Interfacing with Touchscreen LCD

[baberjaved]

Anyone gots information on how can I interface a PIC to a Touchscreen LCD (Resistive or capacitive I dun know the difference.. explanation?)
Is it really hard and a complex procedure or easy enough as interfacing an mmc card?

 

[Ambient]

I imagine you will need to find a touch screen to work with first. The data sheet for it will give you all the code you need.

 

[Sceadwian]

Resistive touch screens are pretty easy to interface with, There are four nodes, you apply a voltage to two specific nodes and read from either one of the remaining two which forms a voltage dividier giving you an analog voltage of the position on screen. You do this twice energizing different nodes and reading from the third to get either the X or Y axis. Capacitvie touch screens are much more complicated and I don't think it's practical to do it with a PIC directly, you're likley going to need a specific Ic for it.

 

[flemmard]

Resistive touch screens are pretty easy to interface with, There are four nodes, you apply a voltage to two specific nodes and read from either one of the remaining two which forms a voltage dividier giving you an analog voltage of the position on screen. You do this twice energizing different nodes and reading from the third to get either the X or Y axis. Capacitvie touch screens are much more complicated and I don't think it's practical to do it with a PIC directly, you're likley going to need a specific Ic for it.

How much is the cost of touchscreen LCD? How do I program for my actions?
Any SDKs?

 

[simrantogether]

Well..

Hi,

that's good if you are attempting things like this...

but i suggest you to go step by step..

step 1: read this.. https://en.wikipedia.org/wiki/Touchscreen

step 2: read application notes of microchip or anything you prefer..

Regards,

Simran..

 

[Sceadwian]

Check out Sparkfun electronics, I thought I saw an LCD module that has a resistive touch screen. The touch screens can actually be added to just about anything, it's just a clear sheet. Again I'm not much help there though as I have no idea where to get just the plain sheeting.

 

[Tim_B]

Have a look at this https://www.sfcompiler.co.uk/wiki/pmwiki.php?n=SwordfishUser.TouchScreen

 

[firewater]

Very good link Tim B, thanks

baberjaved, you didn't say what size you're looking for or your budget but if you want a built in library then Comblock makes one that uses basic.They start at $359 US and have forums for help.
Touch screen in five minites:
https://cubloc.com/phpBB2/viewtopic.php?t=465&sid=810d93a72a5b089e2c55c1b241df9530

https://www.comfiletech.com/index.asp?PageAction=VIEWCATS&Category=14

Crystalfontz makes a grey scale 320x240 4-wire resistive touchscreen for $122 US. It has a built in Epson S1D13700 controller with 32 KB of SRAM.They also have forums for your questions.MicroTips also has a 320 X 240 blue or blue/green backlit for $73.50 https://www.mouser.com/search/refine.aspx?Ntt=668-NG-F32240BFWNEB+ Texas instruments controller chip for $3.65 https://www.mouser.com/search/refine.aspx?Ntt=595-ADS7843E


Crystalfontz:Model CFAG320240CX

https://www.crystalfontz.com/products/320240cx/index.html#CFAG320240CXTFHTTS