Raspberry Pi Stack Exchange
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Questions tagged [led]

An LED, a light emitting diode, is a light source often used as an indicator.

The onboard LEDs of the Pi (depending on the model): POWER, OK, FDX, LNK and 10M are discussed at How do I control the system LEDs using my software?

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How do I control the system LEDs using my software?

There are 5 LEDs on the RPi: OK, PWR, FDX, LNK, 10M. I'd like to know if it's possible to control any of these from software i.e. turn them on, or change intensity (or even change colour gasp). And if so, where can I read up about it? The LEDs could…
Maria Zverina
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What do system LEDs signify?

There are 5 status LEDs on the Raspberry Pi board. While I can guess what the POWER LED signifies (the power being attached), I am not sure about other four. So, what do OK, FDX, LNK and 10M signify?
user13
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Why is a resistor needed for LEDs?

While looking for a basic task to get familiar with the Raspberry Pi and its GPIO pins, I decided that driving an LED sounded simple enough. While investigating how to go about this task I've noticed that most instructions indicate to place a…
Jason Whitehorn
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What do the LEDs on the B+ mean?

Not a duplicate of this RPi.SE question, as I'll explain in a moment. GPIO.RPI_REVISION returns 3. As far as I can tell, looking at my B+, there are no LEDs labeled: OK, FDX, LNK or 10M. There are two embedded in the Ethernet port, and two on the…
PythonNut
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Why are some GPIO pins HIGH when the Raspberry Pi boots up?

I have an easy circuit wired up, with an LED connected to pin 18 on the BOARD reference. I run a simple program to put pin 18 to HIGH, which turns the LED on, and then a couple of seconds later, I set pin 18 to LOW, and finally I end my program with…
Viktor Raspberry
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Wiring RGB LED's

I was wondering if it is possible to connect 8 individual RGB led's much like the adafruit strip. I saw the Pumpkin Pi project and would like to build one. I don't have any yellow or red LED's, but have a small stockpile of the RGB's. I know for…
atrueresistance
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What do I need to simulate traffic lights using LEDs?

So I'm making a model that simulates traffic lights (Red, Amber, Green) so there will be three LEDS that need to be preferably extendable (I don't want them attached directly to the breadboard) but I don't even know where to start (Ok, I admit I am…
Phorce
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Disable LEDs Pi Zero

Can I disable the yellow (PWR?) LED on the Pi Zero? I've tried setting the brightness to 0 of led1 (it starts life as 255) and led0 is already 0 but I still get the LED glow. Out of interest, I only managed to set the brightness file to zero by…
Toby
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Controlling many LEDs with few GPIO pins

I successfully completed my hardware "hello world" using this guide: http://www.raspberrypi-spy.co.uk/2012/06/control-led-using-gpio-output-pin/ Now I'd like to move on to bigger and brighter things, more individually controlled LEDs that is!…
SkyNT
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Visual/audio status/activity indicators

What, if any, indicators of system status or activity are available on the Pi? Audio - I'm talking about a beep when it's turned off, or a series of beeps indicating POST information, etc. Video - Does it have a power on LED? What about a disk…
stuffe
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How can I turn the lights off on my pi?

I'd like to build a small internet radio out of my pi, but I'd like to use it at night, when the flashing LEDs would be disturbing. Is there any way to disable them?
Tom Medley
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What's the Difference between Raspberry Pi and Arduino?

This question stems from a large lack of understanding, but it concerns a project I've wanted to do for a while. This is an Instructables page for an 8x8x8 led cube, and the 70th step addresses the question, "Can I use an Arduino to control the…
SomekidwithHTML
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Controlling 400 LEDs from a raspberry pi

I have a client who has several large bronze signboards, each with 100-150 little light bulbs on it, totaling approximately 400 bulbs. The bulbs are turned on and off on a schedule, currently by hand (partially unscrewing the bulbs that are not…
Moshe Katz
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Is there any built in LED connected with GPIO pin?

In Arduino a built in LED is attached with number 13 Digital pin. Is there any LED like Arduino in Raspberry Pi,which I can use to test my code?
Sohan Arafat
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How to blink LEDs on/off continually, while continuing execution of a script?

I've connected red and green leds via GPIO and I can successfully switch them on/off using RPi.GPIO - now I'd like to: start an led blinking on/off every 1 second have the script continue its execution stop the led from blinking on another…
Stephen Lead
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