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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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20 views

Controlling LED strip from GPIO Help?

I have a ws2811 LED strip that I was powering using an arduino, but I want to do some more complicated things with it, and figured my old raspberry pi would be perfect. So I followed a tutorial online ...
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13 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, ...
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3answers
68 views

Problem controlling LED on GPIO3

I need to add a status led to my pi zero w and after taking a look at the pin out I decided to put an led between pin 5 and 6. Please see attached picture. I soldered a blue 0805 SMD led directly on ...
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1answer
40 views

Risks of powering short LED strip directly from GPIO

I am trying to understand the simplest ways to power a short LED strip of 30 WS281x lights. Most of the instructions I’ve found mention using a separate power supply for the LED’s, but is it ...
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2answers
32 views

Turn on multiple output with single button

I'm working on project with single input multiple output logic. The project require two or more led controlled by single button (momentary). the steps are like these : 1. When the button pressed for ...
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2answers
38 views

turn led off after 5 seconds

i am new with RPi.. can someone help me, i am working on a RPi project. i am using lcd touch screen with guizero. i create 5 pushbuttons to turn on 5 different led. BUT i cant turn off the LED after ...
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12 views

Long wire leading to bad display of led matrix?

I am using a 16x32 RGB led matrix by Adafruit. When I tested it at my desk with short 6 inch jumper wires it worked just as I wanted. However, for my actual project the screen cannot by right next to ...
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1answer
46 views

How Can I Make Lights Flash On My Raspberry Pi When A SSH Connection is Active?

I recently got a Raspberry Pi B+, and I have been playing around with it a lot. I want to start a personal project where, when I link to my Pi through an SSH connection from my laptop, I can make a "...
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1answer
39 views

Are my resistor leds safe

I have the following leds ... ... that I hope to be able to connect to my pi for power and disk activity indicators. I read some guide that claimed that around 330Ω resistors were needed, but the ...
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3answers
60 views

Powering 100mA LED

I want to power an 1.5V LED fully and control it using pi. I can only use 16mA per pin and i need 100mA. Can you give me suggestions? I can turn it on with 5V and 35 ohm resistor but not control it. ...
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0answers
22 views

Problems with music sensitive LED strip project

We want to install a music-sensitive light system using four or five LED-strips. We have several ideas but no experience with this topic. Following plan: You connect your phone with the Raspberry ...
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1answer
25 views

Pi Camera LED blinking

I have gotten back to using my Model B Revision 2.0 Pi. After starting it up, I noticed the red LED on the camera is blinking (not the Pi itself, that one is solid). When I take a picture, the ...
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2answers
59 views

Tinkering with environment variables

i want to run my pi headless, and only wire up some switches via gpio to operate it. i want it to monitor 3 switches, and tell if theyre high or low, and react accordingly. it should be launched every ...
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1answer
40 views

Power indication

I have build a musicbox with an rpi 3+ and added a power button and 2 buttons to turn the volume up and down. The buttons have LED lighting, I have connected them to GPIO pins but this results in ...
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1answer
33 views

LED matrix won't light up properly

As you can see it won't light up correctly, why is it so? Is it possible that there are some issues with common cathode or anode? I tried using just that smaller one by itself, in a similar fashion ...
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0answers
28 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 ...
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2answers
92 views

How to control 12V LED with the GPIO?

Heyo! How to control single 12V LED using Raspberry's GPIO? To be more exact, I need to connect 12V LED & push button to Raspberry Pi 3 B+ GPIO in order to control LED (on/off) and read button ...
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1answer
51 views

anode RGB LED to raspberry Pi

I have wired up a common anode rgb led to my raspberry Pi. I dont understand why its not lighting up. My setup is this: 5v to rgb anode rgb to pi pins ( 5,6,26) My code is const Gpio = require('...
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1answer
1k views

Why do LED lights need resistors? [duplicate]

Can someone explain why LED lights need resistors when connecting to pi. The raspberry Pi is either providing 3.3v or 5v depending on if it's connected to power pins or gpio pins. Your set up would ...
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0answers
50 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 ...
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0answers
105 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 ...
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1answer
23 views

Need RPi3b voice control

I'm failing to find a simple way to control my RPi via microphone. I've fount some projects but they all require things such as Google AIY voice kit. Is there any simple way for me to control GPIO ...
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0answers
24 views

Control WS2812 without arduino just raspberrypi

Is it possible to control a LED strip WS2812/b without needing an arduino in between and using the Glediator software? If so, how? All i managed so far is lighting up all LEDs by connecting 5V and ...
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2answers
64 views

Why is my code not working between time hours?And what should be done if im using PIR sensor ,what is the change that should be done in this code [closed]

import RPi.GPIO as GPIO import time GPIO.setwarnings(False) GPIO.setmode(GPIO.BOARD) GPIO.setup(3,GPIO.OUT) #Define pin 3 as an output pin while True: if(time.hour(18)&&time.hour(5)) #...
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0answers
82 views

Raspberry Pi 3 won't boot, red LED light only

I was using my RPi for testing the sensors of my project, when suddenly it stopped and won't boot after that. I did not touch anything nor destroyed parts of the pi. The sd card is working fine as it ...
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1answer
17 views

Writing two different hex values to linked shift registers

I'm new to raspberry pi and electronics, and I'm working on improving my first (meaning my design, no tutorials) project. My original project was two seven-segment displays linked to two shift ...
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1answer
65 views

Neopixel lights do not change color

I recently bought a 1 meter WS2812B strip. I installed the Adafruit Neopixel Circuit python library with the following commands: sudo pip3 install --upgrade setuptools pip3 install RPI.GPIO pip3 ...
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1answer
52 views

Unplug ethernet seems to freeze connectivity-check script

I'm working on a raspberry project with a RPi B+, running Debian stretch. I've included a LED which should turn on when the Pi establishes an internet connection, and should turn off when this ...
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1answer
131 views

3 PWM pins for RGB LED

I got an RGB LED, one mass and one for blue, red, green. So I got a list there are only two PWM compatible pins listed. Pin 32(GPIO 12) and pin 33(GPIO 13). But for my RBG LED I need three pins with ...
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2answers
138 views

How did I manage to fry my pi 3+B? Can I recover it?

I'm new to Raspberry pi and electronics in general. All worked fine (a node webserver, reading a DHT22 sensor) then I tried this tutorial - https://www.raspberrypi.org/magpi/breadboard-tutorial/. It ...
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0answers
89 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 ...
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0answers
32 views

RP 3b - green led flashes 4 times [duplicate]

I tested one SD card on 2 different RPis and I get the same pattern: no boot, green led blinks continuously on a 4-blink pattern. This would point to a problem with the SD card but I tried reading the ...
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1answer
39 views

Powering common anode project from GPIO output instead of 3.3V

Instead of doing PWM on each "return pin" as it can be seen in Schematic diagram A, my idea is to use only one PWM for powering the circuit from GPIO4 (PWM) as it is drawn in circuit B. Is it (diagram ...
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1answer
35 views

My Raspberry Pi B+ has the Ri 2 B pinmap

I trying out different java programs for my RPi B+ V1.2 and as far I have only tried to blink with a lamp for a few seconds. It works. Now I want to try to blink with a lamp by using a button. In ...
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1answer
292 views

LED pwm fading is flickering

This is how I'm fading some LEDs using a logarithmic function. But with that the LEDs are flickering somehow. I don't understand why... import time import math import RPi.GPIO as GPIO GPIO.setmode(...
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2answers
598 views

Red led repeatedly blinks 4 short and 4 long on RPi 3B+ with TinyCore

The red led repeatedly blinks 4 long 4 short and the Pi doesn't boot. Tested with various power adapters. When powered up without an SD card the red led is solid. I'm using an SD card that works fine ...
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2answers
685 views

How to properly implement threading within a function toggled by a button [closed]

I need a little help if possible. I'm trying to make a threaded function which will make my LEDs blink randomly as long as the button is pushed. when it is released it should exit the function and ...
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1answer
88 views

GPIO Pins Stay Active

On my Raspberry Pi B+ I have a standard program to blink a LED. I run it using the terminal command python blinky.py, and when I do, the LED lights up, but does not blink, as it should. I then cancel ...
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2answers
243 views

IR LED range and angle

So my goal is to operate my TCL Roku TV with my Raspi. I'm using these LEDs: AIRSUNNY three Legs 5 pairs Infrared Diode LED IR Emission and Receiver and my setup is pretty much identical to this: ...
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2answers
226 views

Can't blink a LED using SPI interface on Raspberry Pi v3

As a part of my PoC project, I'm using single 5050 LED made by Adafruit. I wired it like this (LED - RPi): DI (Data Input) - SPI0 MOSI CI (Clock Input) - SPI0 SCLK GND (Ground) - GND VCC (5V) - 5V ...
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0answers
73 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....
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2answers
40 views

Raspberry Pi Zero W not responding

I bought it about a year ago and a few days ago I plugged it into my Mac with a micro USB. I did make the mistake of plugging into the USB port initially but it did respond. For a while it worked i:e ...
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0answers
41 views

RasberryPi Zero W LED does not turn ON

I am new to Rasberry Pi and trying to turn on an LED . I am using PIN BCM 18 as output and using a Python code to run it. Tried both methods using GPIO and gpiozero. But do not see any output. I have ...
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0answers
32 views

How to fix my Raspberry Pi 3 b1.2 - No red or green LED?

I went to start it up one day and it will not start up. There are no red or green LEDs. The power cord works but the Pi does not work. Please help me.
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0answers
67 views

How to generate a hardware PWM wave for driving an LED through RPIO?

I've looked through the documentation of RPIO, and used GPIO18 to get my PWM up and running. This is my code: from RPIO import PWM servo = PWM.Servo() servo.set_servo(18, 4000) As explained in the ...
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1answer
551 views

IR LED attachments on the RPi NoIR v2

So I bought parts I didn't know would not fit together. Namely, the Pi NoIR v2 Camera, and IR LED module(s). I figured those two combined would be somewhat like the other 5mp IR Cameras on Amazon. It ...
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0answers
22 views

LED Strip causing Pi to reboot

I am in the process of setting up a LED strip to use with Hyperion. The strip is 5M of APA102 30LED. I have it connected to the proper 3 pins on my Rpi3 and powered by an external 5V 12A PSU. ...
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2answers
78 views

Controlling 12 RGB LEDs (with adjustable colour mix), with long cable runs

I need some advise on this -- driving 12 RGB leds individually. I was thinking of this model: LL-509RGBC2E-006. If I use these "plain" RGB LEDs with 4 pins, so that would mean I need to set 12 x 3 = ...
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2answers
835 views

RPi stopped booting, only red LED, different rpi/sd/power supply do not work

Problem: I have a working sd card, a working rpi, and working power supply. When I then plug in an ethernet cable into the rpi and reconnect the power supply to a power bar (where I have 3 other rpi's ...
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2answers
372 views

Noise in the GPIO when output is high or low

I just set up my pi to run Homebridge allowing it to control an LED strip over GPIO pins, it all works well except the LED lights flicker with radio interference. This interference is very noticeable ...