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I just drove 3 hours to an electronics shop only to find they didnt have the IC I needed...I am new to this so I dont know much about what hardware spends I need...


http://www.ladyada.net/products/nokia5110/#wiring

^ that is the tutorial I was following and for that I need a 74HC4050 IC which is a level shifter but store doesnt have them...I am at a restaurant with wifi right now since I dont want to travel home and then travel another 3 hours...

What alternative ICs are there to that IC that would work? I can buy them from the shop if they have those alternatives...


also, I bought 2.8V Led 20 mA, would that work with arduino or do I need to buy some resistors?

Thank you for all your help!
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I just drove 3 hours to an electronics shop only to find they didnt have the IC I needed...I am new to this so I dont know much about what hardware spends I need...


http://www.ladyada.net/products/nokia5110/#wiring

^ that is the tutorial I was following and for that I need a 74HC4050 IC which is a level shifter but store doesnt have them...I am at a restaurant with wifi right now since I dont want to travel home and then travel another 3 hours...

What alternative ICs are there to that IC that would work? I can buy them from the shop if they have those alternatives...


also, I bought 2.8V Led 20 mA, would that work with arduino or do I need to buy some resistors?

Thank you for all your help!
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I just drove 3 hours to an electronics shop only to find they didnt have the IC I needed...I am new to this so I dont know much about what hardware spends I need...


http://www.ladyada.net/products/nokia5110/#wiring

^ that is the tutorial I was following and for that I need a 74HC4050 IC which is a level shifter but store doesnt have them...I am at a restaurant with wifi right now since I dont want to travel home and then travel another 3 hours...

What alternative ICs are there to that IC that would work? I can buy them from the shop if they have those alternatives...


also, I bought 2.8V Led 20 mA, would that work with arduino or do I need to buy some resistors?

Thank you for all your help!
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Let's start with the simple one.

For the LEDs you will need resistors - 120Ω to 150Ω should be fine (R=V/I = (5 - 2.smiley-cool / 0.02).

As for the chip, all that does is convert the 0-5V of the arduino to the 0-3.3V that the display needs.  You can achieve the same result in a large number of ways, not all requiring a chip.

For low-speed communications resistors arranged in "potential dividers" can be used.  For higher speed you can use diodes, transistors, any number of methods.
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You might find this video by Jeri Ellsworth helpful.



Have you thought about using a voltage divider if you're going from 5v to 3v3 in one direction?
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I've merged these to save anyone else wasting their time.

OP, DO NOT CROSS POST.
Is that clear enough?
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okay guys. Thank you! I got home and ended up ordering that chip on ebay (Initially I didnt because I am short on time which is an issue when shipping is concerned) In the meantime I will build a voltage divider instead with the above recommended method
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Let's start with the simple one.

For the LEDs you will need resistors - 120Ω to 150Ω should be fine (R=V/I = (5 - 2.smiley-cool / 0.02).

As for the chip, all that does is convert the 0-5V of the arduino to the 0-3.3V that the display needs.  You can achieve the same result in a large number of ways, not all requiring a chip.

For low-speed communications resistors arranged in "potential dividers" can be used.  For higher speed you can use diodes, transistors, any number of methods.

I ended up not needing any resistors because the digital i/o pins have very controlled current so the LED did not blow or even raise in temperature... I just connected led to GND and digital pin 13 and that worked just fine. The led is 2.8 v with 20ma current... The arduino has a 3 v power supply too so I would think that works well with this led as well.
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You might find this video by Jeri Ellsworth helpful.



Have you thought about using a voltage divider if you're going from 5v to 3v3 in one direction?


This is the first time I am even working with LCD displays. Buffers, level shifters is all new term to me smiley-sad I am not entirely sure of which way to go about it other than pay x5 more for that chip online since I did not find it at that store and making these voltage divider stuff is sooo complicated....
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I am a little confused...

http://www.ladyada.net/products/nokia5110/#wiring

says you need a level shifter for a 5v microcontroller...Although arduino has a 5 V output pin there is also a 3V output pin...cant I just use that? I dont care about the backlight for now.
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idk why people said to use level shifter i found another tutorial that shows how to do it without any of that..

http://blog.stuartlewis.com/2011/02/12/scrolling-text-with-an-arduino-and-nokia-5110-screen/
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I am a little confused...

http://www.ladyada.net/products/nokia5110/#wiring

says you need a level shifter for a 5v microcontroller...Although arduino has a 5 V output pin there is also a 3V output pin...cant I just use that? I dont care about the backlight for now.

Are you not confusing I/O pins with power pins?
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okay guys. Thank you! I got home and ended up ordering that chip on ebay (Initially I didnt because I am short on time which is an issue when shipping is concerned) In the meantime I will build a voltage divider instead with the above recommended method

If you need chips on time, I have had good luck with Digikey.  They send you an email when they ship which is many times about an hour after you place your order.  They are that quick.  Most of the time, like 90% or so, I get it in 48 hours and that is with normal USPS first class which they charge about $4.50 in shipping for small orders of about 8 ounces or less.  This is for Minnesota to Illinois, you may be further away.  They will beat eBay sellers on shipping the vast majority of the time.  I can't recommend them highly enough, they have good prices too especially if you are ordering a decent amount and hit the first price break (usually 10-25 for ICs and 200-250 for passives, etc).
« Last Edit: September 18, 2012, 03:02:27 pm by JoeN » Logged

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I am a little confused...

http://www.ladyada.net/products/nokia5110/#wiring

says you need a level shifter for a 5v microcontroller...Although arduino has a 5 V output pin there is also a 3V output pin...cant I just use that? I dont care about the backlight for now.

Are you not confusing I/O pins with power pins?


i am not sure what i am confusing with what but i got it working!!! I didnt use a level shifter just plugged it in..

Dont know still why level shifter was needed since arduino has 3 v output power pin...Dont know what a 5v or 3v micro controller really means..





if I wanted to use the backlight it says to use a current limiting resistor. I am also told backlight operates on 5v so cant I just use 5v power pin from arduino for backlight and continue using the 3v power pin from arduino for the LCD text display?



I am not sure why I need a current limiting resistor unless my power supply voltage is exceeding the device's voltage requirement since I was told that "your device will only use as much current as it needs"
« Last Edit: September 18, 2012, 03:10:10 pm by twirap » Logged

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