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

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how to tell if i messed up my led strand [on hold]

Is there any really easy way to test my led strand? The leds in question are ...
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15 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 ...
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0answers
12 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 ...
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0answers
24 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 ...
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2answers
74 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. ...
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2answers
37 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 ...
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3answers
121 views

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

At first, I'm programmer and my electronics knowledge and soldering skills is pretty basic. I want to find a bright addressable (also called digital) RGB LED strip which can be attached to RPi and ...
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1answer
27 views

How to decide the amount of resistors for gpio

I will be using raspberry pi for connecting following sensors 1) DHT-11 Digital Temperature & Humidity Sensor for temperature and humidity measurement 2) HC-SR501 PYROELECTRIC INFRARED ...
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3answers
42 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 ...
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1answer
50 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 ...
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1answer
83 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 ...
3
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1answer
50 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. ...
2
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1answer
94 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 ...
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0answers
51 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
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1answer
76 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 ...
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1answer
784 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 ...
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2answers
74 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 ...
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1answer
75 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 ...
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0answers
159 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 ...
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1answer
72 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 ...
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0answers
45 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 ...
2
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1answer
251 views

Model B+ i2c issues with 7 segment display

I purchased a 4 digit 7 segment display from adafruit and got it working on my old model A running adafruit occidentalis operating system. I recently bought a model B+ and installed the latest version ...
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1answer
859 views

Why ACT led is blinking and raspberry not booting?

I have a Raspberry Pi (Model B) with a 8GB SD card, and Rasbpmc installed. Suddenly, one day, it not boot and have these symptoms: Red Led is ON Green Led (ACT) is blinking A rainbow screen is ...
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1answer
43 views

PiGlow LED went out

(The gist is in bold) I recently got a PiGlow and started playing around with it. When I have the yellow LEDs set at > 200 for an extended amount of time, one of them starts to flicker and ...
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0answers
125 views

getting the rasberry pi to controll a tm1802 led strip

Hi i recently purchased a tricolor led strip from radio shack and while they are made for the arduino I am very sure they will work with the raspberry pi. They take in serial data (24 bytes) and use ...
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1answer
226 views

ws2801 Wiring Problem?

I recently purchased a 5m long strip of ws2801 leds. I've been trying in vain to get them to light up. During part of my troubleshooting I decided to confirm that I was getting power across the strip ...
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1answer
78 views

Need help in my LED Switch REST API [closed]

I would like to seek help on my LED Switch REST API. I have created my own REST API and able to light up my LED when I type in the URL for example: localhost:3030/7/1 to light on and ...
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0answers
42 views

LED Printed Circuit for RPI

I have searched high and low for this but I have not been able to find anything close. Basically what I am looking for is a PCB which has a red and a green LED on it and already has the appropriate ...
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2answers
102 views

Error on displaying mySQL records in my REST API

I would like to seek help on my REST API. I have finished constructed my basic REST API for my Raspberry PI and able to work now, thanks to you guys. Now I would like to display mySQL database records ...
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0answers
128 views

controlling non addressable Led-strips using the SPI

For a project,I need to control RGB lightstrips by DMX and I want to use only 3(RGB) DMX channels.It seems logical to use non addressable lightstrips,for that seems to be the cheapest method (I need ...
0
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1answer
40 views

powering a RPI with its circuit from one wallsocket

I want to power a RaspberryPi with 54 LEDs (24 white, 24 warm white, 6 RGB - probably all at 20mA or something like that) from one wall socket. I'm planning to use the Pi to control the LEDs via ...
2
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2answers
103 views

Why does sudo not work in this case?

I was playing with the raspberry pi leds (How do I control the system LEDs using my software?) Interestingly, on my pi the following command fails: sudo echo heartbeat ...
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1answer
431 views

Can't PWM LED on pin 18

Using this code, I can't use PWM on the pi. It's modified off of a Linux user article. import time import RPi.GPIO as GPIO led = 18 GPIO.setmode(GPIO.BCM) GPIO.setup(led, GPIO.OUT) ...
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1answer
155 views

display LED Blink Count on I2C 16x2 LCD

I want to blink a LED and display its count on I2C 16x2 LCD. But LED is not glowing at all. I used https://www.adafruit.com/product/1115 which uses i2c . I connected LED with 270ohm resister between ...
0
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2answers
128 views

Red LED only staying on momentarily during bootup?

I have a red LED that I just want to light up using the GPIO pins on the Raspberry Pi. I got it to light up using the 5v pin. I tried it on a GPIO pin with a simple python script and it failed to ...
0
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1answer
56 views

Simple LED code says that object has no attribute output?

I installed RPi.GPIO .5.1 and my uber basic led code says that the object has no attribute 'output'. I am hooking up the 12 pin to the Breadboard and I have ground hooked up too. Here is my python ...
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0answers
21 views

Loop not halting

I am trying to make a LED blink on a Raspberry Pi, and have quite easily got it so that it will blink indefinitely. However now I am trying to make it so the LED stops blinking after a certain time. ...
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2answers
40 views

How to fix boot section / firmware and keep user files

My model b pi runs raspbian since half a year. The pi hosts an apache webserver, file server and other programs. A cron job is performing apt-get update / upgrade on a regular basic. The latest ...
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3answers
195 views

how to turn on and off an led with only a tactile button

I'm a beginner to the raspberry pi and python. I want the pi to act like a flip flop to the led so that when i push the button once, it will turn on and if I push it again, it will turn off and so ...
0
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2answers
56 views

Having a Cook server send signals to Pi [closed]

My idea is to have a Pi running and controlling some LED lights. I have a Python script that controls the LED lights. How does another computer (Windows based) send a signal to the Pi to switch the ...
0
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2answers
124 views

LED lights on pin 1 but it fails on other pins

Hi i am new to this raspberry pi. I am trying to light up LED it works fine on pin 1 with 3.3V. then I am trying to use pin7 and pin11 both but it fails to light. I already checked the GIPO setup for ...
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2answers
132 views

RF transmitter and multiple receivers to led on/off control

I would like to control multiple RF receivers to turn on/off LED. Can you please let me know is there any cheap generic RF transmitter and multiple receivers to achieve this using raspberry pi?
2
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1answer
922 views

Big LED matrix controlled by Raspberry Pi

It is possible to attach simple, monochrome Nokia Cell Phone display to rpi and it displays whole graphics to it. So is it possible to do the same with custom LED matrix (I mean like 41*15 or more ...
0
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1answer
83 views

I want to switch power for a led strip

I'm making an on call sign that can be activated via a web page. I'm not sure if this is even necessary. but i was thinking about using a relay or some other device to power up the strip when in use ...
0
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1answer
168 views

Using PI4J to toggle a led on a breadboard

Since yesterday I been trying to figure out how to turn on a led on and off, my problem is that Pi4J (from what I can see) only takes up to 20 GPIO inputs and my breadboard is set to 30 and from a to ...
3
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2answers
472 views

WS2801 LED's only glow white

FOUND THE PROBLEM: apparently my Raspberry is somehow broken because it does work on the raspberry from someone else... I bought the raspberry and a strand of ws2801 led pixels and I try to make them ...
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1answer
237 views

Setup a led that blinks via php server

I wanted to blink or just lit up an LED on my Pi GPIO pin via a server/website. I've the resources like Pi, LED, php server etc. I just don't know how to code to connect my Pi to server and control ...
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1answer
158 views

Pi stopped working by itself

I had some fun with the device, configured it as Wi-Fi router and it worked fine for a couple of months. Then hot-spot disappeared and only red LED is now on. I don't have a spare HDMI monitor or ...
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2answers
275 views

What GPIO pins are required to Power RPi? [duplicate]

We are using Raspberry Pi Model B: We used USB connector from PC - confirmed output - 5V, with 2 leads: Connected +5V to Pin 2 Connected GND to Pin 6 on connector - Inserted Ethernet cable ...
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2answers
71 views

How to bring out Status LEDs to be available on enclosure [closed]

We have developed a product based on Raspberry Pi and currently designing the enclosure. To enable users to understand the status of our device we would like to provide two LEDs. These LEDs would ...