Capacitive touchscreen compatible with Olinuxino A13

Started by a+b+c, May 19, 2014, 03:18:28 PM

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Hi, I would like to ask you if anybody here have a experience with connecting a capacitive touchscreen layer to the Olinuxino 7" LCD display (A13-LCD7).

If you could post here a link to the compatible capacitive touchscreens and where to buy them, that would be great and I hope that many other users of Olinuxino would appreciate.

Thank you


I have not found a separate touch screen that would be a drop in for the 7" but I have found a Touch Revolution 7" cap touch panel complete with a very nice higher brightness display that works with the A20 so should work with the A13 as long as you have I2C bus access for the touch driver. It is higher cost (as are most cap touch displays in small volumes) but it is very nice and the display is much brighter.

I designed a custom PCB for the LCD that brings out the control signals to the same 40 way connector so LCD wise it's almost drop in but there is a small change to the config file for the timing.

As for the touch, this is done via I2C so it needs an extra connector and there is both Linux and Android source for this. I used the UEXT connection for this.


Thank you for your post Dave. Is there necessary any converter for I2C to UEXT connection? If so where is it possible to purchase it?
Is it this display which are you using?

Any chance that you would share your PCB?  :)

Thank you


Hi, I can't share the PCB itself as I am using this for a commercial project but I am willing to share the schematic and you can make your own board in Eagle or any other PCB software.

I'd offer to sell the boards but I am based in Indonesia and shipping costs are generally quite high from here and most people don't want to pay for it. :)

You can download it here. There is the schematic and there is a bill of materials and I have included a PCB layout drawing showing the placement I used. My board is 4 layer but you can get away with 2 if you want to.


Thank you very much Dave, I really appreciate it  :)

Anyway, I did some search online and found this capacitive touch panel

It seems to have the same port for the touch as Olimex's panels and also it does have a controller onboard. Do you think it might be working with the Olimex LCD's?

Thank you


No, it's not compatible with the Olimex touch connector. Olimex uses an ADC to interface the 4 wire resistive interface.

That panel you found is I2C interface, as is most cap panels. You'll need a new PCB to interface this to the Olimex and have an I2C interface available.

This is the IC for that panel.

Also, consider that this panel has no dimensions so you could be wasting your money if the cutout area is not the same.

Lastly. I couldn't find any drivers for this cap touch controller. That means work writing your own.


I just got an email about this panel tonight.

It should work with the A13, A20 etc. It will need a custom PCB to get it working but there is no reason it should not work.

The only downside is that it is only 200 cd/m2 and the Touch Revolution one I am currently using is 350 cd/m2 which is a lot brighter. If your units are always used in areas where higher brightness is not an issue, the lower price would make it more affordable.

They do have a 280 cd/m2 but with lower viewing angles and lower price.