Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [led]

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

0
votes
1answer
11 views

Problem with SPI when using rf24 NRF24L01 transceiver with LED matrix MD_MAX72xx

I am currently using Arduino Mega to use a LED matrix and a NRF24L01 transceiver. for LED matrix, I use MD_MAX72xx library. While for the transceiver I use the RF24 library. I am already able to ...
-2
votes
0answers
27 views

Best way to make LED strip WIFI enabled [on hold]

I'm creating an addressable LED strip setup. However, I want it to be WiFi enabled and controllable through my iPhone. I've been looking at options such as ESP8266 to make this possible. My question ...
2
votes
5answers
7k views

Smooth breathing led

I am trying to make a simple breathing led circuit in which the intensity of the led varies between 0 and 255. I followed the Fade tutorial on the Arduino site, which gives me what I want, but I ...
1
vote
2answers
350 views

KY-022 IR receiver, LED always on, no output

I've been trying to use a KY-022 to read IR signals. However no output is being produced and the LED on the board is constantly on. Board: Arduino Uno R3 I followed the procedure found here. The ...
-2
votes
1answer
40 views

Data type problem

I have a program I would like to ask:   I use the Bluetooth control LED to light up. In the picture, the serial port window shows r, but the LED does not light up. What went wrong? Ask everyone, thank ...
0
votes
1answer
32 views

Component with controllable resistance from Arduino? [closed]

I'm new to Arduino and building circuits, and was wondering if there is a type of component, or some other way to do the following task: I want to control the resistance of a circuit from my computer ...
3
votes
3answers
24k views

Powering up LED strip - How many amps?

I want my Arduino to drive a LED strip. The LED strip in particular is the 3528 non-waterproof type. To power this up, I need a 12V power supply. My LED strip is going to be 5 meters. Now my ...
1
vote
1answer
59 views

How do I make the letters on my Arduino LED matrix scroll faster?

////************************************************************************* ////----------------1.开发环境:Arduino IDE or Visual Studio 2010---------------- ////----------------2.使用开发板型号:Arduino UNO ...
0
votes
2answers
170 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
2answers
906 views

How do I connect an 8x8 LED RGB matrix to an Uno?

I have this 8x8 LED RGB matrix. How do I get it connected to an Arduino Uno? It came with no other wires/modules/connectors and has a veritable crap-ton of pins to connect.
-2
votes
1answer
31 views

Using two leds with one push button [closed]

How can I make the code of this project where I will press one time a button, to turn on the first led (and turn off second led) and when other one press to turn on second led (and turn off the first ...
1
vote
0answers
27 views

Sketch for 5 randomly fading leds not working as expected; what could be wrong?

I'm working on a project with a starry sky, based on fiberoptics and 5 leds. The code should work this way: Start on average brightness, then go up or down according to a set of randomly chosen ...
1
vote
2answers
4k views

How to make sure Arduino's PWM pulses are phase shifted?

I'd like illuminate my room solely with several RGB LED strips using Arduino's PWM (together with LED amplifier and few transistors). I want the Arduino to control 2 independent chains of LED strips,...
0
votes
1answer
44 views

if/else on digitalRead not executing on 'else' portion

I am a beginner with C++ but used to be good with BASIC (2 decades ago lol). I'm building a peristaltic metered doser that allows you to input desired mL on a 4x4 keypad and then when 'fill' button is ...
0
votes
1answer
20 views

Define preset colors using FastLed library

I'm using an addressable 150 led strip and an Arduino Nano to control it, using FastLed library. I'm tring do create a function turn_on_leds, which gets 4 parameters: 1) delay time for lighting a ...
0
votes
0answers
15 views

How to make an animation with custom WS2812b?

I want to make a diy LED matrix with WS2812b (7x35). I have a difficulty to program the led animation. Is there some kind of program that has easy interface to custom the led display and generate the ...
-1
votes
1answer
53 views

NodeMCU display temperature and control LED from an autorefresh web page

I'm totaly new to Arduino, I'm using ESP2866 NodeMCU and dht22 to display temperature and humidity in a web page, it is autorefresh (using AJAX) and it works perfectly, I wanted to add 2 buttons to it ...
1
vote
1answer
363 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 ...
0
votes
1answer
58 views

How to power multiple LEDs with a microcontroller [closed]

I currently have a "tiny" setup and want to put a few (~20-30) 0402 LEDs on a 1:87 scale car. My current setup is an ATtiny85 USB Mini Dev Board powered by a 90mAh 3.7V LiPo battery which is connected ...
1
vote
1answer
30 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 ...
-1
votes
2answers
38 views

LED not turning on with following code

LED is not turning on with the following code. Have tried multiple LED's and double checked wiring. What's wrong? Using an uno. int ldr = A1; int ldrVal = ldr; int led = 6; int lvalue = 900; void ...
0
votes
1answer
1k 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
3answers
562 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
2answers
40 views

I need help makeing a light flash while a stepper is constantly moving

The starter code. #include <Stepper.h> const int stepsPerRevolution = 120; // change this to fit the number // for your motor of steps per revolution // initialize the stepper library on ...
0
votes
1answer
41 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
0answers
22 views

WS2812 Matrix colour problem. Power?

I have 8 8x8 WS2812 Matrix LED boards connected together to make 2 16x16 matrices. I have them connected with Dupont wires. I also power the 2 16x16 with Dupont wires that are connected to a 5v 60Amp ...
0
votes
1answer
39 views

Trying to Pulse an LED a number of times outside of the main loop

I'm trying to call a class function that pulses an LED "x" number of times. I dont want to use a delay, which is making it tough. If I use a while loop, the LED just stays on. I attach an interrupt in ...
-3
votes
1answer
25 views

How do I turn on/off led with the same IR button? [closed]

I'm trying to make the led switch on/off by the same case(): code. But its not working could anyone help me?
0
votes
3answers
84 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
votes
0answers
189 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
358 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
617 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
30 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
52 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
votes
3answers
452 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
313 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
1answer
71 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
470 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
5k 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
195 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
votes
2answers
224 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 #...
0
votes
1answer
137 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
84 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
103 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
votes
2answers
58 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
174 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
268 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
77 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, ...