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Questions tagged [led]

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

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LED strip PWM on GPIO18 + mono audio output

On the RPi 3 I would like to control a WS2811 LED strip with PWM (GPIO18) by keeping the audio working. It looks like for the RPi Zero (I'm unsure for RPI 3 though) left and right channels of the ...
myoan's user avatar
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2 votes
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How can I get my python program that uses the requests library to run on boot via the crontab

I am working on creating a python script to retrieve data from a server using the requests library, and then display it on an adafruit led matrix using a raspberry pi. I have a program that functions ...
ho88it's user avatar
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2 votes
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264 views

Malfunctioning Raspberry pi 4, red and green led on all the time

My Raspberry Pi 4 won't boot anymore, there is no picture on the monitor, and both LEDS (red, green) are on all the time, they do not blink. I formatted the SD card with SD Card Formatter and ...
user2715315's user avatar
2 votes
0 answers
67 views

How do I power an IR LED signal that is 50 feet away?

I'm building an IR blaster with an LED that will be wired 50 feet away from the circuit. I'm going to use this 18 gauge wire to extend the LED connection. I'm using a GPIO pin connected to a BC547b ...
Michael Khalili's user avatar
2 votes
0 answers
487 views

Need help with Controlling WS2812B LEDS

I have made a 5 x 5 WS2812B RGB LED matrix to work with my raspberry pi. I'm trying to figure out how to run several tests from this tutorial: https://tutorials-raspberrypi.com/connect-control-...
Juriaan 's user avatar
2 votes
2 answers
463 views

Issue running LED matrix with Fadecandy controllers in Processing

I have built an LED matrix using 2048 ws2812b leds. It is being controlled with 4 fadecandies and a processing sketch. I have it running fine on my laptop, but when I try to run the same sketch on ...
Drc3p0's user avatar
  • 21
2 votes
1 answer
466 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 ...
kot's user avatar
  • 121
2 votes
0 answers
177 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 ...
monojohnny's user avatar
2 votes
0 answers
434 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 ...
Rogue's user avatar
  • 121
2 votes
1 answer
2k views

controlling rgb led strip via spi and node js

I recently purchased a pi and a string of individually addressable rgb led lights from shenhzen kapata (actually amazon, but they're the ones who sell it) and I'm trying to control it with my ...
richbai90's user avatar
  • 121
2 votes
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Unable to control 5V LED strips

Using this addressable LED strip: WS2801 Led Full Color character string matrix screen point source 12mm 5V WS2801 IC Chip, Addressable Color, need for controller. Identify IC every led light, Red- ...
puk's user avatar
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1 vote
1 answer
66 views

raspberry pi red solid gren blink once

I have a Raspberry Pi 4 8GB everytime when I power green light blinks once and the red solid light is on. I connected to the HDMI screen and there is no output on the screen. I tried restoring the ...
Mubashir's user avatar
1 vote
1 answer
86 views

Using MAX7219 Dot Matrix module with Luma.Led on different GPIOs

I have a MAX7219 dot matrix module (this one) that I'm trying to run on my Raspberry Pi 4 with the Luma.LED library. Its documentation suggests the following GPIOs/pins be used: Board Pin Name ...
Vroni's user avatar
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1 vote
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RPi 3B not booting, only a stable red light

As I said in the title, my RPi 3B just wont boot and has a stable red light. I have tried the following: Re-flashing using balena etcher and raspberry pi OS flasher Using multiple different power ...
ExploitedPizza's user avatar
1 vote
0 answers
111 views

Problems addressing WS2812B LED Strip with Raspberry Pi 3 A+

Hello! I am currently having issues addressing my WS2812B LED-strip correctly with my RPi 3 A+. I have followed the following video guide: https://forum.core-electronics.com.au/t/problems-addresing-...
Mads Rasmussen's user avatar
1 vote
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33 views

I2C 1 light at a time`

i am currently using the NCP5623 (I2C LED Driver) to light up my 5V 1A (as written on the box) RGB LED strip. i followed the sample connection as shown on the datasheet of the NCP5623 and when i ran ...
seonghwife's user avatar
1 vote
0 answers
96 views

Rasberry Pi 4 LED.off() will not turn led off in a function

I have a simple circuit connected to my Raspberry Pi 4 with 3 push buttons and an LED. The buttons are connected to gpio2(pin 3), gpio17(pin 11), and gpio16(pin36), with the LED connected to gpio25(...
tcolbert's user avatar
1 vote
0 answers
257 views

How to use Rpi SPI MCP3008 ADC to read visual light LED's transmit and receive signals?

EDIT: Firstly I wrote it a bit confusing way. So let me summarize my problem. This is something like answer to comment bellow. (1) I am trying to make somethin like visible light communication based ...
dejv_IT's user avatar
  • 11
1 vote
0 answers
176 views

WS2812B individual addressable lights too slow

I have an rpi-0-w that I use to control WS2812B strip (300 LEDs). With one strip everything is fine, but when I connect 2 more strips, obviously, update speed drops. Is there a way to increase the ...
Nauris Grinbergs's user avatar
1 vote
0 answers
156 views

NeoPixel library slow with large number of WS2812B LEDs (Raspi3)

Noob here, I am currently working with a 10m long strip of 144LED/m density LEDs. The problem is with such a high number of LEDs loops (like a color wipe for example or filling LEDs one after another) ...
lakadibo's user avatar
1 vote
0 answers
140 views

How would I go about writing a program(python) to mimic the use of an AND Gate using Raspberry Pi

How I set up my breadboard: Placed SN74LS08N (AND gate) on a breadboard. Connected IC pin 7 to GND and IC pin 14 to 5 V for IC to get powered. Connected GPIO pin 16 to IC pin 13, Connected GPIO pin ...
Vnix7's user avatar
  • 11
1 vote
0 answers
70 views

LED Strip on Raspberry Pi Check if its On - Neopixel

How can I check if the one pixel is on or not? Is there any function for that. I've googled but couldn't find anything helpful. import board import neopixel pixels = neopixel.NeoPixel(board.D18, 17) ...
Shalomi90's user avatar
  • 121
1 vote
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2k views

A PWM object already exists for this GPIO channel

I have a bit of a dilemma. I am currently using BCM GPIO 14, 15 and 18 to control an RGB status LED using PWM. I have configured my raspberry pi 3 to pull down pin 14 (red) on boot, to indicate the ...
George Lazu's user avatar
1 vote
0 answers
454 views

How to get maximum GPIO output speed in Kernel module?

I'm writing a Linux kernel module on RPi2 to push an array to RGB Led matrix, so I want to have maximum speed of GPIO to reduce the 'flick' when it run Bit Angle Modulation. According to this site, ...
msshhp's user avatar
  • 11
1 vote
0 answers
637 views

GPIO in /sys/class/leds/

I am doing a project with Raspberry Pi and OpenWrt. I need to attach indicator LEDs. Basically, I need to modify the DTS for bcm2710 and add additional GPIOs in the led section such that it gets ...
jayanta525's user avatar
1 vote
0 answers
189 views

Raspberry Pi 3 B+ LED Light Blink not working

I am trying to get my LED to blink once, but it is not working. I connected the brown wire to pin 6 (Ground), and the red to pin 7 (GPIO 4). I watched a tutorial on connecting the circuit but it is ...
Andy Lebowitz's user avatar
1 vote
0 answers
499 views

MAX7219 7-segment via SPI not working

I am following these instructions to get a simple 7-segment display working: https://github.com/rm-hull/luma.led_matrix My problem is that as soon as one of the 3 SPI Pins are connected the digits ...
clamp's user avatar
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1 vote
0 answers
804 views

Ethernet Indicator led on pi 3B+ not glowing

I am a newbie to Raspberry Pi and recently bought Raspberry pi 3 B+. I first downloaded and burn the minibian on sd card as some course suggested minibian. But whenever I connect pi with power, only ...
K_lash96's user avatar
1 vote
0 answers
317 views

Cannot lighten up 12V LED strip with Raspberry pi 3

Bought a 12V 5M RGB LED Strip a 12V 5A power supply 6 IRLZ44N mosfets. i am trying to light up the led strip with PiGPIO. followed the https://dordnung.de/raspberrypi-ledstrip/ tutorial. and the led ...
KiarashRzg's user avatar
1 vote
0 answers
768 views

Red camera LED fails to turn off

I am using Raspbian 4.9.35-v7+ (3B+) and the camera: https://www.adafruit.com/product/1567. This may be flagged as a duplicate to previous questions under similar titles; however, none of their ...
Jacob A's user avatar
  • 111
1 vote
0 answers
690 views

Hardware setup for LED with external power supply

I am looking for help to use a raspberry pi 3 as a multiple LED switcher. The setup should be: 6 LEDs at 3W, 9.6V and 300mA (each!) a external power supply for the LEDs a breadboard to put everything ...
Chrizzldi's user avatar
  • 111
1 vote
0 answers
200 views

WiringPi can only turn on 8 LEDs

On my RPi 3 I have a PHP website to control 10 LEDs. Each is wired to a separate GPIO pin and 220 ohm resistor. Here is the code: <html> <head> <title>LED Control</title>...
Yubin Lee's user avatar
  • 121
1 vote
0 answers
25 views

Lighting Issue On Snapshots

I'm creating a proof of concept project for my Pi 3. The concept is to take a photo using a USB webcam when a button is pressed. That part was simple using OpenCV. However, the lighting is fairly ...
Apexdev's user avatar
  • 11
1 vote
1 answer
357 views

Button isn't triggering in python script

Software guy here, first time doing hardware. Here is my breadboard setup (yellow is GPIO-8, green is ground): Here is my Python: import RPi.GPIO as GPIO from time import sleep GPIO.setmode(GPIO....
M Leonard's user avatar
  • 125
1 vote
0 answers
2k views

How can I get my raspberry pi 3 to work with SK6812 LEDs without a screen?

I have a raspberry pi 3 and am trying to get it to run the SK6812 LEDs with no screen. When I have my ASUS monitor connected, the LEDs work fine, and when I disconnect the screen and reboot, the LEDs ...
GC2000's user avatar
  • 11
1 vote
1 answer
588 views

Can I control 5050 RGB Strips with the Raspberry pi?

I have purchased 5 meters of a 5050 RGB Strip yesterday. I bought it for my PC case, but of course I don't want to use 5 meters in my case. I want to do some smart lighting in my room and a bias ...
Noah Krasser's user avatar
1 vote
0 answers
139 views

After power on Rpi3 RED led steady but green continuously blinking. what could be the problem?

i brought new Rpi3 and boot 16gb card with 2017-03-02-raspbian-jessie when power on red led steady and green blinking is there any problem in booting process of pi? HDMI not showing anything neither ...
SagarH's user avatar
  • 11
1 vote
0 answers
361 views

Problem with SoftPwm from Microsoft.IoT.Devices.Pwm

I'm new here, started working with RPI and Windows Core month ago. Currently I'am trying to control RGB Led Strip ( set light, turn on/off, dim) from RPI. To achieve this I use RPI 2 model B V1.1, ...
Daniil T.'s user avatar
  • 111
1 vote
0 answers
47 views

House switches light the RPI led strip

I'm having an issue with my LPD8806 led strip. My RPI and led strip are both located inside a lamp, both being powered by a multi output source (not the best one). Before this I was powering the led ...
Sorin Grecu's user avatar
1 vote
0 answers
2k 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 ...
Charles P.'s user avatar
1 vote
0 answers
319 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 ...
sliver001's user avatar
1 vote
0 answers
210 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 ...
onemach's user avatar
  • 111
1 vote
0 answers
435 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 ...
Eligoo's user avatar
  • 11
1 vote
0 answers
246 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 ...
knilssen's user avatar
1 vote
0 answers
327 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 ...
Christian's user avatar
  • 111
1 vote
0 answers
59 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 ...
lucs100's user avatar
  • 123
1 vote
0 answers
450 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 ...
MonkeyTravel's user avatar
1 vote
0 answers
483 views

controlling 12 V RGB LED strip with raspberry pi

We are trying to control a RGB led strip with a 12 V power supply. The servoblaster does not work. Can you please suggest some other software we can use?
navi's user avatar
  • 11
0 votes
2 answers
56 views

make white 3.3 Vforward led ON exactly when output pin is high; output pin goes through level shifter then motor driver op amp

COMPONENTS; raspberry pi; level shifter 3V in 5V out; motor driver (H bridge L293D chip = op amp with diodes to protect inductive kick on power off); solenoid valve; CIRCUIT; GPIO23 on raspi is an ...
William Garber's user avatar
0 votes
0 answers
46 views

w2812b led strip flashing except when touching data line

I'm working on a led script with a w2812b strip and a pizero. I have a cap on between the data and ground and a resistor on the data line. When I run the script the strip flashes seemingly randomly, ...
pizzadog's user avatar