First off, thank you to everyone who's posting on this forum. Your input has helped me a great deal up to this point. I have now reached an issue which I cannot find an answer to by simply searching, so I decided to jump onboard and ask myself. =]
I am currently putting together a battery operated Luxeon LED array that is controlled via PWM from an Arduino pro mini. So far, things have worked well. I am able to dim the LED by feeding it to my LED driver's 'EN' pin, which effectively 'turns off' the LED when it is fed a LOW signal, varies the brightness according to PWM values, and keeps the LED to full ON if its not grounded or connected to the arduino.
Now the issue that I'm running into is when I turn my switch on to power the whole setup. The Arduino apparently gives the pin a HIGH signal (or some higher voltage), causing the LED to turn on full for a few seconds until the Arduino is done setting itself up and begins running my program. The same effect happens if I press the reset button. I'm wondering if there is a way to prevent this from happening as the Arduino starts up (code commands), or if there is some sort of hardware method (transistors or diodes perhaps) to keep the EN pin grounded/LOW until it is sent PWM signals from the arduino.
Basically, the goal is to have the LED stay off as I turn on the power, and only turn on when the program starts running.
I'd really appreciate you guys' help. =]