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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.

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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
328 views

Using digital pin 11 for DMDCon and IR remote

I have a project where I would like to control a countdown clock using a remote with: Arduino Uno R3 Development Board Funduino Uno Protoshield Board Freetronics Dot Matrix Display Connector ...
0
votes
1answer
615 views

Could an `analogWrite` command and its variable output values be used to power multiple leds with same intensity? [duplicate]

I seem to be getting the right response on single LED but with multiple LEDS or a relay connected LED strip the voltage outputs seem to be insuffiecient. What kind of analogWrite values does an LED ...
2
votes
2answers
3k views

Implement Visible Light communication using Arduino

I want to implement a simple VLC based communication system using two Arduinos and send messages/data/files between two PCs. For that I have a simple transmitter circuit with an LED on Tx side and a ...
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 ...
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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 =...
0
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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
3answers
416 views

Why do the LEDs visibly flicker?

The aim of the project was to be able to show two "kinds" of LEDs in a 8x8 single color LED matrix. I used a MAX7219 chip to drive the LEDs using my Arduino UNO R3 as the driver (with the usual ...
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
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1answer
62 views

Switch controlled power saving esp8266

I'm trying to build a door sensor with the esp8266. I want it to be battery powered and use deepSleep for power saving. I'm going to use a normally closed reed switch between D0 (GPIO16) and RST. I ...
0
votes
1answer
406 views

Arduino Wire communication with MCP23008 GPIO pin expander to turn on an LED with a button press

I am using an Arduino Uno and an MCP23008 GPIO pin expander, I have a momentary button connected to GPIO 2 on the MCP23008 and an LED light connected to GPIO 1 on the MCP23008. What I want is for the ...
-1
votes
1answer
4k views

How to fix 12V RGB LED Strip connection to NodeMCU?

I am trying to hook 12V RGB Led Strip (LTROP SMD 5050 RGB LED Light Strip) to a NodeMCU unit. I know there are many different tutorials on this and I am very new to wiring and electric circuits. I ...
0
votes
1answer
161 views

Breaking out of a while loop using IR remote for neopixel

I've been piecing together various lighting effects. I am wanting to have each lighting effect loop until another button is pressed to trigger another lighting effect. I've come to a bit of ...
0
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2answers
157 views

Random LEDs light up on 10 MAX7219 modules

I'm trying to create an IoT clock using 10 MAX7219 (Serially Interfaced, 8-Digit, LED Display Drivers) modules. I've created the following code: //clock.ino #define MODULES_X 5 #define MODULES_Y 2 #...
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votes
1answer
102 views

How does Peggy2 drive rows with 74HC154 Decoder?

Trying to program Evil Mad Scientist's Peggy 2 board without their Library. The board drives a LED Matrix with Source 74HC154 Decoder Sink STP16CPSO5 LED Sink Driver Schematic What has me ...
0
votes
1answer
82 views

Turn on LEDS one after another

I am trying to turn on LEDs one after the other so that I can start at one end and slowly turn the LEDs until it reaches the middle of the strip. The code works coming from the end of the LED strip, ...
1
vote
1answer
41 views

LED and Switch Compolation Error Arduino 101

I'm getting an error on line 9 for some reason, (digitalWrite(Sender, HIGH);), and I just cant figure out why. My goal is to have two sets of flashing patterns, one for each switch state. I don't know ...
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 ...
0
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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 ...
6
votes
1answer
161 views

Working with multiplexers for constant voltage output

I'm working on creating a circuit where I'm trying to have the ability to switch multiple strands of LED rope on and off at a time using an Arduino and a multiplexer. With my current configuration, ...
3
votes
2answers
226 views

How can I connect nearly 450 LEDs to an arduino without drawing too much current?

The question seems simple, but there's more to it: I'm connecting 4 74HC595 shift-registers to an arduino pro micro. 28 of the 32 outputs will be used to control LED segments of numbers. Each segment ...
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
vote
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
2answers
118 views

Can we connect 4 4-digit 7 segment LED Displays to a single Arduino board?

Can we connect 4 4-digit 7 segment LED Displays to a single Arduino board ? Is it possible without another component in between ?
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 ...
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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 ...
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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 ...
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 ...
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0answers
7k views

How to read the received SMS from GSM and do actions accordingy?

Here I am using AT commands to receive SMS and I am trying to read the received message. I want to switch on the builtin LED of the Arduino board but I am not able to store the received message in a ...
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 ...
1
vote
3answers
748 views

ESP8266 blink sketch not blinking LED

After flashing the blink sketch to the ESP8266, I removed all the unnecessary wires from flashing - and my setup to try and run the sketch looks like this: Something to note about flashing - it would ...
0
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 ...
2
votes
1answer
6k views

How to get neopixel to fade colorwipe?

I'm trying to get a fade to happen when an LED turns on/off during the color wipe rather than just abruptly turning on/off. I'm not quite sure how to do this though. #include <Adafruit_NeoPixel.h&...
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 ...
1
vote
2answers
489 views

NodeMCU NeoPixel

I am attempting to control a single NeoPixel with a NodeMCU, but I'm not having any luck. Even just loading the default Adafruit NeoPixel library sketch yields unsuccessful results. I've tested the ...
-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 ...
0
votes
1answer
8k views

Integrating 2 push buttons to toggle the LED ON and OFF

Hey guys need your help in verifying out this program about toggling the LED ON and OFF using 2 push buttons.What i actually want is to let my LED stay ON when i press and even leave the push button-1 ...
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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 ...