SPI or I2C interfaced LCD module recomendations

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Does anyone have any recommendations for a reasonably priced (<$25 US @ qty. 100) LCD module with a SPI or I2C interface? I have found plenty of UART interfaced modules, but my UART is already in use an I would prefer not to implement a software UART. A 16x2 character module is prefered. Thank you in advance.

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Not sure about the price range or SPI compatibility, but check out what CrystalFontz website has. They have several kind of interfaces as I recall. Sunlike also does LCDs, but I am pretty sure they were only HD44780 compatibles.

Also Newhaven and Itron/Noritake make VFDs which some of them have both HD44780 and SPI interfaces.

But if you are not afraid of interfacing directly to HD44780 compatible bus with other IO bus pins, do it. There are also plenty schematics on the net how to interface the SPI to HD44780 bus with 1 or 2 simple discrete shift register chips.

- Jani

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Jepael wrote:
Not sure about the price range or SPI compatibility, but check out what CrystalFontz website has. They have several kind of interfaces as I recall. Sunlike also does LCDs, but I am pretty sure they were only HD44780 compatibles.

Also Newhaven and Itron/Noritake make VFDs which some of them have both HD44780 and SPI interfaces.

But if you are not afraid of interfacing directly to HD44780 compatible bus with other IO bus pins, do it. There are also plenty schematics on the net how to interface the SPI to HD44780 bus with 1 or 2 simple discrete shift register chips.

- Jani

Thanks for the quick reply. I'm trying to minimise the number of components used, so the shift register idea will be put aside for now, but i'll keep it in mind if i can't find anything that fits my requirements exactly.

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And you dont want to use the regular old 4 data bit 6 wire interface because??

Imagecraft compiler user

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Hi,

look at www.lcd-module.de maybe there you find what you are looking for....

Klaus
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Look at: www.megausb.de (German)
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@bobgardner
The project I am working on Is a mega48 which already has a radio module (uart +2 control lines) and a 4x5 keypad (9 lines for the matrix + 1 interrupt line) Which leaves just 6 lines to use(I really hate using all my I/O lines up at the start of a project....no room to grow).

@ everyone
Thanks for all your sugestions. A lot of the manufacturers you have mentioned didn't show up on my first search.

*** Edited to hide terible spelling ***

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If the LCD is going to be nearby, I'd probably use external shift registers for the keypad and hook the LCD up in a conventional manner.

Even though the chips (shift registers) mentioned are inexpensive, spending the extra buck for an AVR with more I/O pins may end up to be more economical in terms of total project cost unless volumes are high.

Lee

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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Well, Optrex have some graphical LCD that can be controlled by SPI plus 2 lines... But I would follow Lee/theusch suggestions, since it's the way I would do it.

Guillem.

Guillem.
"Common sense is the least common of the senses" Anonymous.

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@Lee & Jani
Due to the cost of the serial LCDs that I have found so far, I think i'm going to go with shift registers either on the keypad or LCD. Thanks for all your help.

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Iyachtu,

OK, call this an odd-ball idea but when I got tight on IO pins on an AVR project, to free some up, I switched 5 individual button pins to be a single switched resistor network into just one ADC pin and hence freed 4 pins for the cost of a handful of resistors. While it would be more complicated to do this with 20 button keypad it might still be "do-able" though you may face problems if you are hoping to spot combinations of buttons being pressed at once. But given that the ADC has a range of 1024 values and you have 20 buttons to sense, each one should be able to be made to fall into a range of about ~50 ADC readings which should space them far enough apart to distinguish them and still allow for a bit of inaccuracy - or maybe 10 buttons each on two ADC pins? 'course the requirement for the button press to be detected and cause an INT will still require a bit of thought but perhaps timed polling of the ADC might be enough to catch button presses? (this is what I do)

Cliff

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I vote for putting an LS165 on the keypad inputs, and maybe a LS138 on the outputs. Two cheep chips, and saves several IO pins, not much more complicated to program.

Imagecraft compiler user

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Here's some LCDs that have SPI, I2C, or RS232 interface, selected by soldering a resistor on the back.
http://www.newhavendisplay.com/i...

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Iyachtu wrote:
@Lee & Jani
Due to the cost of the serial LCDs that I have found so far, I think i'm going to go with shift registers either on the keypad or LCD. Thanks for all your help.
One 8 bit shift register will drive 4 lines of the keypad and 4 data lines of the display in 4 bit mode for a savings of 6 pins.

Note to Bob: Back in the day, the 'LS138 was my favorite chip. Ain't seen one in a while.

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The EA-DOG LCD's from by Electronic Assembly work well at about $12 from Mouser. I am using one in SPI mode in a current project I am doing.

--john

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Ah the necromancer cometh eh? - did anyone spot that shift in the space-time continuum ?

(y'all are answering a 2.5+ year old thread)

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Ahhh -- So it is. I wonder if the OP has found one yet ?

Could be useful anyway. Maybe there are new devices available now that wasn't available 2 years ago.