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

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SenseHat; Random Pattern using FrameBuffer: No Error?

This Raspberry Pi Post talking about the SenseHat gives the following example to fill up the LED matrix with random colours: cat /dev/urandom > /dev/fb1 This works: but also generates the ...
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1answer
29 views

Connecting 32 pin LED matrix to Raspberry Pi

I have a Raspberry Pi Model A and a 32 pin 8x8 full color LED Matrix. I would like to connect these up so my Raspberry Pi can control all the LEDs. This is the LED matrix I have: ...
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22 views

Flash LEDs connected via GPIO to beat of music [on hold]

I would like to flash the LEDs connected to my Raspberry Pi 2 via GPIO to the beat of (MP3) music. Is there any way to do this? I've found a few tutorials for the Arduino but none for the Raspberry ...
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4answers
146 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 ...
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2answers
27 views

Wooden clock with LED: which components?

I would like to make such clock: It should be composed of several big squared dots If you check, there is no holes, I guess it's only a fine fake wood that is glued above It should have a minimum ...
3
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1answer
543 views

I need to control 8 LED's but I can only control 3? [helpful pictures attached]

I'm very new to electronics in general, but I want to build a small project where I can individually control (from a GPIO pin) 8 LED's. From what I understand, each GPIO pin on the Pi (Pi2 model B ...
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1answer
113 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 ...
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1answer
25 views

I have an LED scoreboard that no longer connects with its remote, would it be possible to mod it to run over wifi being controled by a RPi

I was wondering if this type of scoreboard could be controlled by a pi wirelessly as the wireless remote has stopped working.
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1answer
75 views

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 ...
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1answer
73 views

Problem using Buttons to swich LED's on and off

Im making a prototype of a model lift shaft. The LEDs in this example will eventually be replaced with relays. Side Note For those who do not know, a limit switch is a microswitch plces at the ...
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3answers
759 views

Using jumper cables to turn on LEDs

Currently I have my LED's anode connected to the GPIO pin that controls it and the cathode is attached to a resistor and the other end of the resistor is on my breadboards - rail. How can I use jumper ...
3
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1answer
119 views

Help lighting LED via GPIO pins

So I got an RPi and a canakit, I'm trying to follow a guide to get a simple program to make the LED blink. I have very little experience with RPis so it's probably a very simple error, but I can't ...
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1answer
42 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 ...
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2answers
97 views

How do you connect 81 LEDs to as few pins as possible?

A friend and I are trying to make a chess board where you play against a chess engine. The move the chess engine plays is shown by lighting a few LEDs on the board and you have to move that piece to ...
4
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1answer
74 views

Why is my LED display code so slow?

I have a Raspberry Pi 2 and I am trying to create an led display for it from scratch. It works.. but the refresh is far to slow. My project is running very very slow averaging around 21 ms per ...
2
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2answers
58 views

On-board LED connection to GPIO

I stumbled on this tutorial: http://www.cl.cam.ac.uk/projects/raspberrypi/tutorials/os/ok01.html Unfortunately this is only made for the B rev2 board, whereas I got a B+ board and the board setup is ...
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0answers
24 views

Synchronize Pi Camera and LEDs

I have a Pi Camera (NoIR) and two sets of LEDs, A and B. The two sets of LED are different in position and wavelength. I want record video with the Pi Camera so that any consecutive frames be lit by ...
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0answers
41 views

How can I set up a chain of these RGB Smart Neopixel LEDs?

I have these LEDs with me. At the end of the day, I need to connect around 100 of these together, with each one being individually programmable. I was testing connected the four of them I have ...
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0answers
29 views

max7219.led no such module

After running: sudo python max7219/examples/matrix_test/py I get the error: Traceback (most recent call last): File "max7219/examples/matrix_test.oy", line 3, in <module> import ...
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3answers
275 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 ...
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0answers
25 views

Why wont my LEDs display when Brightness is turned down using Hzellers library?

I have 4 16x32 Led matrixs chained to display output from my Raspberry pi using Hzellers led matrix library. Link: https://github.com/hzeller/rpi-rgb-led-matrix. I want it to display at 25 percent ...
3
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1answer
168 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 ...
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0answers
33 views

Led animation controlled via GPIO input

I would like to control Addressable LED animations with the press of a button. The following code works, However, I have to press until the current animation finish its rotation before i can launch ...
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1answer
61 views

SenseHAT: get_pixel() function

I have been making a maze game on the SenseHAT in Python. I am trying to not let the player move through walls, but it just erases them. It should use the get_pixel() function to check if the player ...
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2answers
100 views

Turn LED on after a particular time for a particular time period

I am doing a small project which consists of turning LEDs on and off using the GPIO library. I am able to successfully turn the LED's on and off using a browser on my laptop. But now I want the LEDs ...
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2answers
39 views

Is it safe to drive a current between a GPIO output at 0V (LOW) and the 3.3V supply?

Normally I would drive a current between a GPIO output at 3.3V (HIGH) and GND, for example to light a LED (with a resistor included of course). I am now wondering if it is safe to drive the current in ...
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1answer
85 views

Can't get Raspberry Pi to Control LED Lights

I am currently trying to get my Raspberry Pi to be able to control my RGB LED Strip. Here is the guide I am using: https://popoklopsi.github.io/RaspberryPi-LedStrip/#/. Currently, the LED Strip lights ...
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2answers
103 views

Raspberry pi 2 heats and does not boot (Power LED doesn't glow) after over-current dmesg

I was using my pi as a wifi router using USB wifi adapters and saw "USB over-current messages". I removed the USB devices and over-current messages stopped. however after some time. Pi restarted and ...
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1answer
114 views

Why are my LED colors in GRB and not RGB?

I'm using a Pi to drive a Fadecandy board to light up a varying-length string of RGB LEDs in different, pulsating colors. I've been successful, however one snag I ran into along the way was ...
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2answers
108 views

My GPIO is not working correctly

I have a raspberry pi 2 and trying to build a simple led circuit where a light turns on (so one of the most basic circuits). I am following this tutorial: ...
2
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2answers
94 views

Connection to raspicam as event trigger

I have a NoIR cam working with my Pi2 using the uv4l driver. I also have an external 12v IR led array that I would like to set up with the Pi. My plan was to set up a Pi controlled relay to turn on ...
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1answer
83 views

Why won't `gpio` work from an init script?

I have an init.d script that successfully runs scripts to an LED board from Adafruit using this software: https://github.com/hzeller/rpi-rgb-led-matrix In addition, I've set up a simple single LED ...
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71 views

Increase Performance of 4x4 LED Matrix (Multiplexing with pi4j)

I have coded a Display-Class to drive a X by Y LED-Multiplexing-Matrix with pi4j. However, I when driving a 4-by-4-Matrix I cannot get the framerate beyond roughly 30 fps, which still produces a ...
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1answer
62 views

Pi randomly dies after few days, stops responding and blinking green LED continuosly

When rasp is under heavier load (eg. copying tb of data over ssh for few hours) it recently started to randomly die without response. syslogs don't tell much. Not overclocked, fan attached. led ...
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0answers
66 views

What's the best way to control a Matrix of 10 x 20 LED with Raspberry Pi?

I developed a Tetris-Clone in Java. I want to run it on the Raspberry Pi and display it on a 10 x 20 Home-made-LED-Matrix. My question is: What is the best way to achieve that. Here are the solutions ...
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2answers
295 views

Connecting WS2801 LED strip to my Raspberry Pi

I'm new to the Raspberry Pi community and to working with electricity, so I'm looking for some advice. I've brought the WS2801 LED strip from eBay (but I think it's the same as this: ...
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2answers
56 views

Raspberry Pi not booting and all LED is dead (also the red LED)

as the title suggest, I am having a problem with my raspberry pi. It's a raspberry pi B+ 512Mb. the power is plugged in ( I've tried several power supply) no LED turns on (including the power ...
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1answer
43 views

Attached LEDs to GPIOs 18, 23, and 24, using JavaME 8. 18 and 24 work, but not 23. Why?

I'm new to Raspberry Pi and I have just figured out how to use Java to power LEDs. However, I cannot get GPIO 23 to work. This is my wiring setup. Here is the java code I am using to power the ...
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2answers
108 views

The power LED will not light- power supply is fine

The power (red) LED on my pi will not light. It was working fine, but then suddenly, while I was using it, poof! At first it blinked occasionally, now it just won't turn on. The power supply was as it ...
4
votes
2answers
340 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 ...
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0answers
30 views

Problem with hardware on raspberry A+ [closed]

i have a uncomond issue... first of all, is not the hardware i guess, because, with code, i can turn on/off the leds... connecting a buttons and setting inputs is when i have a trouble... for example ...
3
votes
2answers
824 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 ...
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0answers
37 views

Half size breadboard problem

I purchased the Raspberry Pi YouTube Workshop Kit from Buy a Pi.com a few days ago. I have a B+. But when I completed tutorial number two, LEDs On and Off, only the LED on the right turned on. Then I ...
3
votes
2answers
169 views

Red LED blinks twice on boot with 5V/5A power adapter!

I use RPi B+ for playing a folder of videos automatically after boot. But the problem is that during the initial boot, the red LED on the board blinks 2 times (one after 4-5 seconds of boot, and the ...
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0answers
98 views

Spi and WS2801 problem on the raspberry pi

I have bought a couple of these led strands from adafruit. http://www.adafruit.com/products/322 they use WS2801 chips. I have a raspberry pi B+ running raspbian I have been having problems ...
3
votes
1answer
2k views

Using PWM in a Windows 10 App with the Raspberry Pi 2

I am a newbie an I have succesfully use a RBG Led, and I emulated PWM by code but it is too slow (and in somehow the timer autostops), Then I watched that the standard libraries support GPIO.PWM but ...
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2answers
108 views

Controlling 64 parallel LEDs using using Raspberry Pi

I have 64 LEDs connected to one another using a single long wire. I want to control each LED individually to create patterns of lightening. And I am using GPIO pins to achieve that. I search but ...
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0answers
113 views

Led - Manual control of WS2801 chip

I'm wondering if there's a way to manually control a multicolour LED strip powered by a WS2801 chip, i.e. being able to type a bash command from raspbian or any kind of software control, something of ...
3
votes
1answer
365 views

RGB LED is not lighting up

I connected an RGB LED(common anode) via the GPIO, and tried to get it to light up, but for some reason when I run the command, the LED does not light up. Here's the code I'm using import RPi.GPIO ...
0
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1answer
139 views

How to measure the frequency of the audio output

I was wondering how I can measure the frequency of the audio output of my raspberry pi. Currently I am trying to create a script to control an RGB led to the music that is being played through the ...