"Resistive" touchscreens are the type you're most likely to use in a DIY microcontroller project. These consist of two screen layers coated with a resistive material and separated by a small gap. When touched, the layers make contact, creating a voltage divider circuit. The resulting voltage is easily measured and correlated to position. The top layer of the touchscreen is just a clear overlay, though; what really makes it work is the layer underneath. Approaches to implementing a screen range from putting a printed sheet behind a touchscreen for a static touch interface—actually a fairly simple method to pull off—to something as full-featured as an LCD smartphone display. Here are the three main options.
For flexibility in your choice of interface, buy just the screen. Nintendo DS Lite touchscreens are easy to use, and available for less than $10 from sites such as Adafruit and Sparkfun, but they leave the underlying layer up to you.
For ease of use, pick a screen and display combination such as the one from Adafruit ($40). It's fairly inexpensive but could tax your microcontroller, since it has to manage the graphics in addition to whatever else it does in the project.
For a more sophisticated interface, use a screen and display combination with its own processor, which reduces the load on the project's main microcontroller. Many sub-$200 options exist, such as Liquidware's TouchShields (about $140 at Liquidware)
hey vin, can you update the post with the following?
"For flexibility in your choice of interface, buy just the screen. Nintendo DS Lite touchscreens are easy to use, and available for less than $10 from sites such as Adafruit... but they leave the underlying layer up to you."
the adafruit touch screen comes with a full open source arduino library that does X Y and pressure detection so you don't have to write any code to get started!
@pt Hey - Yeah, perhaps the column could have been a bit more clear - when I refer to the underlying "layer" - I'm saying that using a Nintendo DS screen alone gives you the option of putting whatever physical layer you want under it - LCD, a TV screen, a drawing, etc... - not referring to the software layer - if that's what you were getting at.
That Adafruit LCD+touch screen I used, the tutorial linked to under the Resources heading, and the Touch Screen Library are incredibly useful. Absolutely one of if not the best way to get started right out of the gate with touchscreens. The tutorial has instructions for wiring the screen, an introduction to the touch screen and the graphics libraries, and some great demos. Anyone who reads this column and wants to get started with touch screens would do well to start there.
HI i love this idea. but i was wondering if anybody can help me.
I would like to turn a blackberry 9800 or other models screen and digitizers in to a touchscreen DIY.
i have access to them and i dont know how to hook them up to use to make projects from.
please if any body has any info on doing this. please email me at: email@example.com
Commented before Bubba, thats a surprise!
Think they will ever sell iphone screens seperatly? That would be awesome.
I wonder if this technology could be adapted the front dash of cars and you can change you air conditioning, heat, radio and other devices in your car?
The front dash of the car can be more smooth and also making the dash easier to keep clean. It seems all those little curves, crack, wrinkles and knobs and things all collect dust.
It maybe a new interesting style for the dash of a car.
Touch screens are nice but i don't understand the obsession, specifically for using them in cellphones. I honestly like qwerty button phones much more than touch screen phones and I avoid purchasing anything with an exclusive touch screen. Why is the touch screen replacing button + display interfaces for almost all cell phones except maybe blackberry? Their intended use was never an issue before everyone wanted to browse the internet while commuting. My province banned the use of cellphones while driving a vehicle about a year or two ago and I bet touch screens were the sole reason behind the ban
@Infusion inattentional blindness would be the reason they banned phones. It's when you actually look at something but your brain doesnt register it because it is busy multitasking.
I prefer buttons over the touchscreen besides on the iPad. But touch screens are bright and have flashy colors and that attracts "children".
Digital will phase out every mechanical thing possible
@bubba good idea, maybe next time you will come up with the idea of using an electrical current applied to a motor to roll up your windows
@BubbaGump. It's a pretty interesting idea, but it's totally unnecessary. I belive it would be something like the "Eggies" they're advertising currently. It's a good solution to something that wasn't really a problem to start with.
@Infinion. The law is the same in my area, though personally, I disagree with it. People who are doing it now, attempt to hide it somewhere near thier hips, causing more wrecks than before. It's my personal belief that if someone wants to do something, no amount of laws or bans are going to stop them.
A touch screen in a car would be very distracting to the driver.
@Jupiter1987. Sir, if a design that can be made that makes using the radio easy, air-condition, and more... yes, its a new thing and engineering would have to be done.. But I agree with you. I do not want to add distraction, but I do want to add convenience...
"I do not want to add distraction"
Too late for that.
My point was that many luxury cars made in the last couple years have these available. Many people have custom dashboards with iPads installed
Very cool PopSci. You sold me on this!
can anyone tell me some ideas to use with this?
OK, I went through all 11 'pages' of DIY and the 'Archives', looking for a DIY Wind powered generator/alternator to power my home. Any help would be appreciated. Schlah at G mail.
Heh, cool, I never knew I could do this quite so easily!