Pages: [1]   Go Down
Author Topic: "Waking up" waveform  (Read 1291 times)
0 Members and 1 Guest are viewing this topic.
Offline Offline
Newbie
*
Karma: 0
Posts: 43
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I'm looking for a waveform to drive the brightness of leds so the appearance is that the device with the leds is "waking up". I've done a lot of searching and run off on a lot of unproductive tangents. I have to think that many before me have used creative waveforms in a variety of projects. Any ideas on what to search on ?

I'm thinking of a waveform that has a steep, probably linear  rise to get to max brightness and then some sort of rolloff or decay as the brightness diminishes.

This is for a Stars wars like light saber that I have built, programmed and is complete except for this part. I would like for it to "wake up" as a prelude to the light show.
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 36
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Here ya go buddy. Got this from "Getting Started with Arduino" Book. Have fun! hopefully it'll help... smiley


// Copy and paste this example into an empty Arduino sketch

#define LED   9 // the pin for the LED
int i = 0;      // We’ll use this to count up and down

void setup() {
  pinMode(LED, OUTPUT); // tell Arduino LED is an output
}

void loop(){

  for (i = 0; i < 255; i++) { // loop from 0 to 254 (fade in)
    analogWrite(LED, i);      // set the LED brightness
   
    delay(10); // Wait 10ms because analogWrite
               // is instantaneous and we would
               // not see any change
  }

  for (i = 255; i > 0; i--) { // loop from 255 to 1 (fade out)

    analogWrite(LED, i); // set the LED brightness
    delay(10);           // Wait 10ms
  }

}
Logged

Offline Offline
Newbie
*
Karma: 0
Posts: 43
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Thanks, but I'm way beyond that. I've looked at sine, ramp, exponential and combinations and still haven't found what I want. I have and I suspect many others as well seen what I want in Disney and other children's clips.

Thanks for the thought though.
Logged

Global Moderator
Boston area, metrowest
Offline Offline
Brattain Member
*****
Karma: 536
Posts: 27048
Author of "Arduino for Teens". Available for Design & Build services. Now with Unlimited Eagle board sizes!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

So why not just write that in setup?
Take ebird97s code, increase the count by 10 instead of 1 so it goes up quicker, than change direction and ramp it down by increments of 1 or 2 down to whatever your pre-show level is.
Logged

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Pages: [1]   Go Up
Jump to: