Questions tagged [led]

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

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39
votes
5answers
55k views

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?
65
votes
7answers
51k views

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 ...
12
votes
2answers
31k views

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,...
19
votes
3answers
25k views

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 ...
2
votes
3answers
45k views

Why Isn't My Ethernet Working?

I just got Pi Model B. I downloaded Wheezy on SD card and plugged in all of my cords. Everything works fine except the Ethernet port. The LINK LED flickers for a second while booting up, but then it ...
5
votes
1answer
6k views

Is my Pi's GPIO damaged?

I am trying to test GPIO output on a Raspberry Pi, and I am wondering if it is broken. These setups work: 3v3 >> +LED terminal -LED terminal >> resistor >> GND (the LED is unusually dim here) 3v3 >>...
10
votes
2answers
3k views

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 ...
2
votes
3answers
11k views

Is it possible to connect an LED directly to the GPIO of the Pi?

I was wondering if it is possible to connect an LED directly to one of the GPIO pins of the Pi? The reason I ask is that, I have read from many sources that if I am not using some sort of break out ...
4
votes
1answer
1k views

Powering and controlling hundreds of LEDs with a Raspberry pi

How do you utilize the Raspberry PI to be able to power hundreds of LED lights? Imagine I have Christmas Lights (LED) and I want to be able to control all individually (write a program on the ...
1
vote
2answers
5k views

Python - One momentary switch, LED, and a shut-off timer

I'm working on programming a LED strip lights application that is activated with a momentary push button and if the lights are not turned off by the push button, then they automatically turn off after ...
4
votes
1answer
688 views

Can't get LED to turn off

I'm a rookie with Raspberry Pi and electronics in general. I was able to get my LED to turn on when I plug it into the breadboard but i'm unable to get it to respond via Python or wiringPi. The LED ...
4
votes
1answer
713 views

Powering WS2812B LED strip from Pi brownouts

I have a Raspberry Pi 3 Model B currently controlling and powering a strip of WS2812B LED's. A separate 5V 15A power supply powers the Pi through pins 2 and 6, while the LED's are powered off of pins ...
2
votes
4answers
2k views

Red LED after `sudo halt`, may I unplug?

I flashed Raspbian and I use my Pi headless, connecting via SSH. To power it off I do sudo halt, which disconnects me from the SSH. After a few green led blips I have steady red led on. Does it mean ...
2
votes
1answer
717 views

LED resistor question

I'm fairly new to electronics and I'm in the process of creating a IR Birdbox using a Pi Zero and IR Camera. I have a quick question regarding the correct usage of Resistors for IR LEDs (Or any LEDs ...
33
votes
1answer
82k views

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 ...
7
votes
5answers
24k views

Which addressable RGB LED strips are beginner friendly and Raspberry Pi friendly?

I'm programmer and my electronics knowledge and soldering skills are pretty basic. I want to find a bright, addressable (a.k.a. digital) RGB LED strip which can be attached to RPi and programmed ...
12
votes
2answers
3k views

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 ...
5
votes
3answers
695 views

Is there an addressable LED product that I can wire to a Raspberry Pi where all the LEDs are separate?

I have a RPi project where I want to build but alas I'm a programmer, not an electrical engineer. I can solder things, but I couldn't tell you what resistor I needed to put where. Anyway, I looked ...
3
votes
1answer
990 views

Powering up a WS2812 led strip with different power supplies

I have a Pi powered with its own adapter. I bought a 1 meter ws2812 led strip and bought a separate power supply for it (5V 6A). I plan to plug the +5V of the power supply directly to the +5V section ...
0
votes
3answers
165 views

How complicated is it to light an LED?

I have been trying to right my first physical script, to simply light an LED. I HAVE BEEN DOING HOBBY ELECTRONICS FOR A WHILE, and lighting an LED is simple. Wanted to use Pi to light LED, but I can'...
10
votes
2answers
5k views

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 ...
5
votes
3answers
4k views

Connecting blue LED (3.3V)

I've recently started doing basic diode connections (red and green diodes). I've also got blue diodes, but there's one thing that prevented me from connecting them already, namely - the specs say they'...
4
votes
2answers
3k views

Read status of power led using sysfs

I want to read the status of GPIO35 on a Raspberry Pi 2 Model B using the sysfs on Raspbian with a 4.0.8-v7+ kernel. I can access other GPIO pins using /sys/class/gpio but the two leds are already ...
4
votes
1answer
8k views

Why can't I turn on an LED through Python?

I have an LED connected to pin 11 on the Raspberry Pi header, (also known as BCM/GPIO pin 17, and GPIO0). I have installed the Raspberry Pi Python library according to these instructions. Attempt 1 ...
4
votes
1answer
749 views

GPIO stuck in High Mode

I'm new to this whole RP world, and I'm trying to learn it. I've been trying to follow this post, and connected my Pi this image below Connection between Pi and Adafruit T-Cobbler Plus Wiring ...
3
votes
2answers
1k views

Powering several LEDs from GPIO output

I'm currently working on a "rotating cube" project where a raspberry pi will be used to determine which cube face is at the top and any given time using an accelerometer and light it up with LEDs. So,...
2
votes
1answer
705 views

Model B+ i2c issues with 7 segment display

I purchased a 4 digit 7 segment display from adafruit and got it working on my old model A running adafruit occidentalis operating system. I recently bought a model B+ and installed the latest version ...
2
votes
1answer
611 views

Other hardware for camera slots?

I think the raspberry should get more cool hardware like the camera that works with the slot onboard. I'd love to get a fast RS485 onto this slot because i need all my GPIOs for LEDs. Currently I use ...
1
vote
3answers
3k views

'Zoom out' on 3.5 inch LED screen

I bought a 3.5" LED screen that is on my Pi, however it is nearly impossible to use because edges of windows are clipped off etc. How can I 'zoom out' so that all the windows are really tiny? ...
1
vote
1answer
696 views

extend the current for PWM LED Control

i am using the raspberrypi to have 2 led's fade up and off. My script works and its ready to go. But i need to get my LED's brighter. Is there a way to extend the GPIO Current of the rasperry pi ? ...
1
vote
3answers
532 views

I'm looking for a serial input type “polychromatic” LED as an output for my raspberry pi. Does such a device exist?

Forgive any potential neologisms, but I would like to acquire a light that can, say, display 64-256 different shades of color based off of a digital numerical input signal? It can be a usb light, but ...
1
vote
2answers
655 views

Why won't the LED turn on?

Here is the code I am running on the Pi through IDLE. import RPi.GPIO as GPIO import time GPIO.cleanup() GPIO.setmode(GPIO.BOARD) GPIO.setup(12, GPIO.OUT) for i in range(50): GPIO.output(12, 0) ...
0
votes
2answers
837 views

LED strip has R-G-B instead of DI and CI

I went and bought an LED strip which has the following labels +V R G B How does this correspond to another naming scheme I have seen which looks like so: GND DI CI +5V I could use this tutorial, ...
0
votes
1answer
1k views

What GPIO pins are required to Power RPi? [duplicate]

We are using Raspberry Pi Model B: We used USB connector from PC - confirmed output - 5V, with 2 leads: Connected +5V to Pin 2 Connected GND to Pin 6 on connector - Inserted Ethernet cable ...
-3
votes
1answer
947 views

Using led screen of a mobile phone on raspberry pi [closed]

I have an old led panel (ONLY) from my old phone. I was thinking about the way to connect it to my raspberry pi 3 and use it as its screen. Is it possible? If i could, what should i do. Thank you all ...