
An award-winning LCD with an Arduino built-in (using only 2 pins) - leonvonblut
http://blog.arduino.cc/2014/01/30/an-award-winning-lcd/
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tedivm
I know people are saying this is a bit steeply prices, but I think this is
perfect. I've been looking at the various options and they typically all
require three components- the touchscreen/lcd itself, a controller board of
some sort, and then the Arduino itself. Then you have to actually put it all
together, and as people have mentioned you end up with a lot more than two
pins being used.

This one at Adafruit costs $40, uses five or six pins, is smaller and doesn't
have the Arduino built in.

~~~
joezydeco
It's a nice project. I've purchased stuff from EarthLCD before and they're a
good group. Those complaining about the price probably have never tried
tooling their own kapton/copper flex circuit.

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hcarvalhoalves
On a side note, I like how the product is presented by two young girls. Is
this intended for educational purposes?

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poooria
I can't tell whether you're being a feminazi or just a creep. Either way, stop
it.

~~~
rurounijones
(S)He is pointing out that the presentation is done by two people who are
usually not associated with technology and development (they are young and
female) as a positive example.

He then posits that this is to show the educational possibilities.

Any negative connotations are coming from your mind, not theirs.

~~~
lifeisstillgood
Agreed, it's clearly scripted but when she moves onto presenting the project
you can tell she actually built it or has the understanding of a maker

I love that the target audience is advertising the product.

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ama729
> 320 x 240 Resolution

Aside from the fact that's for an arduino, which probably mean very low power
available, does anybody knows why all those hobbyist LCD are so low in term of
resolution?

It seem impossible to find something higher than VGA on mouser or even
Alibaba, much less a reasonably priced HD screen. Where are all those glorious
smartphone screen?

(I'm talking about small screen, but even larger one are not that much better)

~~~
lgeek
Well, you'll find the glorious smartphone screens are sold as replacement
screens for smartphones.

But of course, smartphones tend to have an LCD controller on the SoC, so you
just get a raw LCD parallel interface. That means the LCD has a tiny connector
with dozens of wires. Hobbyists are often enough scared of soldering SMD
parts, they won't try to solder that .4mm pitch connector.

Then you realise that even for 800x600 @ 60Hz you need a pixel clock of around
36 MHz, so you probably need a hardware controller, you can't really get away
with DMA and/or bit banging. Since you have an external controller, you can't
do any of the memory efficient drawing like Nintendo NES or sifteo[0], so
you'll need external buffer memory, probably at least 2 MB to fit two (16 bit
colour) frames for double buffering.

As the resolution grows, pixel clock frequency and memory size requirements
grow quite quickly. Soon enough you get limited by the bandwidth between your
MCU and controller, by limitations of parallel interfaces and have to switch
to LVDS and so on.

Most of these issues become much less relevant if a (even small) company wants
to design, manufacture and sell something like this. But I'm not sure there's
a demand. For most projects a small screen (with a controller chip and
available for cheap because it was designed and manufactured at scale for
older phones) works well enough (and you can get away with using a wimpy 8 bit
MCU). If you need a larger screen, it's probably cheaper to get a low cost
single board computer and a computer monitor. Economies of scale and all that.

[0] [https://www.adafruit.com/blog/2012/12/05/how-we-built-a-
supe...](https://www.adafruit.com/blog/2012/12/05/how-we-built-a-super-
nintendo-out-of-a-wireless-keyboard-sifteo-sifteo)

~~~
ama729
Thanks for the explanation.

That's something I wondered, taking a smartphone screen, but it seem pretty
daunting, indeed. Such a shame in a way.

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dirktheman
It looks cool, but the price is a bit steep. You can get a touchscreen LCD
from Adafruit at $39.95
([http://www.adafruit.com/products/1651](http://www.adafruit.com/products/1651)).
You still need to buy an Arduino, but they're cheaper than $45,-. I've bought
Chinese Uno V2's for less than $15 a piece.

~~~
amckenna
The advantage of their integrated LCD and Arduino is that it would only use 2
pins instead of the 6-7 that would be occupied by the shield you linked. This
would allow you to connect other shields and have more room for add-ons. I
agree that $89 is steep though, hopefully that price can come down as more are
made.

~~~
jpwright
I don't understand how this board only "uses 2 pins". The schematic shows the
ezLCD component still uses 7 pins for I/O. Using the SPI bus requires 4 pins
and the other 3 are presumably for the touchscreen sensing. The board still
has the full Uno footprint, so you could connect other stuff to those pins at
the same time, but you couldn't do anything with them while driving the LCD.

~~~
userbinator
Dallas 1-wire? Haven't looked at the schematic or anything else, but that's an
example of an interface that just requires 2 connections - signal and ground.

~~~
jpwright
That's not what this uses.

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StavrosK
Okay, how do they run that color picker sketch with only 2 KB of RAM available
on the Uno? I tried to do some _string parsing_ and it failed at 200 byte-long
strings due to lack of memory, how can they show an entire picture composed of
thousands of pixels?

~~~
Timmmmbob
Could be a more powerful ARM Cortex, rather than the insanely out-dated Atmel
chips. If anyone ever makes a 5V ARM processor Atmel will be finished.

Also I'm going to rant about Arduino for a bit: Yes it's very simple and easy
to get started with, but their API documentation is bad, and the IDE is
objectively and irreparably _awful_ and has not really improved since it was
first released. Making things even worse they don't provide a decent way to
integrate it into other IDEs because lots of the build logic is tied up in the
IDE.

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lgeek
I'm all for supporting small business that create hardware, especially open
source (heck, I'm working on some stuff myself), but they must make an effort
to make their products affordable. I can buy a 3.2" touchscreen LCD for $12 in
single quantities[0], shipped locally in the UK. The BOM for an Arduino is
somewhere around $10 in single quantities. Their selling point about only
using 2 pins? Yeah, shift registers or i2c I/O expanders are _so_ fancy...

[0] [http://www.ebay.co.uk/itm/3-2-TFT-LCD-Display-Module-
Touch-P...](http://www.ebay.co.uk/itm/3-2-TFT-LCD-Display-Module-Touch-Panel-
Screen-PCB-
Adapter-240-x-320-Pixels-/331106884444?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item4d17821b5c)

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kvzivn
Does anyone have any idea of what it will cost? I can't wait to get my hands
on one of these.

~~~
deserted
It's a bit steep at $89.

[http://earthmake.com/product/arlcd/](http://earthmake.com/product/arlcd/)

