Tagged Questions

1
vote
1answer
53 views

Multiplexing with or without transistors

I'm doing something in where I need to multiplex 6 7-segment displays. About doing it, I found things like this: And things in where the same thing is done without the transistors, just by ...
2
votes
1answer
59 views

Need help setting up 7X6 Piranha LED Matrix with Arduino

I need help correctly getting my parts list for a 7X6 matrix that will be part of a electronic outdoor scoreboard. Here is my parts list so far but I am stump whether the arduino is powerful enough ...
1
vote
1answer
40 views

Does a photo-coupled SSR need a series resistor for the internal LED?

I am trying to control an LCA710 SSR with an Arduino digital output. The data sheet says the control inputs are "CMOS and TTL compatible". It also has a schematic of the internals of the chip, showing ...
1
vote
2answers
63 views

how many resistance do i need to safe the LED of PC814?

if i have a input of 5v (arduino HIGH) on the LED of a PC814, how is the value of the resistance that i must use before that, so i don't burn the led? ...
1
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2answers
63 views

Arduino multiplexing help needed.

Is it possible to use an 8 output demux to switch between seven 16 output demux's in the case that I want to control several LED's with an arduino uno? Is there a better way to do this?
2
votes
2answers
48 views

Simulate a bouncing ball on a LED cube

I just finished working on my 4x4x4 LED cube. I am trying to write an animation for a bouncing ball in the cube. Basically, a ball either 1 LED big, or 2x2 LEDs big should be moving around within the ...
5
votes
4answers
19 views

How can I control more than 64 LEDs using a Uno?

I finished working on my 4x4x4 LED cube. I want to make a larger 6x6x6 cube. Is this possible ? Which components should I use to control the LEDs ?
8
votes
4answers
58 views

How should I light up all the LEDs?

I am working on a 4x4x4 LED cube. I have connected all the negative terminals of LEDs in a horizontal layer to each other, and am using one Arduino pin per layer. I have connected all the LED positive ...
3
votes
3answers
166 views

Turning on multiple leds with arduino using transistor

I want to be able to turn on 50 red LEDs with one pin of an Arduino. I don't want individual control, I just want to be able to turn them all on or all off. I found this example. It uses a 2N3904 ...
0
votes
1answer
132 views

Receiving SMS using GSM and controlling LED using Arduino

Has someone come up with a solution with the above stated problem? We are using Arduino Duemilanove and SIM 900 GSM module ...
1
vote
2answers
115 views

Controlling a Servo with a TLC5940 (calculating PWM setting)

I'm trying to control a few servos and a bunch of RGB-LED from an arduino board. To do that I'm going to chain together a few TLC5940 chips. The issue I'm trying to resolve at the moment is what PWM ...
2
votes
2answers
198 views

leds in parallel, switched with NPN transistors

I have the following circuit designed to drive 3 PWM pins off a 3v3 Arduino Pro Mini -- one pin for each of R, G, B in this set of 5 RGB LEDs. simulate this circuit – Schematic created ...
1
vote
1answer
124 views

Hooking up multiple RGB LEDs while using a minimal number of PWM pins on an Arduino?

I currently have an anode RGB connected to the 11, 10, & 9 PWM pins on my arduino. However I would like to add 3 more LED's to my project, but I don't want to necessarily take up every single PWM ...
2
votes
2answers
211 views

Controlling a LED's intensity with a text file from an SD card

I need your help for a project. My equipment: Arduino Uno, microSD Shield, power LED shield, micro SD card First, I want to control the intensity of a led by reading a text file. Here is an example ...
1
vote
0answers
449 views

Arduino IR Transmitter & Receiver w/ LEDs Flickering Issue (What's wrong with this circuit?)

I have an Arduino Uno connected to two IR transmitters and respective receivers. Basically, when one of the receivers detects a beam break, I have a strand of LEDs display a pattern. This all works in ...
2
votes
2answers
144 views

Driving 3.3 V LEDs with an Arduino and a shift register

I'm planning to build a simple LED matrix with an Arduino and some 74HC595 shift registers. However my Ardiuno outputs 5 V to the registers which will pass that 5 V on. How and where along the line do ...
0
votes
1answer
144 views

How do I use this LED strip?

I got this LED strip that I'm trying to control with my arduino. I searched for similar strips online but couldn't find any. I only has leads for DIN (blue), GND (black, splits in 2), and +5V (red). I ...
1
vote
2answers
259 views

Help verify 8x8x8 LED cube circuit

I am a beginning hobbyist when it comes to electronics. I have read lots of theory but I only have a little bit of hands on experience. I would like to build an 8x8x8 LED cube and I came up with this ...
0
votes
2answers
273 views

coding using Arduino, two 74HC595 and two RGB LED, problems with shifting out database

the whole point of this was to be able to send 8 bits of color code to 2 rgb leds through 2 74hc595 registers. if i can get the default color for each led to be sent out then the next part of code is ...
6
votes
1answer
332 views

Accidentally made an analogue touch sensor from arduino digital pins

The other day I wrote a simple arduino script to switch on an LED when a pushbutton is pressed. Without connecting the pushbutton, the circuit created a make-shift analogue sensor that varies the LED ...
2
votes
2answers
179 views

Sync 12 Arduinos - I2C vs Serial

I've been given 12 arduinos (Mega) and 12 breakout boards (custom built. they pump up the output of the digital pins to 12v @120mA) to control around 300 LEDs. I'm using a pseudo PWM library to fade ...
1
vote
1answer
401 views

How to drive high power LED and Arduino by the same power source?

I am building a plant light consisted of 24 high power LEDs (Cree ML-E) and an Arduino Uno. I would like to power the LEDs and the Arduino by the same power source. Since creating circuits for dealing ...
2
votes
1answer
122 views

TLC59116F (i2c led driver) everything seems ok but LED doesn't work

I'm trying the LED driver TLC59116F with an arduino UNO R3. This IC is a i2c controllable LED driver with PWM and 16 outputs. The registers seem all loaded fine, here's a print of their contents: ...
1
vote
1answer
265 views

Multiplexing an 8x8 Matrix - Why Transistors?

I'm trying to understand how to properly multiplex an 8x8 matrix (or any large amount of LEDs) http://arduino.cc/en/Tutorial/RowColumnScanning However, I'm getting a bit confused, since I've found ...
0
votes
1answer
110 views

virtual light communication

I have to design a project that uses an LED to transmit data and a LDR to receive the data or signal from the LED. But the problem is I have to use two Arduino UNO boards, one for LED transmit and ...
-1
votes
1answer
186 views

Help with code on 4 x 4 x4 LED cube with Arduino? [closed]

Recently I made a LED cube, on my own, and I want it to display characters, alphabets numbers going layer by layer using the concept of multiplexing and POV (persistence of vision). I googled a lot, ...
2
votes
4answers
347 views

Need a LED Display

PROJECT: I'm building a Digital Clock controlled by a Arduino micro-controller. I want it to display the hours, minutes and seconds on a LED Digit Display. Therefore, I need to have several digits, ...
3
votes
1answer
165 views

Long Chains of Shift Registers

I want to set up an LED display, and I'm looking at using a bunch of 16-bit LED driver chips (like TI TLC5927) to run a 16x16 LED matrix. Then I'd like to maybe put a few of these 16x16 displays ...
1
vote
1answer
213 views

My LED strip arduino setup doesn't use a resistor. Is that okay?

Very beginner with this. I am powering an analog LED strip (10 sections, total 12 V, 200 mA required). I'm using a N-MOSFET and an arduino to fade in/out the lights. From my calculations I don't need ...
3
votes
1answer
303 views

How to stop a switched current affecting an IC?

I have 10 circuits each consisting of a Touch IC (Atmel at42qt1010) and electrode, and 2 x 350mA Constant current regulators (NSI50350AST3G) and LED's. All connected to a Arduino Mega, by ~1 meter ...
1
vote
1answer
652 views

Building a 3x3x3 LED cube?

I need to built a 3x3x3 LED cube. I need to be able to turn every LED on (not at the same time) in different patterns. I need to use Charlieplexing (note that any other method is not a viable ...
5
votes
2answers
235 views

'long' distance arduino daisy chain

I have a large shelf (like 5-10meters, or 15-30 feet long) which I want to put an LED in at every level. Thing like a positional system for a mini-library. I have a litte problem to efficiently drive ...
6
votes
3answers
566 views

Best way to control 130 - 140 LEDS with Arduino Uno 32/64 bit led drivers?

I am new to electronic prototyping and had a few questions. I need to control 132 LEDs individually. I want to make 3 rows ( 2 rows of 60 and 1 row of 12) I think i can matrix them but i would still ...
2
votes
1answer
109 views

Strange Results With a 3x7 Segment LEDs

I'm trying to get a CPS03631BR 3 digit 7 segments LEDs to work. I've wired it to my Arduino UNO like this: And I'm using this code, which should light all the LEDs digit-by-digit, then light ...
0
votes
0answers
420 views

How to Create an RGB LED Display for Raspberry Pi?

I'm relatively new to hardware. I have some basic concepts down and I've only done some basic circuitry, but I really want to jump into the deep end - it's how I learn best. I'm not sure how simple ...
6
votes
1answer
197 views

RGB LED - Set intensity on Red and Blue

I've recently purchased SparkFun's starter arduino kit, which comes with a 4-legged RGB LED. If I understand correctly, this RGB LED should be able to access the full range of RGB colors, with 255 ...
1
vote
2answers
1k views

Arduino/Raspberry Pi 2 LED Matrices

Does anyone know if I can use a single Arduino or Raspberry Pi to control two 32x32 LED matrices as sold on the Adafruit website? Here is a tutorial where you can wire the 32x32 matrix. Ideally, I'd ...
0
votes
2answers
196 views

Anode RGB LED Arduino Hookup Confusion

I'm having a really hard time getting this RGB Led working with my arduino. First i'll describe my setup (schematic) , and then i'll show you the code I have. I have 5 volts going into the second pin ...
3
votes
2answers
269 views

Will my Arduino output pin at 0v handle 25 LEDs cathodes

Short question: Is it safe to connect a single Arduino ADK (Mega) output pin at 0v to 25 LEDs, each with an appopriate 100 ohm resistor, and each being powered by a output pin at 5v? i.e. 25 output ...
1
vote
4answers
1k views

20x20 RGB LED Matrix controller project

I've been wanting to start a project with the following requirements: Be able to display a static image, composed of 19x19 RGB pixels (though I expect to have to use a 20x20 matrix). Be small (in ...
4
votes
2answers
320 views

Powering RGB LED's and using a PWM chip; series or parallel?

I'm working on a hobby project where I will be using an Arduino board and a TLC 5940 to control 5 different groups of RGB LED's. The number of LED's in any particular group will not necessarily match ...
0
votes
1answer
522 views

How to power an arduino controlled string of RGB LED's from separate power source

I'm new to electronics and working on a hobby project that will have an arduino board running 5 separate strings of RGB LED's. I'll be using a PWM chip (TLC 5940) so I can independently control tho ...
2
votes
5answers
973 views

How do I control several hundred individual leds with Arduino(s)?

I am working on an electronics project which involves hundreds of LEDs. (Talking upwards of six to seven hundred LEDs...a lot, I know.) Is there any way to control this many LEDs with one or a couple ...
4
votes
4answers
775 views

Driving LEDs at long distance

I'm looking to drive 52 LEDs (datasheet), around a large inflatable tent. The LEDs have a forward voltage of 3.3V, at a maximum of 20mA. I'm thinking of using the NXP SAA1064 I²C 16-channel LED ...
2
votes
2answers
228 views

Keeping power to arduino after mains shutdown

I have had ideas for an arduino-controlled led-lamp for a while now. It's mostly fancypants stuff, but could be fun. The lamp is made up of several individually controllable leds. And on power-on I ...
0
votes
1answer
309 views

7-color RGB LED Help

I bought a 3 legged Blinking (I have a theory this might be my problem) RGB LED from Radio Shack. I am not quite sure on how to code my arduino to make it emit one solid color constantly. The closest ...
0
votes
0answers
146 views

srand in an array?

Most the documentation I have found is using print for a random number generator but I can't get an idea of what to do. I need it for an array of leds. If someone has an idea of where to start let me ...
1
vote
1answer
196 views

Is it possible to add a piezo buzzer to a counter

Is it possible to add a piezo buzzer to a counter: my example: (countD<70) so 1 melody at =0 2nd melody 10,20,30,40,50,60 3rd melody 70 This is what I was playing around with: ...
1
vote
1answer
303 views

Controlling colors in RGB LED

I have RGB LED(s) similar to the the 5mm in the pic. I have had success in uploading the example Blink program and testing it with a single LED connected to pin 13 of my Arduino Nano/ATMEGA328. The ...
2
votes
1answer
123 views

Patterns for a strip of leds

I am working on how to get a strip of 60 leds to generate a pattern or how to get at least a running light with 8 on leds. So I have two questions a) Can they it be done without the help of Arduino or ...

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