼W resistors are fine for your application
the 150 ohm resistor dissipates 60 mW
the wizard says the color code for 150 is brown green brown
the wizard thinks ¼W resistors are fine for your application
together, all resistors dissipate 82.4 mW
together, the diodes dissipate 120 mW
total power dissipated by the array is 202.4 mW
the array draws current of 40 mA from the source.

Solution 1: 1 x 3 array uses 3 LEDs exactly
+----|>|---/\/\/----+ R = 150 ohms
+----|>|---/\/\/----+ R = 150 ohms
+----|>|---/\/\/----+ R = 150 ohms

The wizard says: In solution 1:
each 150 ohm resistor dissipates 60 mW
the wizard says the color code for 150 is brown green brown
the wizard thinks ¼W resistors are fine for your application
together, all resistors dissipate 180 mW
together, the diodes dissipate 120 mW
total power dissipated by the array is 300 mW
the array draws current of 60 mA from the source.

Razor Concepts · « **Reply #10 on:** March 14, 2009, 03:53:30 AM »

Use the solution 0 or solution 1 wiring that pomprocker posted. The wiring you drew up (1 resistor with 3 leds in parallel) will cause the LEDs to burn out more quickly.

offy · « **Reply #11 on:** March 14, 2009, 05:41:33 AM »

Solution 1 looks like a better choice.

Could I modify my circuit by adding 3x 150 ohm resistors before wire touches the light?

SmAsH · « **Reply #12 on:** March 14, 2009, 05:54:31 AM »

yes you could solder them onto the board if thats what you mean.

offy · « **Reply #13 on:** March 14, 2009, 06:13:57 AM »

Is this new diagram right. The red blocks are 150 ohm resistors.

SmAsH · « **Reply #14 on:** March 14, 2009, 06:37:41 AM »

yea that looks alright, still dont see why the switch is there tho?

offy · « **Reply #15 on:** March 14, 2009, 06:40:55 AM »

I am going to have this on a different power supply than robot. So I can turn it on and off when I want to use it.

madchimp · « **Reply #16 on:** March 14, 2009, 07:18:56 AM »

If you are using a separate power supply and a switch to manually operate the LEDs where does the roboduino come in? The way you are setting it up as explained it's not even connected.

offy · « **Reply #17 on:** March 14, 2009, 07:25:16 AM »

I was going to hook it to the robotduino at first, than I decided not to.

offy · « **Reply #18 on:** March 14, 2009, 02:04:19 PM »

It does not light up (LED) I have a single AA battery, through a 330 ohm resistor, to LED, than back. It does not work... Please help me.

Razor Concepts · « **Reply #19 on:** March 14, 2009, 02:18:37 PM »

A single AA battery doesnt have enough voltage to light a LED up. The info pomprocker posted was for a 5v power source.

offy · « **Reply #20 on:** March 14, 2009, 02:22:19 PM »

Oh, I need atleast 2.1v for this LED. I am going to go out, buy a 2x AA battery pack (3v) and than I will be on my way.

pomprocker · « **Reply #21 on:** March 14, 2009, 05:59:26 PM »

You're not listening...use the LED wizard!!

The led's have a forward voltage of 2v usually, how are they suppose to get that with only 1.5v?

And if you did only give it 2v source voltage, you would only need 1ohm resistors not 330ohm

the 330ohm resistors are for 5v source voltage

Use the wizard!!

http://led.linear1.org/led.wiz
http://led.linear1.org/led.wiz
http://led.linear1.org/led.wiz

In fact, read everything on that site!!

SmAsH · « **Reply #22 on:** March 14, 2009, 06:22:46 PM »

lol pomprocker. if you want to use the 330ohm resistor for whatever werid reasons go make yourself a 5v battery pack or better yet connect it up to your pcs usb port! and if you ever forget the wizards web addy and because its good to know. R=(v1-v2)/A. V1=(VIN) V2=(VDROP) A=(current in amps)
in your case. 5-2/.02=150? anyone know the correct name for vdrop? load or something?

offy · « **Reply #23 on:** March 14, 2009, 06:26:40 PM »

I got it, thanks for the help.

pomprocker · « **Reply #24 on:** March 14, 2009, 06:51:40 PM »

Blue LEDs also have a forward voltage drop of 3.3v, Red LEDs only need at least 2v. See the wizard.

LOL

SmAsH · « **Reply #25 on:** March 14, 2009, 07:28:05 PM »

quite you! stop making him want more batteries!

offy · « **Reply #26 on:** March 14, 2009, 07:57:21 PM »

I picked red, because Radio Shack didn't have any blue.

SmAsH · « **Reply #27 on:** March 14, 2009, 08:10:23 PM »

they generally dont have blue unless its for about $1.50 a piece

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Author Topic: LED's on the Roboduino. (Read 2566 times)

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