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

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Beginner Question - Reading Temperature, Opening Water Valve, Status LED

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 ...
3
votes
1answer
61 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
50 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
39 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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39 views

Trouble connecting Pi to Digital LEDs (_spi_module not found)

I have cut a strip of 4 LEDs from these digital addressable LEDs: https://learn.adafruit.com/digital-led-strip?view=all I have a 5V / 2A power supply (the one recommended) from Adafruit, with a 2.1mm ...
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56 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
46 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
32 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 ...
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138 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
381 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
36 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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90 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
136 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
66 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
39 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
91 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
91 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 ...
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1answer
32 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 ...
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2answers
86 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
192 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
117 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 ...
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2answers
121 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 ...
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1answer
43 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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18 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
34 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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129 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 ...
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2answers
48 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 ...
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2answers
118 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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105 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?
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votes
1answer
618 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
votes
1answer
72 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 ...
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1answer
132 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 ...
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337 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
159 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
118 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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224 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 ...
0
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1answer
219 views

Pi4J - Changing GPIOs from and to Input, Low and High

I am trying to create something which uses Charlieplexing, and to use it, I need to be able to turn GPIO Pins to and from different states (Low, High and Input) from what I understand from this video: ...
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2answers
108 views

My first breadboard / led

I loosely followed this. I've been studying breadboards for about an hour now, so this is super fresh in my head. My understanding is as follows: 5v power on the +(red) track (white wire) Ground ...
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2answers
124 views

L.E.D controlled by IF STATEMENT from variable

I want to control some L.E.D's through the GPIO ports depending on the value of "variable1" which will become a raw input. The problem is, if variable1==70 then both led 12 and 16 with light, but only ...
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1answer
159 views

How can I control the PWM via the sysfs

I want to set the PWM for some tests with a tricolored LED. I want to be able to set it up via the sysfs interfaces but I'm having a very hard time finding any information on how to do this. What is ...
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votes
3answers
808 views

How to use 2 x MCP23017?

I need to control 32 L.E.D's individually, now looking through the forum, the common solution is to use MCP23017 chips, as they can control 16 l.e.d's. With that in mind, I would require two chips. ...
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147 views

multiple PWM for led control

I'm creating a musical instrument based on capacitive sensors and I want to add some color to it. I would like to use PWM controlled LEDs because I want to make them dim and fade away nicelly. My ...
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3answers
246 views

Control 18 LEDs individually? (17 GPIO pins)

Note: I have read Controlling many LEDs with few GPIO pins, but I can't buy additional parts (Degree project) The end result is to make a noughts and crosses grid with 2 LEDs per grid cell. This ...
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338 views

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- ...
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6answers
2k views

Using one Raspi to control long (>100ft) of 5V LED strip

I am using the below LED strip for accent lighting 5M WS2801 Blcak PCB 32LED 5050 RGB Digital LED Strip Individually Addressable 5V item: nonwaterproof black pcb ws2801 led strips Model: 5050RGB ...
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2answers
140 views

LED strip has R-G-B instead of DI and CI

I went and bought an LED strip which has the following labels +V R G B How does this correspond to another naming scheme I have seen which looks like so: GND DI CI +5V I could use this ...
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2answers
183 views

How do I get simple lighting inside a case for my Raspberry Pi?

I'm new to the RPi. I'm looking to put a light inside my RPi case for a glow effect. But since I'm not an electronics guy, I have no idea what kind of an LED I can use and where to put it inside the ...
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1answer
78 views

Network does not work anymore

My Raspberry ran for about a year and was a webserver and samba server. Suddenly I couldn't connect to the raspberry pi and ping also didnt work anymore. I flashed a new OS to the sd card but I still ...
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1answer
2k views

Controlling Multiple analog RGB 12V led strips

I need to control several (5 to 10) analog RGB strips which have a separate power supply at 12V or 24V. Just like this one for example. I need to control the intensity of each colour channel for each ...