Hi all, i just ordered my first LCD to start playing around with, on the suppliers site it says "Utilizes the common ST7066/HD44780 parallel interface" and it goes on to say that "You will need ~11 general I/O pins to interface to this LCD screen."! would it be possible to use a shift register such as the 74HC595 to reduce the number of pins needed? i read somewhere that it was described as a serial to parallel converter.
At the moment i don't fully under stand how the 74HC595 works. i just did a tutorial where you use a shiftout function to essentially make 8 LED's count to 256 in binary. Which was cool in a geeky way
So can you use the 75HC595 to reduce the number of pins needed for the LCD screen? Anyone done something like that before?
Yes, you can save I/O pins usig a shift register. Do a search from the arduino.cc homepage, and you'll find examples (and even a library for use with the HC595, iirc).
Note that the spec sheet you referenced is for a display designed to run off 3.3V. Unless you're using a 3.3V Arduino (like the Lilypad or some of the Pro Mini versions), you may damage the display by hooking it up to a 5V system. The logic inputs are probably (but not certainly) 5V-tolerant, but the LED backlight probably has its current-limiting resistor set for 3.3V. There's a decent chance that it won't last long at 5V.
Note that the spec sheet you referenced is for a display designed to run off 3.3V. Unless you're using a 3.3V Arduino (like the Lilypad or some of the Pro Mini versions), you may damage the display by hooking it up to a 5V system. The logic inputs are probably (but not certainly) 5V-tolerant, but the LED backlight probably has its current-limiting resistor set for 3.3V. There's a decent chance that it won't last long at 5V.
Oh I didn't see that. I guess I have learnt my lesson. Any tips on how i can safely get it down to 3.3V? I am working my way through some some info i found on google but their seems to be a few different methods.
Well i got in contact with the online store and asked them to change it to the 5V equivalent. Hopefully it hasn't been shipped yet and they can change it. either way i will be a good learning experience.
The signal pins can be cut down with a potential divider.
Hmmm ok, I have been looking around, doing some googleing but i am a bit lost. How do i know/work out what one i would need? do you know where i could find some info about them... do you know of some good documentation...
Ok, so by looking at that schematic I did the maths it should put out 3.24V { 3.24=5x3300/(1800+3300) } So using that method for the 6 pins and using the voltage regulator for the power supply.
I didn't see that. I guess I have learnt my lesson. Any tips on how i can safely get it down to 3.3V? I am working my way through some some info i found on google but their seems to be a few different methods.