Hi,
I'm using an Duemilanove to power some sensors and a 16 x 2 LCD, but the LCD screen is using to much power and I want to power it with a 9 volt battery. I have been using the 5 volts from the Arduino.
What is the best way to externally (not from the Arduino) power a HD44780 16x2 LCD without frying it?
Im no electronics expert but i think you could get an extrnal voltage regulator, connect the ground to the arduino's ground, and connect the external regulated voltage to the LCD... I think.... anyone wanna confirm that or come up with a better idea?
;D
Azinman is right, get a 5v regulator, throw in 10uF decoupling electolytic capacitors between the input 9v and gnd rail, and the output 5v and gnd rail, and you have yourself a nice, smooth 5v power regulated supply.
for a better descrpition, read "step 2" of this lesson:
Yea I did that with my robot, you can see the little voltage regulator and decoupling capacitors that power the motors on that little perf board underneath the motherboard. http://calebshome.webs.com/CO2.1%20Robot%200080.jpg