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

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45 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
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2answers
66 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 ...
1
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0answers
24 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
103 views

Why are some GPIO pins HIGH when the Raspbeery Pi boots up

I have an easy circuit wired up, with a 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 ...
1
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0answers
32 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 ...
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1answer
38 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
38 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 ...
2
votes
1answer
365 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 ...
0
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2answers
68 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
58 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
150 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
votes
1answer
68 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 ...
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0answers
33 views

can I program gpio led light to flash on particular website?

I have used python to create a program that lights up the led through GPIO on the rasberry pi. I was wondering if and how I could write a python code so that the led light would light up only when I ...
0
votes
1answer
46 views

Pi is not working properly red led not glowing and green led blinking

I bought raspberry pi b+ some days ago. It worked properly for some days, but now I face a problem the red LED is not glowing and green LED is blinking along with processor is overheated. Can any one ...
0
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0answers
69 views

Using LED strips (many!) and mutiple power sources wiring up the ground?

So I'm using LPD8806 leds with RasPi, and we are using many many lights and need multiple power sources. With one power source, we wired the negative of the power source to a ground pin on the Pi. ...
0
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4answers
332 views

How to blink LEDs on/off continually, while continuing execution of a script?

I've connected red and green leds via GPIO and I can successfully switch them on/off using RPi.GPIO - now I'd like to: start an led blinking on/off every 1 second have the script continue its ...
2
votes
3answers
324 views

How to connect 7-segment 4-digits display with Pi?

I would like to connect such a 7-segment 4-digits display (with common anode) to the Raspberry Pi: What's the simplest way to do it with Python for example? Do I need the RPi.GPIO package? Is there ...
0
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0answers
63 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?
0
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0answers
85 views

Led connected to pin is always on

I've been following basic tutorials on how to programmatically turn on leds from my Raspberry Pi 2. I'm using a breadboard, and I connect 3 leds, using a male-female jumper from the pins of the ...
0
votes
1answer
78 views

having problem with GPIO switch

I have been working on a project that will allow me to take picture using a switch. So for that purpose i setup the GPIO and all necesseary tools for that code, Python-dev and etc. When i run the ...
1
vote
1answer
139 views

Raspberry Pi to sync lights to audio input from PC

So I'm wondering if it's possible to make the Raspberry Pi sync lights to sound coming from my PC. I would use an usb soundcard for a sound input and a usual audio cable. Right now I'm running ...
1
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2answers
187 views

Raspberry Pi 2 - Model B - no boot with Raspbmc

I was trying my brand new Raspberry Pi 2 Model B. I've used the Raspbmc installer to "burn" the image on my micro sd. After I've connected the raspberry to the ac adapter and then to the TV, nothing ...
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1answer
89 views

TLC5947 with a Raspberry Pi

I have been trying to get 8 RGB leds to work with a TLC5947 driver using a Raspberry Pi. But I am not able to get the leds to work. I have tried with the help of fpulse from Wrobbel. But this did not ...
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1answer
112 views

problem with LED matrix setup with raspberry pi model B+

I have a raspberry pi model B+ , and an 8x8 LED matrix(single colored) , so I connected 8 GPIO pins to the 8 row pins of the matrix and another 8 GPIO pins to the 8 colomn pins. Note that I am pretty ...
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1answer
98 views

extend the current for PWM LED Control

i am using the raspberrypi to have 2 led's fade up and off. My script works and its ready to go. But i need to get my LED's brighter. Is there a way to extend the GPIO Current of the rasperry pi ? ...
2
votes
2answers
150 views

Powering several LEDs from GPIO output

I'm currently working on a "rotating cube" project where a raspberry pi will be used to determine which cube face is at the top and any given time using an accelerometer and light it up with LEDs. ...
1
vote
1answer
85 views

Question about Breadboard positioning

That's my current structure: The short metal of the LED (-) is connected to GND, and the longer (+) is in the port 26. This black "thing" (I don't know the name) is connected to my Pi B+ by a gray ...
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2answers
132 views

Raspberry not booting w/ older Raspbian Release (only Red LED)

I've been trying to install one of the Raspbian Images on this Site: http://downloads.raspberrypi.org/raspbian/images/ So far none of them have worked. I've tried multiple SD Cards and used different ...
0
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0answers
275 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 ...
0
votes
1answer
46 views

Switching led over gpio

I would like to switch led over GPIO command. I follow this tutorial: https://projects.drogon.net/raspberry-pi/gpio-examples/tux-crossing/gpio-examples-1-a-single-led/ and I have few problems. Here is ...
0
votes
1answer
67 views

controlling a ws2801 led strand

So for a project that I am working on in my free time, I want to create a spectrum analyzer with a raspberry pi which then lights up an led strand according to the music. I have the code working just ...
1
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0answers
32 views

External FDX and LNK LEDs

I'm making a project where the Raspberry Pi will be mounted inside a closed box, with buttons and LEDs on the front panel. Is it possible to have panel-mounted LEDs that replicate the status of the ...
0
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0answers
70 views

Hardware for Hyperion

I'm planning to build an ambient lamp, and I like the features that the hyperion has. First, I was going to get these LED's: (WS2801) Addressable Color 12mm Diffused Digital RGB LED Pixels Lights ...
1
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2answers
191 views

Why are blue LED's glowing brighter than green and yellow LEDs? [closed]

When I connect a blue LED complete with a 1K ohm resistor to pin 17 and turn it on, it gives out a somewhat bright, satisfying light. When I do the same with a green LED, the led light is very dull. ...
1
vote
2answers
99 views

I'm looking for a serial input type “polychromatic” LED as an output for my raspberry pi. Does such a device exist?

Forgive any potential neologisms, but I would like to acquire a light that can, say, display 64-256 different shades of color based off of a digital numerical input signal? It can be a usb light, but ...
4
votes
3answers
2k views

Which addressable RGB LED strips are beginner friendly and Raspberry Pi friendly?

I'm programmer and my electronics knowledge and soldering skills are pretty basic. I want to find a bright, addressable (a.k.a. digital) RGB LED strip which can be attached to RPi and programmed ...
1
vote
1answer
80 views

How to decide the amount of resistors for gpio

I will be using raspberry pi for connecting following sensors DHT-11 Digital Temperature & Humidity Sensor for temperature and humidity measurement HC-SR501 PYROELECTRIC INFRARED PIR MOTION ...
0
votes
3answers
141 views

Power LED is very dim on RPi B+

if I am plugging in the power supply the red power led lights very dim. I found several guides to test the the board with a multimeter but these were for the other revisions, and it seems like B+ is ...
2
votes
3answers
115 views

Driving LED stripes as non-root user

I am using python and the Bibliopixel library (https://github.com/ManiacalLabs/BiblioPixel) to drive a strip of LEDs (type LDP8806). For some reasons, I wanne be able to use this w/o using superuser ...
2
votes
1answer
580 views

Want to run a simple C program on startup of pi

Im new to linux and the pi . Im stuck with this situation where Iv been trying to run a simple LED blinking C code as a test , so that it will be executed during startup Code works fine when its ...
4
votes
1answer
131 views

Troubleshoot MCP23017 and LEDs

Anyone have any tips to help troubleshoot turning a simple LED on connected through the MCP23017? I've installed i2c-tools, and smbus. Nothing in my blacklist.conf Added i2c-dev to /etc/modules. ...
3
votes
1answer
461 views

Is my Pi's GPIO damaged?

I am trying to test GPIO output on a Raspberry Pi, and I am wondering if it is broken. These setups work: 3v3 >> +LED terminal -LED terminal >> resistor >> GND (the LED is unusually dim here) 3v3 ...
0
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0answers
107 views

RGB LEDs control over Web

I want to control my RGB Leds via Browser and pi-blaster. But I am helpless as a programmer. So I installed node.js and pi-blaster and the pi-blaster.js extension in node.js I made an HTML page with a ...
2
votes
1answer
106 views

Beginner Question - Reading Temperature, Opening Water Valve, Status LED [closed]

I am completely new to Raspberry Pi and would like to hear your input on this project that I need to solve. My question is: What hardware do I need, how would I connect it and how would I solve the ...
7
votes
1answer
11k views

What do the LEDs on the B+ mean

Not a duplicate of this rPi.SE question, as I'll explain in a moment. GPIO.RPI_REVISION returns 3. As far as I can tell, looking at my B+, there are no LEDs labeled: OK, FDX, LNK or 10M. There are ...
1
vote
2answers
100 views

Resistor calulation for two LED

I want to connect two IR LED to the 3.3v output on the PI in series. I need to reduce the 3.3v to 3.0v. What kind and measure should my resistor be? I swear this is not a word problem from ...
0
votes
1answer
143 views

Rasp PI spectrum analyzer led strip length

I'm new to raspberry-pi and electronics. I was looking to this tutorial: https://learn.adafruit.com/raspberry-pi-spectrum-analyzer-display-on-rgb-led-strip/page-1 Is it possible to build that ...
2
votes
0answers
216 views

PWM-based controlling an LED-strip using transistors, circuitry problems [closed]

I know there are some similar questions out there, but I'm really new to electronics and unfortunately they didn't provide me help. I want to control a tricolor LED strip (being able to dim each of ...
1
vote
2answers
121 views

Turning LED light on with Pi

I am looking to build a home security camera with a LED light attachment. Many people mention they use a IR Illuminator for the light source which often seem to be DC 12V. I am not sure how one would ...
0
votes
0answers
63 views

PWM to control brightness on i2c LED backpack?

I have something similar to this, it works, but it's too bright! I am aware that LED brightness can be controlled by pulse width modulation, but I don't know if I can safely do that with an LED ...