Ask Slashdot: Hobbyist-Ready LCD Touch Panel For Embedded Projects? 142
michael_cain writes "I've been asked (by family, friends) to consider several small embedded controller projects. A good starting point for all of them would be a backlit LCD graphics module with touch screen pre-mounted in a plastic enclosure with enough room behind the display for a custom circuit board. 320-by-240 pixels, 3.5 to 4.5 inch diagonal measure, monochrome is sufficient (but color is always cool), easily driven by an AVR or PIC type microcontroller. And priced at a reasonable point for a hobbyist! Anyone seen anything like this?"
Largest I've found so far. (Score:4, Informative)
http://www.adafruit.com/products/376
2.8", touch screen, colour. /shrugs/
Gotta love marketing (Score:2)
'This TFT display is big (2.8" diagonal)'
At least they don't say "cheap" or "low cost"at 70 bucks.
Re:Largest I've found so far. (Score:4, Informative)
adafruit carries several kinds of screens in different sizes. They appear to be designed to work with cheaper cellphones. Refresh and io rates can be slow. You can either get the bare screens with plastic ribbon hanging on them or get them with a little controller board. Save yourself the headache and get one with a control board. Most of them include code to interface with Arduino and/or other hobby microcontrollers.
The data transfer rates on those i/o boards usually aren't fast enough to support video. On some of them you can actually watch it refresh, it's like unpacking a gif on a computer 15 years ago. So they work better for simple interfaces and displaying text (without scrolling) than for images. But you can draw icons as long as you don't get carried away.
The demo code is often not properly optimized either, so you can get more out of them if you are ready to roll up your sleeves and get to work on their "drivers". I was able to reduce full screen image render on one here from 2.8 seconds to 650ms by recoding the higher level io layer that was in the driver sketch. (didn't have to mess with the library)
I haven't used the touch interfaces yet, but it does add an additional level of complexity with the programming and with the io pin requirements on your controller. If you are going to be rendering icons or images, insist on one that has a sd card adapter built onto the io board, otherwise you are going to need to get one of those separately also to load the images from, which will further add to the cost, complexity, and io pin requirements.
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Re:Largest I've found so far. (Score:4, Informative)
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Not sure how "industrial" OP wants to go but we use these in all of our control panels - the prices are size dependent, but the smaller ones are well under $100, the larger ones can run upwards of $400. There are several other lines they offer if this one doesn't do what you need:
http://www.kinco.cn/category.aspx?NodeID=108 [kinco.cn]
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Do resistives need calibration? We have some capacitive ones used in our products and that's a severe irritation.
Resistive screens need calibration (Score:2)
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Too bad it's a resistive touch screen, capacitive would be much better.
A while ago someone said in /. that a capacitive touchscreen requires glass, glossy surface to function. Thus the possibility of making a matte screen would still speak for resistive ones. And, the accuracy with a stylus, as tepples said.
liquidware.com (Score:1)
android, beagle or arduino versions of what you need
Old smart phone (Score:3)
says it all
Re:Old smart phone (Score:5, Informative)
Yes, this is the way to go. Grab an older Android phone.
Fuck micro-controllers, just write an app. It's got wifi, bluetooth, ethernet (I assume that can be done over USB easily), haptic feedback...what else do you want on a hobby board?
Re:Old smart phone (Score:5, Insightful)
...what else do you want on a hobby board?
The pleasure of doing something yourself?
Hobbyists are more or less the same no matter their particular hobby.
In the remote control world, I've come across guys who could pay for whatever they wanted,
instead they spend their nights and weekends engineering designs and hand fabricating parts.
Haven't you ever heard the expression that the journey is as important as the destination?
Hobbyists (Score:1)
...what else do you want on a hobby board?
The pleasure of doing something yourself?
Yes, but there are reasonable limits to that if you're serious about the project.
To develop my own internet-accessible thermostat, irrigation system, house control, etc... I could put a $40 "hobbyist LCD" on an arduino and add another $40 for an ethernet shield. Or, I buy a 6" Linux ebook reader or a 7" under-powered -but already hacked- android tablet ($20 biglots or $50 bens-outlet) and put my arduino on the usb-port.
Not only can I focus on the part I really want to develop, it also makes future re
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Yes, this is the way to go. Grab an older Android phone.
Fuck micro-controllers, just write an app. It's got wifi, bluetooth, ethernet (I assume that can be done over USB easily), haptic feedback...what else do you want on a hobby board?
Yes the high level of a standard smart phone is very useful. Especially for human interface. And WiFi/BT/ENet/USB for communication with other high level devices.
However, how many user programmable I/O pins does it have? How man AD converters? What if you want to read temperature probes or other analog devices? Or interface with other low level devices? Sure you could design a custom USB device to do that, but now you've defeated the convenience of using a smart phone.
The hardware depends on the
Not recommended. (Score:5, Insightful)
There's a few issues with smartphone screens. Given enough effort you can make pretty much anything work, but here's what you'll be up against:
- Knowing what all the pinouts/connectors/voltages/signal levels are.
- Data format: Most of these screens require a proper graphics controller to drive them, capable of clocking RGB data out of a framebuffer into the panel at a pixel clock of several MHz. You might be able to do this with a PIC32, but your code will be blasting data at the panel 99% of the time. You're in the territory of ARM7/ARM9 processors with SDRAM hanging off them when you're making a bare RGB LCD panel work.
- Power: You'll likely have to generate a backlight voltage, and possibly even bias voltages for the LCD panel itself. The LCD may also run at a different voltage node (3.3V or less) while your AVR might end up being 5.0V.
- Touchscreen: Resistive touchscreen isn't too hard to manage. If it's a capacitive touchscreen you might be able to wire it up to an AVR and use their QTouch libraries to make it work. But I'll warn, prototyping a capacitive touch system can be an exercise in frustration - it's not bad when everything sits in one place on a PCB, but you can't breathe on an airwired capacitive touch system without screwing it up.
Honestly, you're best off finding a "smart LCD" with a built-in controller, with a simple SPI/UART/8-bit-parallel/etc interface. Adafruit has an Arduino compatible one up on their site which might be a good starting point, I'm sure there'll be plenty of other suggestions posted here.
Or hell, you're better off keeping the smartphone whole and finding a way to reprogram it to do what you want.
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Or hell, you're better off keeping the smartphone whole and finding a way to reprogram it to do what you want.
I think that's exactly what LanMan04 meant.
Or are you the type of person who takes apart old Pentium IV machines and tries to make a space heater out of it?
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I think that's exactly what LanMan04 meant.
Or are you the type of person who takes apart old Pentium IV machines and tries to make a space heater out of it?
You're right, why would one pull apart a Pentium IV machine to make a space heater when it's already a space heater?
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It might have been what LanMan04 meant, but it does sound like the person is more interested in the build process rather than the end result.
As such then if you recommend a device, it's probably going to be ripped apart and used for parts. Not that there is anything wrong with that.
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Or hell, you're better off keeping the smartphone whole and finding a way to reprogram it to do what you want.
Pretty sure this this exactly what was meant.
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Actually, there's an even better reason to stick with cheap Android tablets from China -- the market for LCDs in particular is *extremely* volatile. It's almost suicidal to design a product around a LCD screen you haven't already bought sufficient quantities of to build every unit you plan to build, because any given screen could become unavailable at any time without warning.
At least with Android tablets, you have a relatively stable programming environment. And if you really want to get down & dirty w
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Automotive forums? (Score:3)
Sounds like the kind of thing that people who build in-car systems would know about.
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In-car LCD systems are pretty overpriced really. For my upgrade of my system I've been considering figuring out how the iPad drives it's display and then adapting something like that.
Here's an Arduino (Score:5, Informative)
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MOD UP!
Nice find!
Description: SMART GPU
Intelligent Embedded Graphics Processor.
Price: $89.00 USD
-We ship Worldwide directly to your door!
Mikroe has them (no package) (Score:5, Informative)
SparkFun and eBay (Score:2)
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Adruino displays (Score:1)
Cheap Android Tablet (Score:3)
I've looked into something similar to use as a controller/receiver for a whole house audio system, and you may want to look at a cheap Android-based device, some of which can be had for less than $50. For that price you get a resistive touch screen at around 320x240, 8G storage, stereo output, 256M RAM, WiFi, USB and a Java-based OS with plenty of apps pre-built and a well established development community.
For a small 4" device, Google "benss android". I was able to find half a dozen listings for this under $50. (Haven't tried it, though.) Also, Big Lots in the US regularly sells 7" refurb tablets for $70.
- Stealth Dave
Amulet Technologies (Score:3, Informative)
Amulet Displays allow you to separate the UI (dedicated UI chip w/ display) from the execution and run it via an event driven framework. You can code it or it has a drag and drop version.
www.amulettechnologies.com
7 and 8 inchs sizes at LogicSupply (Score:4, Informative)
http://www.logicsupply.com/categories/touchscreen_displays [logicsupply.com]
They might be more expensive than you're looking for, but they have a nice selection.
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Re:7 and 8 inchs sizes at LogicSupply (Score:5, Informative)
These should give you some ideas
http://www.sparkfun.com/products/8977 [sparkfun.com]
http://www.sparkfun.com/products/10089 [sparkfun.com]
http://www.sparkfun.com/products/11075 [sparkfun.com]
http://www.sparkfun.com/categories/76 [sparkfun.com]
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Similarly, if you want HDMI in, just search Ebay for things like this: hdmi touch lcd monitor
They start around $150.
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Anglia Springboard (Score:1)
You want an Anglia PIC32 Springboard!
http://www.anglia-displays.com/evalBoards/evalBoards.asp
I have no connection to them except being a happy customer. We used their kit with a little 3.7" display to develop an industrial control device and the project went smooth as silk.
The examples they provide actually compile and work as-is (what a novelty), and the Microchip Graphics Library is as good as you'll get for free and doesn't have too many bugs while performing acceptably.
Easily driven? (Score:2)
If you want similar functionality with a mono or color big size LCD, you have to have something in the way between the AVR and the LCD itself that is going to retain a display memory so that the LCD can be continually refreshed (and don't try to do that with an AVR). You co
AdaFruit or SparkFun (Score:5, Informative)
Mimo capacitive touchscreens up to 10" (Score:1)
We embed these in our Atom-driven products to run GUIs and they work like a champ.
Mimo 7" USB touchscreen [mimomonitors.com] = $180
Mimo 10" USB touchscreen [mimomonitors.com] = $260
We use NT embedded but these also have OSX drivers, and if you want to use these with Unix you're not alone [freedesktop.org].
Mini2440 (Score:2)
Happy hacking! Jasper
The point? (Score:2)
Ok, not too hard to find touch LCD panels online, but I wonder just what is the point of this device you are attempting to make?
There are so many products in just about the size you are looking for I have to wonder why not either go with one of those products, either as the final device or a basis to create the device you want out of it?
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Ok, not too hard to find touch LCD panels online, but I wonder just what is the point of this device you are attempting to make?
I would imagine the point is the OP wants to build something him/herself.
There are so many products in just about the size you are looking for I have to wonder why not either go with one of those products, either as the final device or a basis to create the device you want out of it?
Well for one thing, building things has its own rewards. But also, a lot of times commerical products don't necessarily have the bells and whistles you want. The way I read the OP's post, he was already at the hobbiest electronics stage, and presumably wanted to advance beyond the simple blinky light stage. He/she wanted to know what was available in terms of displays.
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He/she wanted to know what was available in terms of displays.
It is easy enough to find general LCD touchscreens for hobbyists, that is just a google search away.
To be able to recommend the best one for the purpose one must know the purpose.
Once one knows the purpose you can either recommend them a specific part, or a complete device that could be cannibalized for not only the display, but many other internal parts that already work with the display.
The more information given the better answer he'll get, and he didn't give enough information imo.
.NET Gadgeteer? (Score:1)
Might be worth looking into, bit pricey compared to Arduino though.
But the starter kit comes with a mainboard and a 4" LCD touchscreen which is pretty decent for small projects. The hardware is largely made by GHI Electronics...
http://www.ghielectronics.com/catalog/product/297 [ghielectronics.com]
Not sure if this would be suitable or not...
Sparkfun (Score:5, Informative)
Sparkfun has lots of hobbyist-friendly parts, including LCDs: http://www.sparkfun.com/categories/76?sort_by=price_desc [sparkfun.com]
The only thing they're missing from your requirements is an enclosure, but certainly you can hack something together.
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Crystalfontz is nice (Score:1)
Earth LCD (Score:1)
http://store.earthlcd.com/
Ebay has a section for LCD for embedded devices. (Score:1)
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Looks like a larger PIC would be able to drive it given enough I/O pins or some extra glue logic. The supplied interface needs a 16 bit parallel plus a 4w SPI for the touch sensor (plus a few control lines). A bit of a shame they did not bring out the mode control lines as the display controller appears to support a SPI interface directly.
Also no built in ROM so you'll need some allocation for the character font you want to use.
Earth LCD Packages (Score:2)
Small LCDs in a variety of types and sizes with driver boards.
http://store.earthlcd.com/ [earthlcd.com]
MMS-e displays (Score:1)
HERE [mmselectronics.co.uk].
Lots of reasonably priced displays, some with touch and on-bard "intelligent" controllers.
Spend 110 bucks (Score:2)
DIY, Baby! (Score:2)
If you are tempted to go the DIY route, Community Core Vision [nuigroup.com] a good place to start.
Happeh hacking!
Freescale Tower System (Score:1)
http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=TWR-LCD&tid=m32TWR [freescale.com]
Lots of different stuff you can do with it. Hope that helps.
Rayslogic 3.5", 4.3", 320x240 LCD products (Score:1)
Missing the point (Score:5, Informative)
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I would check out used/cheap PNDs. You get a minimal enclosure with enough room for a pcb and battery (you might even reuse the battery and maybe the charging circuit if possible). I bet you can find some older ones with 3-or-so inch resistive screens for under 40 bucks - probably 10 at a garage sale. As long as the enclosue, screen and battery are ok (you may not even want the battery) it should be a safe bet.
Pawn shops (ahem) tend to have lots of these as well.
Granted you are just hoping you can gracefu
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Get a cheap Android tablet that has a USB host interface. Then attach all your relays and sensors via USB (or USB to serial, if need be).
Contact the mods (Score:2)
Ask them to update your entry with your clarification, that way every one will know, this post could get obscured
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Have you considered acrylic or Lucite? Possibly wood? Harbor Freight (US discount power tool chain) carries "good enough" routers for under $20, and a router + wood could make a very posh "luxury" facade for a touch screen... Polished screws with possibly non-standard heads in counter-sunk holes on the facade could be made to fit with the design aesthetic... you even see *fake* countersunk shiny screw heads on bezels of some devices, due to how it looks "high-end" in some contexts.
So, RV or boat control p
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Unfortunately the enclosure is hard. As hobbyists we have to frequently repurpose mass produced equipment. There are some things like circuit boards which can be made in small volumes economically, but displays and injection molded plastic enclosures have very high tooling costs, so you'd need to repurpose. In this case there's probably nothing premade that will meet your needs: small devices with touchscreens are almost universally designed to be hand-held, which means as small and light as possible. T
TFT 3.2" 320*240 With SD Touch Module (Score:1)
http://www.satistronics.com/tft-32-320240-with-sd-touch-module-arduino-compatible_p2888.html [satistronics.com]
or
http://www.sparkfun.com/ [sparkfun.com]
http://www.goodluckbuy.com/ [goodluckbuy.com]
An old android ebook rooted may be cheaper. (Score:1)
I built a cheapy 4 line lcd/arduino interface for my custom security system for around 60 bucks. It was butt ugly because good cases are hard to find or expensive to custom build. My wife HATED it. So I found a cheapy android (1.5) ebook with wifi and rooted it for about $90 (could probably find it for 60 now) and wrote an android app. It looks WAY better than my butt ugly lcd and is also going to be an interface to my weather station (when I get around to finishing it) and a fe
Chumby (Score:2)
You want a Chumby. Everything else lacks custom enclosures, or costs so much money you may as well buy a full PC.
Look on eBay (Score:3)
Search eBay - I bought a 3.2" LCD with touchscreen like this one [ebay.com.au] (~$25) and I'm currently working on driving it with an ARM Cortex-M3 controller.
The downside is that these ones are generally designed to interface with 8051 or 68000-type micros, hence they only expose the 16-bit parallel bus on the LCD controller. Not as optimal, but the displays are quite cheap.
OP has the wrong premise (Score:1)
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Your argument is like saying somebody shouldn't cook, because there's an abundance of restaurants and prepackaged, prepared food.
Some of us like designing hardware from components. We like designing circuits, laying out printed circuit boards (and fabricating them), component soldering - including things like toaster-oven reflow soldering. We like debugging wire protocols, using logic analyzers, and yes, programming microcontrollers.
Being able to say "yes, I can design products that use a touch screen" can
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When you want to design an build a house, you don't start out by designing and building a car to park in the garage.
That's not even an analogy: The car isn't even part of the house. It can be removed or omitted, and doesn't change the properties or functionality of the house at all.
To use your house analogy, a touch screen would be like designing the roof for the house. Rip out the roof, and the house isn't a house anymore.
I don't really understand why you can't understand this: A touchscreen is just another part - just like a resistor, capacitor, switch, inductor, LED, etc. Nearly all electronics work involves connecti
4dsystems (Score:2)
Try looking at http://www.4dsystems.com.au/ [4dsystems.com.au]
They sell touchscreens around that size with a controller that you can either program using a C-like language, or send commands to from an AVR etc.
Technologic Systems (Score:2)
It's bigger than you wanted and not cheap but it does have an enclosure. It runs Linux. Boots really fast. Lots of I/O options.
http://www.embeddedarm.com/products/board-detail.php?product=TS-TPC-7390 [embeddedarm.com]
You can also try Crystalfontz. They make lots of displays. Even OLEDs.
Old cell phones (Score:2)
use an old Palm handheld? (Score:2)
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Dunno, without knowing exactly what his planned use is, odds are a COTS solution is something to consider. A cheap tablet or phone that can be hacked to get a bit of I/O or that has USB host mode support just might be the fastest and cheapest way to solve the problem. After all he wants a bitmapped touchscreen and driving that is outside what I'd want to be doing on most AVRs, especially ones available in DIP packages.
Re:yes (Score:5, Funny)
What the fuck is it with people suggesting "get a Tablet" to almost every single question that comes up these days?
"My car has trouble starting in the mornings..."
"Get a tablet!"
"My pool filter seems not to be doing it's job very well lately..."
"Dude, tablet!!"
"What's the best product to get stains out of concrete?"
"TABLET!!!!!!!!!!!"
Tablets are great for some applications, but not every application that involves tech in any way, shape, or form.
Re:yes (Score:5, Funny)
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I hear Apple is already at work on the iPad 12, and it will come with an app to make decaf lattes... and another that will make your cat's liter box smell like African Violets...
my doctor loves tablets (Score:4, Funny)
he gives them to me for almost everything I've got.
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Get a tablet. Preferably a tranquilizar tablet.
Run a spell-check before submitting. Preferably an English spell-check.
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"I don't know how you'll make sure my lawn waters regularly (hint: mechanical timer), my lights turn on at dusk and off at dawn (hint: opto-electric switch),"
Mechanical = things to break. My digital Toro sprinkler box is just fine, TYVM.
Also, photo-switches? Please. Those things get even a decent full moon and they don't go, or if they do go and you're running HID, you blow the ballast or bulb (that's what's happening at my store right now, in fact.) THOSE you put on timed circuits as well.
Your own solution
can't tell if you're serious (Score:2)
A digital sprinker box is still going to have mechanical parts in it.
Putting lights on a simple timer would be messed up around here--depending on time of year the length of the day varies from 5 hrs to 17 hrs. The proper solution for lights is a photosensor with averaging and hysteresis.
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"A digital sprinker box is still going to have mechanical parts in it."
There are NO mechanical parts in my Toro box. ZERO. Anything near mechanical is at the water lines, roughly 75 feet away from anything that resembles a control box.
Timers can be adjusted, you know. You can even get some that will let you set individual days based on expected length of daylight. They're in use in horticultural systems ALL THE TIME.
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Offtopic: If you have a MECHANICAL lawn timer, it is very old. I installed automatic lawn sprinklers all through college in the summer, in the 90s, and it was all digital control e
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Greetings and Salutations;
While you have a point here, this is a bit of a harsh evaluation, especially since we do not have any information on the projects the OP speaks of. I can think of half a dozen places in Home Automation, for example, where a small, cheap, embedded controller, with a touch screen, would be a great answer.
While the solutions you propose are, in general, quite workable, what they lack is flexibility. For example, a mechanical timer WILL spray water at the same time, for the same
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Yeah the question didn't make much sense. "I've been asked (by family, friends) to consider several small embedded controller projects." --- Why are they asking you for embedded projects? Are they bored? Or is there some other goal they want to achieve? It's unclear.
If the mission is to learn programming, I'd hand them a copy of BASIC for their computer, and have at it.
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If the mission is to learn programming, I'd hand them a copy of BASIC for their computer, and have at it.
Hmm. I don't understand why you'd want to sabotage their mission by handing them BASIC though. :-(
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I think you're biased towards being a bit dumb.
Currently, touch screens are a bit pricey, and can be a bit messy to work with. Though it's less awesome, a serial lcd backpack with a few buttons can be had for 20$ or less. That being said, some of the off brand chumby clones might work well for getting a touch s
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Hi anonymous-E, you write:
"I didn't see a question in the original post"
At the top of the page, see the squiggly thing on the right side:
"Ask Slashdot: Hobbyist-Ready LCD Touch Panel For Embedded Projects?"
You add:
"asking you to display your arrogance... troll much? need a hug?
It's not arrogance to point out the OP has a bias toward both embedded systems and touch-screens.
It's not even trolling to suggest to him [and other posters] that there are other methods of SOLVING PROBLEMS
but step one is to identify
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It's not arrogance to point out the OP has a bias toward both embedded systems and touch-screens. It's not even trolling to suggest to him [and other posters] that there are other methods of SOLVING PROBLEMS but step one is to identify said PROBLEMS and step two is to work on SOLUTIONS. One doesn't start from "hey um er uh like yeah which touch-screen should I use with my embedded system answer to everything that my family and friends [please don't let me die of laughter] asked me to solve"
Has it occurred to you that OP's friends/family have asked him specifically to consider embedded systems? He says so right up there at the top of the page. It's also entirely possible/probable that he's already discussed potential solutions with his friends/family and they determined that embedded systems with touchscreens are the best solution, and all he's asking for is actual product suggestions? That's what I'm getting out of the question, and it seems that most of the others in this thread also got tha
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You make a good point, Keith.
I'll try and keep _my_ bias out of it going forward.
Lesson learned.
Thanks, brother.
E