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Questions tagged [led]

An LED is a type of light source which is typically fairly small and has low power requirements.

0
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3answers
60 views

Do I need a pull-up/down resistor for button LED circuit?

When reading up on how to make a circuit that turns an LED on when a button is held down, I keep finding people saying a pull up or down resistor must be involved, to avoid the flickering state of the ...
0
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0answers
29 views

What's the required voltage for ws2815?

I am working on ws2815 led strip with the esp8266 on arduino 1.6.6 fast led library.Using CD40109B level shifter to convert 3.3V of esp output to 12V .It's working fine upto 31 leds according to the ...
0
votes
1answer
24 views

Assign and control Digital pin from String

Here is modified version of Blink example #define D8 13 String p = "D8"; // the setup function runs once when you press reset or power the board void setup() { // initialize digital pin ...
0
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1answer
54 views

74HC595 shift register not working

I got my Arduino kit a few days ago and I've been going through some of the tutorials. I got to the 8 LEDs with a shift register tutorial, where I got stuck. Nothing would light up after I plugged ...
0
votes
1answer
23 views

What are the purposes of the different LED lights on a Arduino UNO board?

The LEDs namely L, TX and RX on the board. Furthermore, whenever the board is connected, the L LED blinks to the frequency of the delay that I set. [Eg: delay(1000);] If I miss any other LED, do ...
0
votes
1answer
26 views

20 m LED WS2811 Pixel Stripe 12 V

i need some help for my masterthesis. I plan an Light and Sound installation and for this I decided to use the shape of an Dodecahedron and I want to put LED RGB Pixel Stripes on the surfaces to light ...
0
votes
2answers
47 views

Methodology for designing/prototyping LED patterns

Several of my projects go through this time-consuming and tedious phase: design a LED pattern for a geometry of WS2812 LEDs implement it with e.g. FastLED write to Arduino and see results goto step 1 ...
0
votes
1answer
61 views

Arduino button-controlled LED with AVR Assembly

I am trying to make a simple button-controlled LED, but I cannot seem to get any input from the button that would change the state of the LED. In other words, the program keeps branching to lighton, ...
1
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0answers
58 views

LED strip with 12v power connected to ESP32

I'm looking at controlling a ws2811 strip and I have seen mention that you should share the same ground between the strip and the controller, which does make sense. I do not currently have a proper ...
2
votes
1answer
94 views

LED intensity on digital pins [duplicate]

I am using an Arduino UNO. On any digital/analog pin, if an LED (with resistor) is connected and we use digitalWrite(pin,HIGH) the LED lights up rather dimly. On the other hand, if we use pinMode(...
0
votes
1answer
49 views

Controlling LED and Button with single pin

I am trying to use an ATTINY85/Ardunio Uno to turn an LED on and listen to a button input. I don't mind if the LED turns on when the button is used. I am have found this thread from a couple of ...
1
vote
1answer
34 views

Sanity check for dual IR LED circuit [closed]

If the intent is to drive the two LED's with 200-400mA (using PWM @ 38Hz), is there anything wrong with this solution? Perhaps this is a better solution, as it ensures the current is exactly the same ...
0
votes
1answer
33 views

Reading analog value while generating PWM signal

I'm trying to generate dim two LED strips simultaneously by generating two PWM signals based on potentionmeter value. The pot sets how bright each of the LED strips will be. To drive this I'm using ...
0
votes
2answers
59 views

could not convert 'digitalWrite(8u, 1u)' from 'void' to 'bool'

I am trying to make some LED lights to turn on when i flick a switch on my RC crontroller. I will connect the signal wire from RC controller to pin 8. The plan is: if i flick the swich, the LED's (pin ...
-1
votes
0answers
22 views

Using different data-outputs for SW2812 programmable LED

I am planning on building a DIY light chandelier (of sort). The build will be four circles of different sizes within eachother. The inner circle has a diameter of 30cm and the other 3 has another 30 ...
-2
votes
2answers
67 views

Turn on Indicator LED if Moisture Sensor Value >= MaxDryness for longer than 20 min

Hi so I am making a self watering flower pot with a moisture sensor and a peristaltic pump, the code is as follows: I want to add an indicator LED which turns on if the sensor value has been equal to ...
0
votes
1answer
55 views

How to fix this code so instead of having to hold button to change led, you can press?

const int buttonPin = 1; // the pin number of the pushbutton input pin const int ledPins[] = {2, 3, 4, 5, 10, 11, 12, 13}; // variables will change: int buttonState = 0; // variable for reading the ...
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votes
1answer
80 views

Problem with interrupts

Alright. This is what I wanted to do: Make a circuit and code the arduino such that there are 2 tactile switches, each with a predefined pwm value. Whenever any one button is pressed the led should ...
1
vote
3answers
65 views

Detecting pulsed LED

I am trying to use an Uno to detect if an LED is on or not. Sounds simple, but I am tearing my hair out on this one, here is why.... This is a model railway application and I want to detect an LED ...
0
votes
1answer
35 views

Help with simple gradually brighter flickering led

im a newcomer for arduino and sorry for any grammar error. So what im trying to do is replicating a flickering effect found on spacecraft thruster when they about to take off where the fire bursting ...
0
votes
1answer
46 views

Serial monitor doesn't work with piezo buzzer

So I can't see the distance of the proximity sensor anymore as soon as I type the code for the piezo buzzer. I've tried many things but it doesn't work.. Can anybody help me fixing this? int trigPin =...
-1
votes
1answer
145 views

ESP32 Dimmable LED Panel with MOSFET [closed]

I want to use ESP32 to control and use a dimmer for 6 LED panels in my bedroom. The specification of each panel is mentioned in the diagram. Although in the diagram it shows ONLY 1 MOSFET and 1 LED ...
-1
votes
1answer
35 views

How do I know if my Arduino is connected to my LEDs?

I have an Arduino Uno and a string of WS2811 LEDs. I am still trying to get started on this project, which is creating a Stranger Things wall. I've installed FastLED and uploaded the sample program "...
1
vote
2answers
235 views

Connecting 12V WS2811 RGB LEDs to Arduino Uno & 5V Power Source (Breadboard needed?)

I have an Arduino Uno, 12V WS2811 RGB LEDs (from Mokungit), a 5V power source, and DC power connector. I do not have a breadboard and hope I don't need one. This is almost exactly what I need to ...
0
votes
1answer
49 views

How to regulate a led on-board? [closed]

There is blink project consisting 3 sections: 1 - regulation of the led brightness using a potentiometer 2 - whenever: the button is pressed - the led is on - the button is released - the led is ...
1
vote
1answer
71 views

5 switches, 5 leds, 5 tones, in an Array

The idea is when a switch is pushed, the corresponding tone will be played as well as lighting up the corresponding LED. I have the circuit set up to where each array matches another, for example ...
1
vote
0answers
188 views

FastLED fill_rainbow - Unexpected red pixel

I'm using FastLEDs builtin fill_rainbow function for generating a rainbow spectrum on an LED strip. The issue is, I get a random red pixel midway through the yellow region. I've tried it on 3 ...
-1
votes
1answer
99 views

Dimming multiple leds with pot meter [closed]

I'm working on a small project. I have 13 leds which need to be controlled individually (turn on or turn off); Since I don't have 13 pwm pins I used a potentiometer to change the brightness. This ...
1
vote
0answers
22 views

TLC5917 SPI Speeds

I am attempting to use 3 x TLC5917 chips to drive a row of LEDs in PWM. The LEDs share a common anode being powered through a transistor, with each LEDs cathode going to pins on the TLC5917 Chips. ...
0
votes
4answers
69 views

help with a loop

I recently got into programing and I'm making an alarm. I cant figure out how to make a buzzer loop. I have two blinking LED's and two fading ones. Now I plan to have sound and it won't work. It only ...
1
vote
2answers
93 views

How can you have two blinking leds and a fading one

I am trying to make a alarm and I have two blinking leds (red and blue). They work fine but I want two more that fade in and out. I have a buzzer on it too. I am very new to programming. By the way, ...
2
votes
2answers
56 views

Using two sensors with delay concurrently

I want to use an ultra-sonic sensor and the led concurrently. I want the led to blink every 0.2 seconds and the ultra-sonic to measure distance without regard to the blinking. The problem is I have ...
1
vote
1answer
142 views

Midi controlled LED by USB [closed]

I am trying to create something that will allow me to control an individually adressable LED strip using an electric piano using its midi output. Some things to note: The piano can output midi ...
-1
votes
1answer
34 views

Adjustable temperature [closed]

How can I make a project where I can adjust a temperature with buttons and a display and if the temperature is higher than that I set, a led turn on ?
1
vote
1answer
65 views

Arduino UNO LED half brightness when connected to digital GND but not analog [closed]

I am using an Arduino UNO. When lighting an LED with the switch button on a joystick module, I have two situations: If the LED's cathode is connected to GND on the digital pin side of the Uno, the ...
-1
votes
1answer
87 views

how to connect 100 Leds and Blink them on Arduino [closed]

I am planning to connect 100 LEDs to an arduino in a parallel circuit. The current limit exceed beyond the Arduino UNO board. In want to blink all 100 LEDs at same time. So how can I provide power ...
0
votes
1answer
34 views

LED on Arduino does not blink

I successful installed arduino, added me to uucp and lock and loaded cdc_acm module. I use Arduino Uno R3, so I also installed arduino-avr-core. I have Arduino on /dev/ttyUSB0. I configured with: ...
0
votes
1answer
678 views

FastLED - How to Control specific LEDs

I am fearly new to Arduino and FastLED. I found a nice Sketch which fits almost perfectly to my needs. Just one Problem: I dont want the Sketch to effect ALL LEDs in one color. I want some LEDs in ...
1
vote
1answer
70 views

Blynk app, DotStar bluetooth control code help

This is my setup: Arduino Mega; HM-10 bluetooth module (bought off ebay, so not sure if genuine but works); Adafruit Dotstar addressable LED strip; iOS Blynk app; Hardware-wise, everything is ...
1
vote
1answer
67 views

Flickering LED when servo moves

I just got to play around with Arduino lately so I'm really new on this stuff and sorry for the grammar error. I got a work where I need to turn the LED on all the time, my plan is to add a slow fade ...
1
vote
1answer
35 views

Arduino with 8 LEDs and a switch

I have an assignment wherein we have 8 LEDs connected to an Arduino Uno which has a switch. These LEDs light up according to the johnson counter but every time I turn the switch off it should reset ...
1
vote
2answers
86 views

arduino firmware

Hi I was wondering if there is any way to/ how I might go about solving the following. I am designing my own arduino board based on a mega32u4 chip and I want my arduino board to light up an ...
0
votes
1answer
32 views

Use IR remote with arduino

I would like to use the IR remote with Arduino to turn on a LED and turn off the same LED when I push on the remote. That is to say : If I push on 1 I would like the LED turn on If I push on 2 I ...
0
votes
1answer
48 views

What value of resistance to put between the output of a 74hc595 and the LEDs?

I'm going to start a project to make an array of LEDs using the shift registers 74HC595, I've seen many tutorials and it's not really difficult using the Arduino plataform. The situation is as ...
0
votes
1answer
140 views

Looking to blink entire led strip

I am fairly new to FASTLED programming and am looking to make my entire LED strip blink at the same time. Similar to the Example Sketch "Blink" however all 30 of my LEDS. I might just be having a ...
0
votes
0answers
39 views

RGB LED colour transitions with accelerometer

I try to convert an accelerometer's upper hemisphere x and y rotations - meaning clamping output only to z positive orientations - into two pre-defined colour transitions of an RGB LED, where x and y ...
2
votes
2answers
385 views

How do I change the default LED pin for displaying uploading

I made a board for my project based on Arduino Pro Mini. The problem is, that I had to put the LED on pin 4 instead of pin 13. What setting do I have to change to make pin 4 the default one? Or do I ...
1
vote
2answers
54 views

Keeping track of multiple actions

I have a number of LED's connected to an Arduino which receives a JSON dict. The JSON dict determines which action the LED's follow (either a fade, a pulse, on, or off), but I'm having trouble ...
0
votes
1answer
36 views

How to stop extra LEDs from lighting in LED cube

So I build LED cubes and the way I have it programmed is I use an analog pin for the ground layers and set them to high when i want an led on that layer lit up. So lets say I wanted the following LEDs ...
1
vote
0answers
59 views

Do I need one N3904 for each LED?

I want to control 4 (or more) LEDs using the PWM output pins of my Arduino. Here is how I have it on a breadboard, and it's working for me. Question: Is this schematic inefficient? Are there any ...