Pages: [1]   Go Down
Author Topic: confused about order of operations in blink demo [solved]  (Read 624 times)
0 Members and 1 Guest are viewing this topic.
0
Offline Offline
Newbie
*
Karma: 0
Posts: 5
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I'm playing with the built-in blink example, and am confused about why things are working as they are.  In the following code snippet:

Code:
void loop() {
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);               // wait for a second
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  delay(4000);               // wait for a second
}

I would expect this to light up the LED, wait for 1 sec, then turn it off and wait for 4 sec.  However, the opposite is true.  It lights up, stays lit for 4 seconds, then turns off and waits for 1 second.

I a little bit feel like I'm going crazy here.  Why is it reverse of what I expect?
« Last Edit: January 09, 2013, 01:47:51 am by Nick Gammon » Logged

Offline Offline
Edison Member
*
Karma: 64
Posts: 2484
The last thing you did is where you should start looking.
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Is your LED with resistor going to ground?
Logged

0
Offline Offline
Newbie
*
Karma: 0
Posts: 5
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

ah, that was it.  thanks!
Logged

Pages: [1]   Go Up
Jump to: