hi all
in the bargraph example
http://www.arduino.cc/en/Tutorial/BarGraph
what is the value of the potentiometer,
it is not on the list of parts required
thanks

i have a mega arduino i'm powering the led with a seperate 12volt power supply 100 watts basically i need help with the sketch and what to use a relay of 12 banks or transistors the 4 standard 5mm leds will have only 20mw each x4 = 80mw all on at the same time x 8 or
i think i will use use    
ULN2803A

as with the With 40+ individually addressable LEDs in a tube. sorry should have made myself a little clearer im only wanting 12 banks of 4 leds in my project. maybe something like the nightrider led's but only one sided

hi all again
need help with a simple led design but i havent got a clue where to start ( newbie) i have made some led tubes but i want them to look like snowfall like this

so where do i start ?
do i use a relay module ? transistors and where can i start for the sketch
i have an arduino mega.

thanks
marko

hi all
i have 2 sketches and i want then both to run together one after the other but i'm new to arduino so need help and instructions on how to compile the 2 together if i add the second to the bottom of the other i get
redefinition of void setup so i know i'm doing something wron but dont know what


first sketch


//    FILE: lightning.pde
//  AUTHOR: Rob Tillaart
//    DATE: 2012-05-08
//
// PUPROSE: simulate lighning POC
//
//
#define BETWEEN 2579
#define DURATION 43
#define TIMES 7

#define LEDPIN 13

unsigned long lastTime = 0;
int waitTime = 0;

void setup()
{
  Serial.begin(115200);
  Serial.println("lightning 0.0");

  pinMode(LEDPIN, OUTPUT);
}

void loop()
{
  if (millis() - waitTime > lastTime)  // time for a new flash
  {
    // adjust timing params
    lastTime += waitTime;
    waitTime = random(BETWEEN);

    for (int i=0; i< random(TIMES); i++)
    {
      Serial.println(millis());
      digitalWrite(LEDPIN, HIGH);
      delay(20 + random(DURATION));
      digitalWrite(LEDPIN, LOW);
      delay(10);
    }
  }
 
  // do other stuff here

second sketch

/*
  Blink
  Turns on an LED on for one second, then off for one second, repeatedly.
 
  This example code is in the public domain.
 */
 
// Pin 13 has an LED connected on most Arduino boards.
// give it a name:
int led = 9;

// the setup routine runs once when you press reset:
void setup() {               
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);     
}

// the loop routine runs over and over again forever:
void loop() {
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(150);               // wait for a second
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  delay(5000);               // wait for a second
}

not a problem arduino is new to me as i'm a pic man at heart and the answers i had confused me

vid here

http://s491.photobucket.com/albums/rr277/markosillypig/?action=view&current=DSCN1787.mp4

i used this circuit with an irl520n it works fine any one see any problems ?
a string of led's 900Ma

would the relay module do the job ?
i'm powering a 12volt led strip with 12 volts and just need something to do the switching

i have just tried to add this code to the bottom buttom of the one above

i have changed the code myself to blink like eyes


/*
  Blink
  Turns on an LED on for one second, then off for one second, repeatedly.
 
  This example code is in the public domain.
 */
 
// Pin 13 has an LED connected on most Arduino boards.
// give it a name:
int led = 9;

// the setup routine runs once when you press reset:
void setup() {                
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);    
}

// the loop routine runs over and over again forever:
void loop() {
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(150);               // wait for a second
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  delay(5000);               // wait for a second

thats perfect dude many thanks will an irf530 do the job i have seen on other sites that there compatable with arduino

hi all
i'm looking to find any thing in the forum about thunderstorms but no luck
i am wanting to simulate a thunderstorm with arduno mega nothing flashy just simple i want to drive a strip of led's 900Ma  any help would be appreciated with the code and what hardware to use ie relays or transistors and witch one to use i would like the simulation to work for 3 seconds and a 1 minute pause.

thanks all

marko

light o rama do a unit but its cheep but the software is rediculas in price

thanks i will use mosfets to do the work of the relays just to find sutable mosfets now mm

hi all and welcome to you all
im thinking of buying an ardino but unsure what one to buy i want to controle leds like as seen on this clip

wich arduino would suit me best

cheers marko