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Questions tagged [led]

A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices.

A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices, like mobile phones or micro-controller boards.

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Android: Keep camera-LED on after screen turns off

since i'm at the beginning with Android coding i hesitated to post my question, but now i'm at the point where i can't resist. I have a service which turns on the camera-LED onCreate: @Override public void onCreate() { // make sure we don't…
stefanjunker
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Firebase notification LED blink

I'm using Cordova to make a mobile app and I'm trying to send a push notification via google's Firebase. I was able to set title, body, badge, sound, etc. but I can't figure out how to set a LED blinking when receiving a notification. I tried using…
Nicolas
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Android - Camera flash light blinking in wrong intervals in different devices

I am developing an app, in which I want to blink the flash light in specific interval. Below are the steps I have followed. 1) Set the Timer for specific interval. 2) In run() method i did the code for TurnOn and TurnOff flash. But the interval of…
Mitesh Shah
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C# way to convert char into 8x8 binary

Can you help me look for a way to convert char into 8x8 binary (am not sure how to call it) like for example an "A" 00011000 00100100 00100100 01000010 01111110 10000001 10000001 10000001 am actually doing this manually :( suggestions are still…
jaysonragasa
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How to use JAVA to control LED light connecting to PC via USB/SerialPort/etc.? What device should I use?

I would like to write a program in JAVA which can control LED lights connecting to "something" that is connected to the computer. JAVA program will consist of 8 toggle buttons in JFrame. The buttons are numbered from 1 to 8, and when the button with…
Northnroro
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How to LEDs of a USB keyboard under Windows

I'm trying to set the keyboard LEDs of a USB keyboard. I already tried / know the following: To set PS/2 keyboard LEDs you can use the CreateFile("\\.\Keybd", GENERIC_WRITE, 0, 0, OPEN_EXISTING, 0, 0); DeviceIoControl(hKeybd,…
martin
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Check if notification LED exists on device and which colors are available

I've implemented red LED light for my notifications for test purposes, but... Do I have to check if the device has LED (in case that device doesn't have this feature) and if so how to do it? Also, are LED colors predetermined? I tried to find some…
Munez NS
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Blinking an LED with an Arduino and pySerial

I feel really silly for asking this, but I've been shocked at my inability to find the simplest example I can imagine for talking to an Arduino over Serial. I have a connection set up, and I understand how to write both Arduino Code and Python, but…
Slater Victoroff
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Raspberry Pi + neopixel: If brightness of RGB LEDs are reduced, does that mean certain colors cannot be rendered?

Referring to the python library neopixel (rpi_ws281x), to control WS2812B RGB LED strips, does trimming the brightness by scaling the byte for each sub-LED in a pixel from 255 to 127 limits us from rendering certain colors? According to the…
siva
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Does anyone know how to modify/disable the blinking power LED when OS enter into sleep mode?

Does anyone know how to modify/disable the blinking power LED when OS enter into sleep mode? Or is it feasible to do this by using OS? Does the power LED only controlled by hardware? Or OS could modify it? Thanks,
Fengwei Zhang
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Controling Android's front led light

I'm trying to implement a 1 second red blinking at the front led whenever the user presses a certain button. But I'm having trouble finding documentation, tutorials or even code-examples on how to access and work with the front led (by that I mean…
joseph
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No LED light for notification Android

no matter what I tried but there is no notification light. I'm running Android 26 Oreo. My phone only displays blink light for messages and missed calls. String CHANNEL_ID = "my_channel_01"; NotificationManager nm = (NotificationManager)…
T D Nguyen
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Includegraphics problems with a PNG

I have problems to insert an image into my .tex file. This is the code: \begin{figure} \includegraphics[width=1\textwidth]{Blockdiagram} \caption{Diagram} \label{figure:BlockDiagram} \end{figure} It says that it cannot find the file! The same…
legami
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Arduino (processing) Library in Netbeans and control

I am trying to control 4 LEDs and getting analog input from 4 contacts. The program is written in java, so to gain acces to the functions of arduino, such as AnalogRead() and setting an LED to high or low, would importing the processing library let…
Casper Marcussen
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Send long array to arduino over serial from processing

So i build an 24x16 (hight of 16, length of 24) LED matrix and am using an Arduino Uno to control it. It is only a one color matrix and i am using an array to store all of the bits of data. This is an example of how i am storing the data on the…
user3399652
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