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

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Making an LED Cube

I've recently bought my Pi. After being satisfied of deploying my Enterprise Scale Java Applications (yes I actually deployed some production ready stuff on a toy instead of a real staging server), I ...
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34 views

A simple java program for led blinking [closed]

I am a new user of Raspberry PI 3 and this question might be stupid for a lot of users. I want to build a simple Java software able to blink a led connected to a raspberry GPIO pin.
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106 views

Board sign from LED strips

I'm trying to build a sign board made of LED strips, just like this I found a ton of examples on controlling a single strip and also examples using the adafruit premade led boards (16x32), but no ...
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1answer
37 views

Error when sending second start command to Cylon.js to blink LED

Using Node.js, express and cylon.js, I'm getting a post request and blinking an LED using a raspberry Pi. I receive the first post request fine, the code runs and the LED blinks. However on the second ...
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22 views

LED not Blinking using nodejs and python

I am using Raspebrry Pi3 with node js and when I run this command sudo node index.js it is running fine but not blinking the LED. I am using GPIO-17 pin and I follow the same instructions as given ...
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2answers
109 views

LED Toggle Switch with GPIO

I have a raspberry Pi 3, and am looking to use a 3 wire automotive LED switch (think missile switch or lighted rocker switch) to trigger a GPIO pin, and power the LED when in the on position. If I ...
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1answer
65 views

SPI control of WS2801 LEDs, fails when using GPIO interrupts

I have three libraries (is library the right word?) that I'm using in my Python code: An Adafruit NeoPixels library, which comes from the rpi_281x library to control them via PWM, on GPIO pin 18. ...
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47 views

LED button doesn't work

I have tried connecting a LED with a button like this (from "Adventures in RPi"), but with the far end of the button plugged at G (instead of F). And I ran it with the following Python program (by ...
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71 views

Raspberry Pi 3 Interactive Led Strip Wall

At the moment we're working on an interactive led screen wall for the entrance hall of our new studio. I've setup the following frame with 17meters of WS2812B addressable led strips.We're using the ...
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16 views

Raspberry Pi Restarting When GPIO Pins Touch [duplicate]

I'm a newbie to raspberry Pi and electronics in general. I was trying to get a LED turned on by connecting a wire from 1 (3.3) and 6(Ground). But when the pins touched each other the Pi restarted, why?...
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1answer
62 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 ...
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1answer
25 views

LED on gpio from old pc

Just a quick question, I just took apart an old pc and it has a simple power led. It was attached directly to jumpers on the mother board (power led, activity led and hdd led) Can I use it on the RPi ...
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49 views

RPi GPIO and if statements

I'm writing a code that translates a raw input into binary, then displays it on LEDs connected to the GPIO pins. This is my code import RPi.GPIO as GPIO import time def on(pin): GPIO.output(pin,...
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133 views

Green LED never lights up

When I power up my Raspberry Pi 3, the red LED lights up and stays red until I unplug it. The green LED always stays off no matter what: - I tried 3 different 2A chargers - I tried 2 different SD ...
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35 views

My Pi boots and runs Raspbian but in 1 or 2 minutes from running it it turns off and I have to reboot and reinstall everything

I have to reinstall NOOBS in the SD again every time. Also it tries to boot after it turns off but it then goes off again.
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3answers
103 views

False positive press of a button

I've got a problem with my circuit builded with my raspberry pi B rev 1. I've got a button which press triggers a function in python, triggered with the line GPIO.add_event_detect(7, GPIO.FALLING, ...
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1answer
85 views

RPi 2 GPIO LED wont turn off! [duplicate]

I Set up one LED on GPIO port 17 and turned it on with the following code : import RPi.GPIO as GPIO GPIO.setmode(GPIO.BCM) GPIO.setwarnings(False) GPIO.setup(17,GPIO.OUT) GPIO.output(17,GPIO.HIGH) ...
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2answers
261 views

How can I control the red LED again

I just acquired the latest Pi-3. In the Pi B+ and Pi 2 it was possible to access both the red and green LED through /sys/class/leds/led0 and /sys/class/leds/led1. After setting up the Pi 3, I have ...
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1answer
238 views

I can't get three LED lights to turn off and on in an order

I'm setting up 3 LED lights to turn on automatically in a specific order using a Raspberry Pi 3. I coded it with Python. At first I had two and it worked. Then, I added a third with the same program ...
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106 views

Control PWR and ACT LEDs on Raspberry Pi 2 B from Python

I want to control the PWR and ACT LEDs on the Raspberry Pi 2 B using a Python script. I found these lines but I don't know how to implement it in Python, can anyone help me please? # Set the PWR ...
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61 views

No video output on Raspberry Pi Zero, LED flashing

So I just got a Raspberry Pi Zero and an SD card with NOOBS pre-installed. I placed the SD card onto the RPi as well as a keyboard and a power supply. I plugged the RPi onto two different monitors, ...
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1answer
68 views

How can I fix this spidev time out error?

I am writing a Python class that will combine control of two different types of RGB LED "pixel" strands from a RPi. You can see all of my code here on Github. I will quote the relevant code here, but ...
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3answers
59 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? ...
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1answer
53 views

Lighting 5050 led and learning to use spi

I'm just getting started trying to figure out how the whole spi thing works. I'm using an apa102 led as I figured turning on and off leds and setting colours would be a good start. I bought the ...
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76 views

Controlling multiple Digital LED light strip through Servo hat/driver

After gathering some requirements in my project, I thought that it should be possible for us to control multiple LED Light strip through a servo hat (Considering that we are able to provide enough ...
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2answers
55 views

Different voltages across circuit when 3v3 to ground than when 3v3 to GPIO in

I have built a small Morse code key that consists of a push button, a 3v buzzer and an LED. When I connect the positive side to 3v3 and the negative side to ground, the key works. I push on the button,...
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119 views

How to indicate read / write disk operiation via LEDs connected to GPIO

I think I know how to connect LEDs to GPIO but I want to illuminate them when there is read / write operation to sdcard or other mass storage connected to Pi/ Is it possible ? I am doing little ...
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77 views

Driving 32x32 LED grid via GPIO preventing other processes from running

I have a project running a 32x32 LED grid based on these instructions: https://learn.adafruit.com/adafruit-rgb-matrix-plus-real-time-clock-hat-for-raspberry-pi/driving-matrices which relies on these ...
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57 views

Blinking LED - start and stop

This is my first post here so HELLO and sorry if I'm posting in the wrong place. Do you know a simple bit of Python that will set a LED blinking indefinitely until it's told to stop? Control will be ...
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16 views

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
52 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: https://www....
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317 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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38 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 ...
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1answer
570 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 V1....
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1answer
177 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
31 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
276 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
81 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 top,...
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823 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 ...
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1answer
148 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 ...
4
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1answer
87 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
127 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 ...
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1answer
94 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 ...
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2answers
105 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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40 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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56 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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97 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
318 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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50 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 ...
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1answer
295 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 ...