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### Topic: 3v voltage for Nokia LCD (Read 1 time)previous topic - next topic

#### hansibull

##### May 03, 2012, 02:42 pm
Hi!
I just bought a Nokia 5110 LCD module for arduino, but the datasheet says that the LCD only can handle 3 volts. since arduino are running at 5 volts, how can I convert the voltage from 5 to 3 volt?

will it be possible to use a resistor, how many ohms?

http://www.ebay.com/itm/260967834595?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649#ht_2805wt_986

Greetings
MightyCore -  ATmega1284, mega644, mega324, mega164, mega32, mega16, mega8535
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#### iyahdub

#1
##### May 03, 2012, 03:19 pm
74LCX245 can be used for the 5v-3v conversion, and for example sparkfun uses the lcd driver PCD8544 which is a one in all chip. So if u bought a shield for it probably already has a chip controlling that !! If its a recovered one, theres schematics and examples abound on the net !!
10 LET Loop=Infinite
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#### Grumpy_Mike

#2
##### May 03, 2012, 03:42 pm
Quote
will it be possible to use a resistor,

No.

You need both a signal level shifter and also a 3V supply. The arduino has a 3.3 volt regulator but that is too much for you. You need a linear voltage regulator to change your 5V to 3V.

#### iyahdub

#3
##### May 03, 2012, 05:05 pm
3 .3Vwill do,  anyway.  so that is sorted. As i said the PCD8544 will do most of the work for you. you will find a schematic for it quite easy on the net. there are also other solutions though, as level shifter goes
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#### iyahdub

#4
##### May 03, 2012, 05:08 pm
http://code.google.com/p/pcd8544/
a   library for that chip with detailed info
10 LET Loop=Infinite
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#### Grumpy_Mike

#5
##### May 03, 2012, 06:22 pm
Quote
3 .3Vwill do,  anyway.  so that is sorted.

So it's less current than the 50mA capability is it? I don't see where it says that.

#### iyahdub

#6
##### May 03, 2012, 10:15 pm
Well, despite never have tried it myself, i have seen it done, and you can confirm theres hundreds of successful projects online as well( which confirms what i have seen with my eyes) so, it works. Been a while and my mates still working ?!?! You gonna try deny that ?!?
I posted just one of the many online ( have u seen it at least ?!?0
So for that matter, solves his problem... Sparkfun sells a shield based on that same chip and method
10 LET Loop=Infinite
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#### Grumpy_Mike

#7
##### May 03, 2012, 10:22 pm
Quote
You gonna try deny that ?!?

Never denied anything, I was just asking the questions that any one undertaking a project should ask.

Quote
nd you can confirm theres hundreds of successful projects online

The definition of success is very dilute in electronics on the web, as witnessed all those projects that do not use any current limiting in LEDs. LOL shield any one? Utter crap design.

#### iyahdub

#8
##### May 03, 2012, 10:48 pm
Yeah you are right about the last one, and i didnt affirmed you had denied it.
But it works -here is why :
Quote
PCD8544 is a low power CMOS LCD controller/driver All necessary functions for the display are provided in a single chip, including on-chip generation of LCD supply and bias voltages,
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