I have an led on my shield

how do I access it? This also goes for the button on the shield, as well...

And what's the plus to have a resistor on your shield/

Insufficient information. Exactly what shield do you have? Where is the schematic for it?

"Insufficient information." Sorry about that... New to this.

This is the shield http://www.r3cube.com/A-Ric/regan/ardo-prototype-diy-wboard-3.JPG How can I access LED1 OR S1 (BUTTON)?

From the schematic (http://www.ladyada.net/images/pshield/v5schematic.png) it looks like two LED's and S1 are not connected to any pins. Look for the slightly larger holes near the devices. Connect the LED hole to +5 or a HIGH output pin to light the LED. The S1 switch connects its hole to Ground. To read it, connect the hole to a digital pin. Set the pin as an INPUT and use digitalWrite(pin, HIGH); to turn on the internal pull-up resistor. When you do digitalRead(pin); a value of 1/HIGH/true will mean the switch is open. A value of 0/LOW/false will mean that the switch is pressed.

nate890: And what's the plus to have a resistor on your shield/

Possibly to restrict current flow and keep from burning up something like a led.

Do you know Ohm's Law yet?

"Possibly to restrict current flow and keep from burning up something like a led." Yeah, yeah, thought that through, but figured that you'd need a ton of current to mess up something on the shield.

Thanks, John

How would I connect it to a DigitalPin?

Nevermind! I see what you mean... Connected a jumper cable to the hole under the LED.

This is the third post, in three different parts of the forum, about your LED and your shield.

Please choose where you want to post, and stick to that thread. It's just confusing for everyone otherwise.

One thread locked, the other deleted.

  • Moderator

The third one? What?

nate890: "Possibly to restrict current flow and keep from burning up something like a led." Yeah, yeah, thought that through, but figured that you'd need a ton of current to mess up something on the shield.

Thanks, John

Not really. 5V without at least 180 Ohms resistance will take out a red led soon enough. I can pop leds with 3V, probably less.

Leds are not the only tender parts. If you let too much current be drawn from a pin then bye-bye pin, which 5V is easily capable of. You also need to keep the total draw through the Arduino down to about (IIRC) 200 mA or risk toasting the chip which is made as a low consumption device.

Hmm.. I was playing with a IR remote receiver and I think I blew it. Thanks for the future advice!

Done that. It made a 'funny' smell. Ooops!

There's some electronics to learn unless you only follow 'cookbook recipes'. But it's digital electronics you can get by on and not the harder stuff at least until you get harder ideas, hehehe.

1st thing to learn is Ohm's Law, the relationship between voltage, resistance and current. Knowing that, you can learn more. Without it, you can poke in the dark and burn parts up.

“Done that. It made a ‘funny’ smell. Ooops!” Yeah, I can relate… I thought the solderer was still on :S It also got extremely hot. Haha, now the remote that I got just to get the receiver is useless.

You can buy just the parts you need. When there's shipping charges it's best to buy enough to justify those, so watch for those. You can get cheap or free shipping and great prices from China if you are willing to wait 3 weeks for your stuff.

one of these might do: http://www.mouser.com/Sensors/Optical-Sensors/Photodiodes/_/N-9xeto/

or one of these: http://www.mouser.com/Sensors/Optical-Sensors/Photodetector-Transistors/_/N-9xesa/

or this: http://www.allelectronics.com/make-a-store/item/PTR-4/PHOTOTRANSISTOR/1.html

There's lots of places to buy just the parts you want.

“There’s lots of places to buy just the parts you want.”

Yeah, getting quick sick of shopping off of ebay. Do you know any stored in Canada that might sell things for Arduino? I know stored like The Source or Futureshop never sell anything for circuits and such…

There's Canadians who mention 2 places at least, DigiKey might have a place in Canada. You could start a thread down in Bar Sport asking. Or you can find the purchase thread and skim through 19 pages of that, there's lots of parts sources mentioned. http://arduino.cc/forum/index.php/topic,91399.0.html

I rarely do eBay. Allelectronics, Mouser, DigiKey, and many others are parts houses and they do sell pretty much worldwide. Allelectronics is kind of a salvage and overstock place with some strange items, an interesting catalog and decent prices, Mouser and DigiKey are full-service new parts. I got 4 328P-PU chips (Arduino UNO chip) for only US$2.08 ea from Mouser just last week which really ain't bad. And they have nice catalogs too.

EBay.... a good place to buy things you're not sure of but occasionally you can turn up gold. Focalist calls it bottom-feeding and comes up with some real winners.