I want to run an +5.0v LCD display from a +3.3v AVR system.
Is it possible or feasible to create the +5v from a voltage doubler on two port pins toggling 3.3v through the diode/capacitor standard voltage doubler?
I thought of using a timer to have Pn.0 and Pn.1 alternate between high and low about 10,000 times a second. When one side is high, the other is low.
Or would it be better to have the main input voltage to the system be +5V (which supplies the LCD)?
Then use a low-dropout voltage regulator to make the 3.3V for the AVR. And finally use a 74HC4050
level shifter to bring the LCD control lines from the 3.3v used by the AVR to the +5v used by the LCD screen.
While I realize that the best approach would be to use a 3.3v LCD display, I want to take advantage of the cheap 16x2 white_chars_on_blue_background LCD modules selling on eBay for a few dollars.
Would this wreck the port pins or the AVR?