Questions tagged [led]
An LED is a type of light source which is typically fairly small and has low power requirements.
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Using Excel to communicate to an Arduino to light 20 LEDs
I want to show progress on a wall using LEDs from data added in an Excel speed sheet.
I want to have about 20 different LEDs maybe more. Can this be done with an Arduino Uno?
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2
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LED will fade in but not fade out
The brightness of the LED gets higher normally but when it gets to full brightness it just stays like that - it doesn't dim. Sorry if this has already been answered I just can't seem to find anything ...
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1
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strip.clear() is not clearing/turning off the NeoPixel strip after resetting the ESP8266
In the code below which is running on a WEMOS D1 (ESP8266), a NeoPixel strip turns on 1 LED in red which moves left to right and then right to left whilst the board attempts to connect to Wi-Fi in the ...
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Same LED but different brightness on same PIN
I connected a led to pin 7 (with a small resistance to avoid burning it) and tried the code below, with and without pinMode as output
void setup() {
pinMode(7, OUTPUT);
Serial.begin(9600);
}
void ...
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1
answer
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Make two LEDs fade in and out with with different PWM values
I have two UV leds, one Vf 3.3V @ 150 mA and the second one Vf 5V @ 150 mA. I need a circuit to make them fade in and out alternatively, i.e., as one goes dimmer the other goes brighter and vice versa....
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2
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Just one more pin!
I have an Arduino project to control a motor's speed at 3 levels, indicated by 3 LEDs, so level 1 is speed 1 and LED 1, and so on for levels 2/3.
Also, I added a low-battery voltage indicator to ...
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1
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L LED on Arduino is constantly on and com is not detected
When I connect the Arduino to the computer, the L LED is constantly on and com is not detected. However, when I press the reset button, the L LED starts blinking for about 10 seconds and com appears. ...
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blink a Grove - RGB LED Stick
I am trying to blink a Grove - RGB LED Stick (10 - WS2813 Mini 3535) with this code:
#include "FastLED.h"
int ledState = LOW; // ledState used to set the LED
long previousMillis = 0; ...
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0
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How to use a DF Mini Player Busy Pin to start an LED Sequence?
I'm using a DF Mini Player with my Arduino Uno project I keep getting stuck on the same point - how to trigger my LED sequence. I discovered, through some google searching, that utilizing the BUSY ...
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Does the UNO R4 still have the standard on-board led on pin 13?
I need to add support for the UNO R4 (both models) for a library I'm maintaining. The library uses the LED on pin 13 as status indicator. I can't find any information whether that LED is still there ...
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2
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Push button issues
I have been using https://wokwi.com/ to learn Arduino and I am having a problem that seems to be happening no matter what I do. I am trying to set up a push button and an LED. The end goal here is to ...
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2
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How to turn LEDs based on voltage readings?
I am trying to turn LEDs in an LED bridge based on the voltage reading from a power source. when the Voltage is zero nothing is ON and then the LEDs gradually turn ON as increase the voltage connected ...
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LED doesn't completely turn off with digitalWrite(led, LOW);
When I was testing out a program I found a strange behavior of ESP8266.
LEDs don't turn off completely in the first digitalWrite(led, LOW), just the brightness of the LED goes down, but it does turn ...
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ESP8266 seems to be killing a while loop
When i was testing out a program I found a strange behavior of esp8266
It seems to get out of a while loop even when there's no option of getting out on code
I don't know if these are related but here'...
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Why does a simple LED Blink not work using mbed.h PWM and Arduino Nano BLE?
I have set up a very simple test program to blink an builtin LED using PWM. Following the mbed example and setting the period to 4 seconds (0.25 Hz) and duty cycle to 0.5, the expected behaviour is ...
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How do I turn on 3 LEDs in a repetitive sequence where all three LEDs would then turn OFF when the push button used is released?
Basically, how do I modify my code listed below to turn ON each of the three LEDs one at a time in a repetitive sequence while keeping the push-button pressed?
Red (3 sec),
Yellow (1 sec), and
Green (...
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1
answer
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Transmitting voice via VLC
The project I'm working on: Short-Range Coded Visible Light Communication System.
Visible Light Communication (VLC) systems use light to transfer data between transmitter and receiver over short-range ...
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1
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fastLED help - special reinforcements needed
Hello help needed trying to get fastLED to start and stop at specific points on the strip, i have this nice fade animation but need to split the strip intov about 3 sections and have it run at ...
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Why can't my four batteries (6V) can't power this circuit while usb 5v from arduino can?
I have this circuit
And I want it to power all the led rgb (100 in total), I want to make a independent portable circuit, so I don't have to use the usb power. The thing is when I use this circuit it ...
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RGB LED randomized colors and LDR fading at the same time
Im trying too make an RGB LED that keeps changing color's randomly, and makes the brightness fade at the same time with an LDR, yet I keep getting an error that says too many arguments to functions.
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Problems using HC-SR04 with LED displays
I'm having problems using an HC-SR04 ultrasonic sensor in conjunction with an LED display module. The sensor appears to work fine when outputting values to the serial monitor, measuring distances up ...
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I don't understand what's wrong with this code [closed]
int ledy = 5 ;
int leds = 4 ;
int ledk = 3;
int button = 2 ;
int count = 0 ;
void setup()
{
pinMode(ledy, OUTPUT);
pinMode(leds, OUTPUT);
pinMode(ledk, OUTPUT);
pinMode(button,INPUT);
...
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ESP32 PWM with extended resolution doesn't work as expected
I have attached an RGB-LED to three output lines of the ESP32 and I'm trying to fade all colors independently. Since it didn't work with my code, I went back to the basic ESP32 ledcWrite_RGB sample ...
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3
answers
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Interrupt on button press + debouncing
I want to have an interrupt function executed whenever a button is pressed.
The button is connected to pin 2 and the GND. Therefore, the pin is turned to LOW whenever the button is pressed. In ...
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1
answer
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LEDs controlled by PHONE on ESP32
I am having doubts with a project I'm making.
My project involves a sets of LEDs stripes, among which some are controlled from a smartphone, and some automated. The LED strips are connected to an ...
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2
answers
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PWM with a TRANSISTOR on flexible LED filament
I would like to create a custom lighting, with PWM capability, powered from battery. I would like to use flexible led filaments, and since those consumes more than 40mA, I can't use them directly on a ...
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1
vote
1
answer
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Fading out a led with reed switch loop
I was hoping to get some help on the fading led which I am working on.
For my project I need to have a led, which when it is placed next to a magnet, continuously shines, but as soon as it is taken ...
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1
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Simple FastLED sketch that crashes when led strip is long but not when its shorter
I have a pretty simple sketch that crashes, and crashes hard (Platform.io console says "Disconnected (read failed: [Errno 6] Device not configured)" and I need to power off/on the Arduino to ...
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3
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Cannot read LED state
I am running into a problem on a very basic functionality.
I want to read the state of an LED.
I have confirmed that under the specified circumstances, the LED receives 1.9V.
I try to read its state ...
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1
answer
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Function call only works if called once
I have 3 LED chains which are all mapped to concentric rings. Each ring has a its own 2D array with the chain number & LED number. I have a function that is passed a ring array and then lights the ...
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2
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Strange problems driving an Optocoupler (PC123) with a Nano
I'm having some strange issues getting a Nano to drive a PC123 optocoupler properly.
What I'm trying to do: In the real world, I need to press a button ONCE, and have the device that I'm connecting ...
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2
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1
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One LED in 4x4 matrix does not turn on [closed]
I'm an art student and absolute beginner to electronics/code - my broader goal is to learn how to control individual LEDs when there are many of them (like 64 or more even, so am learning about ...
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1
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Blink LED without delay with stepper motor
Based on a previous question I modified the script to use blink without delay.
Unfortunately, it does not work, any idea why?
I am using SparkFun RedBoard Plus, Qwiic LED Stick - APA102C, Adafruit ...
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1
answer
225
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Stepper motor and blink LED
I connected a LED stick to a stepper motor. Is it possible to blink the LED without stopping the motor rotation?
I am using SparkFun RedBoard Plus, Qwiic LED Stick - APA102C, Adafruit Stepper motor - ...
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1
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L LED keeps staying on
I am trying to get the Arduino to reboot my PC when it is off.
Using the front panel header on the PC, I connected the power switch and PLED directly to the Arduino Uno as the header only outputs 5 V.
...
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1
answer
270
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LED blink patterns with multiple LEDs with millis() not using Delay()
I want to make LED blink patterns with multiple LEDs with the millis() function. I researched about it but did not find a perfect solution.
I found one blog, but it is using a LED pin number array; I ...
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1
answer
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Does an 5V 2.1 A will fit for this Led Schema?
Hello I would like to create an Arduino protoype with Led WS2182B.
I currently have
Arduino NANO (not UNO, like in this schema)
65 Led WS2182B = Which gives me 3.9 Amp of suply for full brighness (65*...
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1
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How to turn led lights off and on in order when below a certain photovalue?
I'm making a traffic light simulation with a photoresistor but it's not working properly.
When the photovalue drops below a certain point ( a car comes by) a peeping sound should play for a second and ...
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1
answer
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Apparently the photoresistors don't pass the input at the leds
I am making a school project where i need to create a parking loot in tinkercad. Me and my mate tried to use a bunch of photoresistor that worked as a sensor. No light = car = red led; light = no car =...
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FastLED changing colour at holding state
Basically make a code to guide users through a box breathing exercise (breath in for 4 seconds, hold for 4, release for 4, hold again for 4, repeat) to help relax them.
Right now my code is running ...
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1
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Powering LEDs with Arduino uno 5v
I'm working on the sound reactive led lamp as my first project and have slightly different materials to start with. First I'd like to simply learn to power the LED strip.
from https://www.youtube.com/...
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How do I keep one function continued until a variable is completed?
The code's purpose is to change from one led to another if the LDR detects a certain level of light for a given time. Currently, since I cannot wait 5 minutes to complete one circuit, each LED should ...
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LED brightness variations
I'm using two different types of code and noticing that in the first set up the last LED is dimmer than the rest. Then in the second set up, the first LED is brighter than the rest. I would like to ...
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How arduino PORTB pins are addressed if I want to access them with pointer?
So Let say I want to access Digital Pin 13. Thats port B pin. Is there an memory address associated with this pin 13 of Arduino Uno r3?
How Port B pins are addressed with corresponding pin numbers ...
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Can't figure out why what I'm trying to do isn't working. Trying to light up a RGB with buttons with AnalogWrite
DISCLAIMER : I have just started Arduino, like 2 days ago, I've been following some tutorials on YouTube, and I tried to do this myself, but I can't figure out why it isn't working, can't find what I'...
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2
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Toggle button switches through case statements with button debouncing
The overview of my code is that I want a toggle button to be pushed and each button push will move the code to the next case statement. In each case statement, there will be different LED functions. I ...
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Trying to keep my main code running unless an input is LOW for a certain amount of time
I have code that creates a sequential signal with 4 LEDS. It cascades to the right. This works when I hold down the input button. What I need help with is having the code run exactly the same when ...
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How exactly do Bicycle LEDs work? (Arduino Project)
Table of contents:
What I want to achieve
Problem I'm facing
What I've tried
Possible Hypotheses
What I want to achieve
Hi guys, I’m working on a DIY LED Light project to install on my bicycle, ...
Genki
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Are resistors necessary for 8x8 LED matrix?
I was following the official tutorial of LED matrix integration and couldn't figure out why there is no resistor.
I assumed there are built-in resistors in the LED matrix, so I did an experiment by ...
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2
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Why does the official tutorial for LED matrix scanning writes column pin twice?
I was following the official tutorial and confused by the source code.
Arduino Official built-in example: RowColumnScanning
// when the row is HIGH and the col is LOW,
// the LED where they meet turns ...
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