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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
votes
1answer
67 views

Why is 8x8 matrix pins do not correspond to rows and columns order?

It would be easier to program led matrix if 1-8 pins corresponded to 1-8 rows and 9-16 pins corresponded to 1-8 columns. Instead there is the following arrangement: Why is it made like this?
0
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2answers
89 views

Getting more current through an LED array

I have an Arduino Uno controlling an array of 24 LEDs (datasheet). I understand these LEDs are ultraviolet and have a forward current of 0.5A. My power source (12V 2A) is wired to a switch which is ...
-1
votes
1answer
224 views

Some questions about a RGB LED Strip project that Im planning to do

Good day all So Im in the planning and research phase of a new project that I want to start for my car. I want to control a bunch of RGB LED strips independently from each other via a micro ...
1
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3answers
455 views

Turning on many (30) leds arduino mega

I´m new working with Arduino. Right now I have a project thar requires to turn on 30 LEDs at the same time with an Arduino Mega. The problem is that it would exceed the max current that the chip can ...
0
votes
1answer
58 views

Powering leds from arduino with adapter

Sorry for having (again) a beginners question, but I was wondering something. If I would want to drive like 20-30 LEDs from an Arduino (Uno), and I want to use an external adapter (12V, 1A), going ...
2
votes
3answers
1k views

Button and switch to turn on and off LED and changing after time

I have system connected to an Arduino Uno where I want to read whether the switch is open or closed. Based on if the switch is open/closed, I want an LED light to turn on/off. When the switch is ...
1
vote
1answer
251 views

Decoupling cap for self-powered LED matrix and LED strip

Should I add a decoupling capacitor to my RGB 16x32 LED matrix powered directly via the 5V pin? When I display a spectrogram, the current load is fluctuating quickly in the 100-250 mA range (on ...
0
votes
1answer
693 views

LED sequence control by button [closed]

I want to make sequential LED by using arduino that controlled by button. If I press + button, LED will increase from L1 to (L1 and L2 is HIGH), then I press button again, L1, L2, and L3 will be HIGH....
1
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1answer
131 views

how to drive 500W of leds

I am currently developing a project that needs 9 led stripes, each led stripe has 5 meters, 300 leds, it consumes 60W per stripe in a total of 540W... This are the led stripes - 5M 12W/M 24V SMD 2835 ...
0
votes
1answer
338 views

Arduino Nano + (2* tlc5940) + 34 LEDs = Power Questions

This is an adapted layout for two tlc5940 hooked up to an Arduino nano. The original project can be found here. I am a little unsure about the capacitors and resistors as that project had it hooked up ...
1
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1answer
35 views

How can I add a LED to this build?

I recreated this project from Fritzing in my circuits.io project then on the arduino itself, it all works fine just how I wanted it. The concept behind it is: You plug it in and the time is set to ...
-1
votes
2answers
186 views

How do I send all notifications from specific apps (like Skype or Facebook) to my Arduino through Wifi?

I am making a project that includes notifying a person through a specific colour on an LED strip. I need to find a way to send all notifications from a specific app to my Arduino through Wifi. It ...
1
vote
2answers
166 views

Controlling a LED array from Arduino NANO

I have a project Im currently busy with that I need a lot of help with. What I want to do i create a flat 8x12 grid of LEDs and be able to control each individual LED independently from the others. I ...
0
votes
2answers
73 views

Make lights come on and off depending on which button is pressed

Imagine a strip of LEDs with O being HIGH and X being LOW. X O X O X Now if I pressed the button below the second O and wanted it to switch the last two LEDs (4th one to LOW and 5th to HIGH or any ...
0
votes
1answer
241 views

Error compiling: expected unqualified id before token {

#include <LiquidCrystal.h> #define trigPin 12 // the trig pin to digital pin 12 #define echoPin 13 // the Echo pin to digital pin 13 #define led 8 #include <Servo.h&...
3
votes
1answer
231 views

Powering the attiny85 with a separate power source

I have an LED project for which i'm using a 9v power supply. For part of the project I'm using an off the shelf LED driver that is compatible with 9v however I have one LED component that I want to ...
1
vote
2answers
414 views

3x3 LED Matrix with less pins

I'm building an audio cable tester/soldering station. XLR cables have 3 pins and they can be wired in a few ways depending on what you want to do. The basic cable is connected 1 for 1 and I want to ...
0
votes
2answers
385 views

Press on pressure sensor once, turn on LED for 6 seconds

I am working on a project where I would like to press on a pressure sensor (0-1024) once and turn on the LED and turn off by itself after 6 seconds. I am quite new to arduino and I can't seem to ...
4
votes
2answers
405 views

Molex power with USB serial Communication from the same PSU

Before I begin I just want to apologize for my mediocre understanding of things electrical and arduino. I know there are a lot of topics similar to this but I'm confused by the term external PSU ...
1
vote
2answers
60 views

When a pushbutton and sensor are in a certain state, do something for a certain period of time (15 seconds)

I have a sketch that contains code for an analog input (FSR sensor), a pushbutton, and 6 blinking LEDs. Currently, the sketch is written to allow the LEDs to blink only when the button is pressed and ...
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
2answers
65 views

i am unable to make a correct program using the pushbutton to toggle LED on/off?

I want to toggle the the LED on on my first complete click(i.e. pushing and even releasing the pushbutton) and i want to make my LED off at my second click. This is the program :- int led = 13; int ...
0
votes
1answer
491 views

How to blink 2 led strips without delay

Hi all I use 2 sensors and 2 led strips. I want to let both led strips light up without interrupting each other while reading the different values from the inputs. But Arduino still pauses when one ...
0
votes
0answers
64 views

Using an Arduino Uno to program a PIC12F1571

I wanted to build my own version of the Pixie, an individually addressable LED. How do I upload code to the PIC12(L)F157X microcontroller? I think the code I want to program is this.
2
votes
1answer
97 views

Matching the blink of an LED to midi music

I have a function that plays a song and lights an LED corresponding to the note that is being played. when the same note is played consecutively(i.e E in bar 6) instead of the LED turning on and off ...
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, ...
2
votes
2answers
365 views

POV using ATmega328 powered with cr2032 cell

I am planning to make a POV (persistence of vision) display using ATmega328 with 5 red LEDs for display. Below are my aims: I want to power it with cr2032 coin cell, so power consumption has to be ...
3
votes
1answer
265 views

Arduino leave PWM on

I am doing an aquarium light sunrise/sunset. Till now programming wise I only did the sunrise. After running the code the light starts to rise up fine, than at full brightness, it turns off. I want ...
6
votes
2answers
6k views

Using a transistor to get 100mA on a IR led

What i saw is that the led use 1.3V on 100mA with a 1:10 Cycle (100ms). Im currently at 30mA using only a 100 resistor, but the range of the led is 20cm at max, i want to get at least 2 meters. Since ...
3
votes
1answer
52 views

What is the correct way to create large project files?

I am currently working on a 10x10 RGB LED screen (using Neopixels from Adafruit) and my project files are starting to get rather large. I have several different devices used in this project: The LED ...
1
vote
1answer
880 views

LED fade with LDR sensor depending on the light

I need help on a project. I just started to experiment with arduino 2 weeks ago and I am building a lamp that react to movement and interactions. So the idea is; when there is nobody in the room, the ...
0
votes
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
703 views

How to drive a strip of 12 V no-addressable LEDs?

I recently bought this LED Strip. I got the 5M 3528 300LEDs SMD RGB Non-waterproof ones. However, I am not sure how to use them. On the strip there is four wires. I have tried supplying power to the ...
0
votes
1answer
58 views

Could someone help me with an Arduino Uno program? [closed]

I am thinking to do a gas leakage and fire detector using a GSM module in my home. I got all the contents like an Arduino Uno, MQ22 gas sensor, LM 35 heat sensor and GSM module SIM800L to send SMS and ...
1
vote
1answer
615 views

Using an Arduino and multiplexer for writing to multiple outputs

I'm attempting to use the multiplexer setup in this article with my Arduino Uno to control the output of LED's, as a way to fully understand the principles of multiplexing. I'm working to modify the ...
0
votes
3answers
66 views

Turning an LED on when an error occurs, then turn it off after 2 seconds

I am currently working on making some test equipment for µUSB cables. The code is supposed to recoqnise when an error in the cable occurs. Most of it works as expected, but I have some trouble ...
3
votes
4answers
2k views

Hex to binary, LED blinking

I need to write a program that takes a user inputted HEX value and converts it to binary, then an LED blinks according to the number of 1's in the binary. For instance, if the value is 0xABC then ...
0
votes
2answers
153 views

Problem connecting 10W led + Led driver Directly Arduino Uno [closed]

can anyone give me an advice on connecting an 10W led + 12 volt drive to an Arduino Uno? it works without the board but when i tried to connect to Uno it doesn't work anymore. Thankyou
3
votes
1answer
3k views

Arduino Nano TX LED is on

My Arduino nano make weired thing... The TX LED is on when i define a Variable and a digital Pin as output. Do you now if it is a error in the code? If I upload a clear new sketch the LED is off. ~...
1
vote
1answer
389 views

Arduino LED Dimmer Proportionate to Ambient Light

I am trying to get an LED dimming reversely proportionate to natural light level in a room. So as the sun rises, the LED dims and vice-versa. I am using the standard LDR+ 10k Ohm resistor divider, an ...
0
votes
2answers
673 views

Light up more than one LED connected to 74HC595 Shift Register

I have a 74HC595 Shift Register with a LED (and resistor) on each of the 8 output pins. I can light them all up I can light one up How do I light two up? For example the one on pin 2 and the one on ...
2
votes
6answers
6k views

Better cycling through the RGB colors

I have been trying to achieve a way to tap into the 16 million colors RGB provides for this LED strip. I thought of using LEDS.setBrightness(); but I have not been successful in my attempts. I have ...
1
vote
1answer
1k views

Why is my circuit working only when I touch it?

I have connected digital pin 2 of arduino to the circuit as shown: The problem is that the LED is not turning on normally its only turning on when I touch anything on collector side of circuit. What ...
-1
votes
3answers
876 views

Blink 2 LEDs one at a time every x seconds

Newbie here - literally opened my Arduino about 3 hours ago. I have been able to code 2 LEDs to blink randomly, but what I want to do is have one of the two blink every 10 seconds. My current code: ...
0
votes
4answers
6k 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
1answer
50 views

Input-Output Circuit Issue

I have design a circuit with 2 led (red and UV) and 2 button.So, the circuit supposed to work like this: If i press the button for red led, the red led lights up and the uv led turn off, and if i ...
0
votes
1answer
1k views

5pt font for Neopixel shield

I have a 5x8 Neopixel shield for my Arduino. I want to display text on it, while it is in "landscape mode", i.e. a only 5pt high text. The default font that is used by the printcommand is 8pt high. ...
0
votes
3answers
284 views

MAX7219 not behaving as expected

I have 2 rows of 12 MAX7219 connected in series with DOUT to DIN (rows are isolated). Now the thing is I am using LedControl Library to work with it. The problem is the last 4 Matrices on both the ...
0
votes
1answer
1k views

Why is the piezo buzzer not making any sound?

My ciruit: My code: // Pin 13 has a LED connected on most Arduino boards. // give it a name: int led = 13; const int buttonPin = 2; // the setup routine runs once when you press reset: void setup() ...
2
votes
5answers
5k views

Stop Led's from blinking

My code: // Pin 13 has a LED connected on most Arduino boards. // give it a name: int led = 13; const int buttonPin = 2; // the setup routine runs once when you press reset: void setup() { // ...