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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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1answer
41 views

RGB LED strip green LEDs cannot be dimmed to less than 50%

I have an RGB LED strip which I want to control with my arduino uno, everything works fine, except for the green LEDs. They cannot be dimmed to less than 50%, because they will simply turn off. I ...
0
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1answer
455 views

Electric meter pulse counting using LLC

I am trying to create an electric meter reading setup for Arduino, and I have been searching for it and almost every posts available is using LDR sensor. http://www.reuk.co.uk/wordpress/solar/...
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3answers
96 views

Turn on each of the LEDs in order, by setting the cycle delay to 100 milliseconds

I have a tutorial to finish and I don't know the code I have to use to make all (4 LEDs) to turn on in order. So this is my code and my simulation. Thanks in advance! My Code: void setup() { ...
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1answer
181 views

How to scroll data in LED dot matrix through multiple modules?

I've been struggling in this issue for a long time, I know there are people who have done it. But, I don't have much experience in C to have the skills to design or develop such complicated functions....
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1answer
195 views

AnalogWrite only working for one pin of RGB LED

I'm working on some code for a Nerf blaster with an LED indicator light. When attempting to use analogWrite to PWM my LED pins, only one pin (blue) behaves as expected and dims down. The other two (...
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1answer
39 views

yellow LED not turning off in traffic light simulation

I wanted to make a simulation of a traffic light, and since I don't have any sensors I used a button to change between the different states (red/stop and green/drive). When the states are changing I ...
0
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1answer
58 views

How to replace the delay() function in my code?

I'm new to Arduino and I currently have a project that involves the control of an LED via ultrasonic sensor. Basically, if an object passes through the ultrasonic sensor, the LED will be ON for 5 ...
0
votes
1answer
46 views

arduino rfid with led, code is compiling but not working as expected! [closed]

code is compiling, what I want is that when rfid tag kept led should get on but instead its getting to the else loop. int count = 0; char input[12]; // rfid input int led = 3; // led pin char first[...
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1answer
363 views

How to blink the LED forever when detect an object is more than 30 cm away using ultrasonic sensor

I would like to make an alarm system using ultrasonic sensor. My aim is to blink an LED for ever once ultrasonic sensor detect an object is more than 30 cm away. But the problem is that my code some ...
0
votes
1answer
38 views

how to make this work auto on off led with fading [closed]

I'm working on a project with Arduino to make LED timer with fading feature. After doing some research finally I wrote some code but it's not working until now P.S i don't have any knowledge in coding ...
0
votes
1answer
76 views

LED staying on after first relay trigger [closed]

I seem to have a strange issue with a simple circuit involving a relay. The problem is that the relay appears to work absolutely fine (judging from the onboard led) but the the led stays on after ...
1
vote
1answer
116 views

Confusion over Transistors for a switching circuit with an Arduino Mega 2560

Apologies if this is a stupid question asked by a noob, but I've looked around to try and find the answer and just can't work it out. Basically, I'm making a project on thingiverse (Glitch's MK2 ...
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1answer
1k views

LED blinking count with LDR sensor [closed]

How to count +1 all the time if LED blinks with LDR sensor Image: If i turn on led it must count into serial monitor 1 and if i turn off led and turn on again then it counts 2. To turn on led I ...
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votes
1answer
83 views

Joysitck with servo, LED array and buzzer [closed]

Does anybody know of a sketch that can turn a single servo 180 degrees clockwise/counterclockwise with the x axis of a joystick, light a bar graph LED with the Y axis, and sound a buzzer when the ...
-1
votes
2answers
51 views

Why the program keeps applying what is in loop in first case and stops in the second one? [closed]

In the first program after removing hand from the button it keeps on, means it keeps applying what is in the loop: int led = 13; int button = 12; void setup() { pinMode(led, OUTPUT); pinMode(...
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2answers
170 views

Multiple LED on arduino [closed]

I am currently trying to control multiple LEDs with one Arduino Mega 2560 board. However, since each LED needs 3.6 volts and the board only supplies 5V I cannot make more than one light up. Is there ...
3
votes
5answers
533 views

Emergency Vehicle - Make two LEDs flash with buttons and a passive buzzer change sound

My Dad and I are just learning how to use my new UNO. We have learned how to make leds flash at the touch of a button. We have also learned how to make a passive buzzer sound at the touch of a ...
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0answers
164 views

Push button to LED Code does not Properly Execute

I was making a program that would randomly select an order of lights utilizing the random-seed and random functions in Arduino. After selecting an order randomly, the LEDs would proceed to go off ...
1
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1answer
194 views

Portal gun sound effects and lights

I'm building a portal gun from the game Portal and I'm struggling with the wiring for the lights and sound. I've the lights working using the first image from Instructables and adding more LEDs ...
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0answers
35 views

What am I doing wrong? (LED PROBS)

I have chopped up and spliced together some USB cables to combine with several strips of LEDs to create (what should be) a daisy-chainable setup that I can use to make a light fixture. Below is a ...
0
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1answer
66 views

How can I light one led from two different sensors?

I want to light one led with two sensors, the first one is a PIR and the other one is a Photocell sensor. The idea is to turn on the led if the PIR sensor detects movement, and also to turn the led ...
2
votes
1answer
93 views

LED fade class strobes for unknown reason

Okay, so here is what I'm trying to accomplish: I have four LEDs, under my fish tank, that I want to fade in and out. I want each LED to fade at a different rate, start at a different "brightness" ...
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1answer
1k views

Arduino Uno: Driving a small LED strip with 2N3904 NPN

I'd like to know why I cannot dim the small LED strip with my design. I can only turn them on and off. This is a problem for me as I wanted to have a fade effect. Here is my circuit: The voltage from ...
1
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2answers
413 views

How to fade an LED in response to a sensor?

As the sensor "sees" an object nearby, it makes the LED go to full brightness and it remains like that for as long as the sensor keeps on sensing the object. Then, as soon as the sensor stops sensing ...
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3answers
2k views

Change the sequence of LEDs with button press

I am new to arduino. I have created a circuit , here is the image: I want something that as I press the button the sequence of LEDs will change and as I press the button again , the sequence will ...
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0answers
139 views

Can 2 or more LED strobe Lights Flash in Sync?

I'm trying to build a strobe light that has at least 1 mode that can sync with another unit. The strobe light has 2 colors, white and red which are driven by 2 qlite drivers which are controlled by ...
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0answers
67 views

Arduino Code hang

I am working on a project to dim/brighten the LED lights between each hour. To make the program readable i have only kept the code for few hours. For example if T1 is at 255 PWM and T2 is 20 PWM, the ...
0
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0answers
138 views

Fading 5 LED strips

I'm trying to fade 5 led strips (12 V with MOSFET), with push of a button. A user can push any or multiple buttons and leds fade in, when button is released, they slowly fade out. Now I almost got It ...
1
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2answers
331 views

Arduino LED flashes with one button press

I want the LED to flash when I press the switch once, but it keeps flashing. I tried the idea of just lighting the LED and keeping it lit with just one button press, so I wrote: int led=13,button=12; ...
3
votes
1answer
269 views

Overheating Shift-Register(74HC595)

I am working on a project where I need to use around 50 LED's connected to an Arduino UNO board. To begin with i worked on the tutorial provided by Arduino (https://www.arduino.cc/en/Tutorial/ShiftOut)...
1
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1answer
451 views

Do I have to wire up my WS2812 LED strip in “series”, if I want to address each LED individually?

Let's assume I want to make an asterisk (*) out of LED strips. I want to control each leg individually, while still being connected to only one GPIO pin. The layout I had in mind, looks like this: ...
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votes
2answers
133 views

How to identify RGBW LED pins? [closed]

I have a RGBW LED but I don't know how to identify the negative and the colors pins. I tried different combinations with an Arduino Uno but it never produce light. I never used it so I am not sure ...
-1
votes
1answer
27 views

How do I write a program that turns on both on board LEDS ONLY when BOTH switches are ON [closed]

int btn1=0; int btn2=0; void setup() { // put your setup code here, to run once: pinMode(GREEN_LED,OUTPUT); digitalWrite(GREEN_LED,HIGH); pinMode(RED_LED,OUTPUT); digitalWrite(RED_LED,HIGH)...
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votes
1answer
24 views

Tinyduino I/O line voltage level

Does anyone know what the I/O line voltage level is on the Tinyduino? Tinyduino I want to run a MAX7219 LED array with it, like this one: LED Array
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1answer
384 views

MAX7219 library that can compensate for poorly designed/miswired 8x32 panel?

I have this sample code: #include <MD_Parola.h> #include <MD_MAX72xx.h> #include <SPI.h> #define MAX_DEVICES 4 #define CLK_PIN 11 #define DATA_PIN 12 #define CS_PIN 10 ...
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3answers
80 views

prgramming arduino led on then off

i want the led to light at the beginning and stays like this for a while then turns off, so i wrote: int led=13; void setup() { pinMode(led,OUTPUT); } void loop() { digitalWrite(led,HIGH); ...
-1
votes
3answers
77 views

Yellow LED got burned, green LED didn't [closed]

I'm not talking about the onboard LED at the Arduino board here. What those LED's mean, is the LED's we usually plug at the breadboard. I plugged in a yellow LED and a green LED onto a breadboard. ...
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2answers
76 views

I am having trouble with fading two LEDs

I've tried to modify this code, but everything I tried failed. Where am I going wrong? All I want to happen is when button 1 is pressed LED 1 fades up and when released LED 1 fades out and the same ...
2
votes
1answer
703 views

Control LED strip IR controller using Arduino

Is it possible to connect to one of these, which run at 12v, to turn on the LED strip using an ESP8266? It doesn't matter if it's an Arduino or the ESP8266, both should be able to do this. The board ...
0
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0answers
111 views

Arduino: Output state of pin (~3) running PWM signal. Is it ON or OFF?

On my Arduino UNO, I have set pin ~3 to run PWM. Is there a way to know when the signal is ON and when it is OFF? I am trying to eliminate background noise from an LED light intensity reading by ...
0
votes
1answer
75 views

Arduino UNO Intro to Engineering Project [closed]

I am a college student in an intro to engineering class looking to create a final project. My goal is to create a small "present" that opens its lid via a servo and plays jingle bells with LEDs ...
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4answers
2k views

Using a button to toggle an LED ON/OFF

I'm fairly new to Arduino and am trying to use a push button to toggle an LED on and off using a momentary press of the button. This code is lifted straight off the tutorial on the Arduino website but ...
1
vote
2answers
89 views

Turning a motor on and a led at the same time for a given time period

I need help with this code, I want to have a motor turn on for a given time and at the same time have an led light up to indicate it is on which will also turn of once the motor has stopped. It is ...
1
vote
3answers
362 views

Analog input draws current when Arduino is turned off

I am using a Arduino Pro Micro from SparkFun (similar to Arduino Leonardo, cpu: Atmega 32u4). It has a analog input: A0, which I use to keep track of the battery voltage in my battery powered project (...
1
vote
1answer
84 views

8 x 8 led matrix module [closed]

I just bought 4 8x8 led matrix module from online store...when I connect the led module to arduino and computer without any program, the led shows weird pattern (isn't that is should show all 64 led ...
1
vote
0answers
471 views

Switch on/off LED 24V using a MOSFET

I try to switch on/off IKEA Ledberg LEDs which are powered with 24 V using the setup from this tutorial video: https://www.youtube.com/watch?v=sVyi7yWuXxs I use a IRLB8721PBF MOSFET. When I switch ...
0
votes
1answer
118 views

Arduino Mega 2560 LED is dim when powered from digital output

My circuit is a simple one, I am using an arduino atmega 2560. One 5mm red LED connected in series with a 150 ohm resistor. If I didn't make some kind of goof, a red LED has a voltage drop of 2 volts ...
1
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3answers
304 views

How do I call functions sequentially without using the Delay function?

I've been messing with the Adafruit Neopixel lib, and I'm trying to replace some of the delay functions with mills ( so that I don't block the serial port ). So far I have the following code; void ...
1
vote
2answers
316 views

How do I set a continuous servo to turn on until a switch is flicked?

I am trying to get a servo to be activated by a momentary button. The arm on the servo will then swing around, which then activates a toggle switch. The activation of this toggle switch will then ...
1
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0answers
134 views

Sparkfun Spectrum Analyzer: Problems with frequency bands

I bought around 2 years ago the Spectrum Analyzer Shield from Sparkfun, but I never had the time to do something with it. Recently I found the time to start a project to build a graphical equalizer. ...