Questions tagged [led]

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

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LED only works when plugged in backwards

My LED only works when it's plugged in "backwards" like the following example: https://pi4j.com/1.2/images/gpio-control-example.png My understanding is that the longer pin on the LED should go ...
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38 views

Dimming a 0-10v dimmable light

I've raspberry pi 4 and I'm building a project that simulate sunrise and sundown. I've found that LED - WYZM HBL-100W that get 220AC AND DC 10V, I can dim it by lower or increase DC voltage level. ...
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74 views

How to wire a button

O have tried to do this so many times, so many websites, so many books, and it just won't work. I do not know how to wire it so that the LED lights up when I press the button. I'm pretty sure that I ...
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2answers
76 views

Is it possible to power IR light module from 3.3v GPIO

Welcome, i've got a question that is bugging me for quite some time lately. I've got RaspberryPi zeroW with ZeroCam camera module (without IR filter). To get it to work in dark I bought IR LED ...
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1answer
64 views

Piezo Buzzer Driven By Rpi GPIO Problem

I'm trying to light up an LED and play a buzzer noise at the same time. Here is my code so far: Import RPi.GPIO as GPIO Import time GPIO.setmode(GPIO.BCM) GPIO.setup(7, GPIO.OUT) while True: ...
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2answers
145 views

AC mains dimmer dimming 7W LED lamp problem (RpiZero + MPDM V4.1)

I'm trying to dim a 7W LED with a Raspberry Pi Zero for home automation. However it doesn't work as expected. I followed this tutorial : https://www.youtube.com/watch?v=wqY4-gHqvZI . I have the exact ...
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1answer
52 views

PIGPIO problem with delay on scripts

I am trying to run an old Raspberry Pi 2011.12 as a server to control a RGB LED strip. To this I am using PIGPIO since this is the best solution (RPi.GPIO is software based, which creates flickering). ...
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1answer
45 views

Why the same GPIO pin is not working anymore?

I was working with a very simple code: import RPi.GPIO as GPIO GPIO.setmode(GPIO.BCM) GPIO.setup(24,GPIO.OUT) GPIO.output(24,GPIO.HIGH) But after running one time when I am running the code nect time ...
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2answers
169 views

Is there any built in LED connected with GPIO pin?

In Arduino a built in LED is attached with number 13 Digital pin. Is there any LED like Arduino in Raspberry Pi,which I can use to test my code?
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1answer
44 views

How to power on multiple LED through 3.3V rail ? (Power supply problem)

I'm trying to use the 3.3V rail to power up 10 LED (20mA/LED). I read that the raspberryPi could supply until 1A through this 3.3V rail, that's a lot more than needed when all the LEDs are powered on....
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1answer
78 views

12V Solenoid with Relay doesnt trigger

So I am using 8 AA 1.5V batteries that is wired to my 12V 16 channel relay which is wired to my Rpi. I want to be able to control 16 solenoids and use the relay as a switch for the solenoids. As far ...
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1answer
42 views

Turn on a Led with Raspberry Pi

I found this video on YouTube, and I want to try doing the same, the problem is that I dont know how much voltage the GPIO18 has. Link of the video: https://www.youtube.com/watch?v=86x6NweQsdY I've ...
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2answers
64 views

Slight dip on the GPIO 5v line when LEDs are on

I have my raspberry pi set up to do two main things: control 16 LEDs via 16 transistors each connected to an out pin. The LEDs are collectively fed the 5V from the GPIO. power a chip also on the 5V ...
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1answer
67 views

RPI 3B+ 'activity' LED always flashes approximately every 1.5 secs With Buster booted external USB SSD?

Booting my pi 3B+ from Buster on a USB SSD 240G Kingston A400, I now get quick pulsing yellow (green?) activity LED flash bursts, every 1.5 to 2 seconds, during normal operation, even when only the ...
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1answer
73 views

Massive old LED Sign…powered by Raspberry Pi?

I got this massive 165cm/16kg LED sign: https://www.alpha-american.com/p-alpha-premiere-9200c.html and it seems to be working as far as I can tell when I power it up: https://youtu.be/Msf971cHOQs . ...
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1answer
39 views

Whole control the green led on RPI 3B+

I would like to learn gpio control on raspberry pi, and now I have a RPI 3B+ I found that the greed led is GPIO29 I think it will work to set the green led on or off by gpio, but at the same time, ...
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2answers
118 views

Can I drive a custom LED matrix from my Pi

I have an idea for a project, but I am unsure of the best route to take. I am going to create a custom 11x10 LED matrix (addressable LEDs like WS2812) with the intention of lighting up certain LEDs ...
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1answer
36 views

Led on before declaring it

Hello I need some help with my leds, I have 2 leds one green and one red. What I want to do is just turn on the green led (and turn off the red) when I press a push button, that is to say all the time ...
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0answers
21 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) ...
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196 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 ...
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1answer
42 views

RPI project Minecraft Server

me and a project partner are running a Minecraft server off of a RPI and connecting via its wireless feature. we wanted to create a python script which would control an LED and toggle it on/off based ...
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22 views

Raspberry pi 3 LED vertical panel display problem

Is it possible to change the resolution of my raspberry pi 3 to 224x756?? I have a vertical LED panel (224 x 756) and the display of my rpi don't fit the screen. My interface for my panel is HDMI. ...
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26 views

Screen Resolution for raspberry pi 3 LED Screens

Is it possible to change the resolution of my raspberry pi 3 to 224x756?? I have a vertical LED panel (224 x 756) and the display of my rpi don't fit the screen. Help thanks!
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1answer
54 views

Raspberry Pi and car led ground effects

I am about to add led strips to my car. I will have at least 4 zones to start out and might add more. 1. Under carriage 2. Front end 3. External 4. Internal Doing it now, I will have 4 controllers ...
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2answers
47 views

What's wrong with my current calculation for an LED panel?

I am trying to understand how much current is required for one LED matrix panel, however, I don't quite understand it in general. Take this panel as an example. This is an 64x32 LED matrix, and its ...
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2answers
944 views

Power LED from 3.3V Power Pin without Resistor

I tried wiring one white LED to the 3.3V pin on a Pi Zero W with a 330 Ohm resistor but it's not as bright as I would like. If I wire it up without a resister I get a good amount of brightness. Is ...
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0answers
84 views

GPIO LED is constantly on. GPIOZero can't turn it off

If power is supplied to the Pi then the LED will be on by default. I've got the LED connected to GPIO pins [4, 6] and the script can not turn it off. I've switch the cables around and that's resulted ...
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0answers
94 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-...
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1answer
43 views

Connecting jumpercable to gpio pins

My teacher gave me a large group of jumper cables attached to one another. this might be a stupid question but if it's attached like on the on the bottom picture what is the order of the cables? (...
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1answer
122 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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0answers
119 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
145 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
137 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
63 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
148 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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15 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
67 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
45 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
83 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
42 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
44 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
198 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
47 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
43 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
150 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
890 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
107 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
94 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
255 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 ...