stm32f429Idiscovery demo touchscreen bug

[atsju2]

Posted on December 04, 2013 at 20:29

Hello,

Today I bought one of  these new stm32f429 discovery boards :

http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/PF259090

For the moment I only launched the demo software, but it seems that the tuchscreen is abnormally inaccurate (less precise than the one of my colleage). For example in the calendar, when my pen is on the 22 of the month, the red square moves between the 18 ant the 21.Has someone experienced the same problem ? Is there a way to callibrate the touchscreen ?Some pins were creased when I got the board, could a shock during transport have killed  the touchscrean ? (In this case I will try to exchange the board) #stm32f4 #discovery #stm32f429

[Tesla DeLorean]

Posted on December 04, 2013 at 20:44

Beyond removing the protective film, I can only observe that the screens themselves don't transit very well, and neither of the units I got shipped survived the trip. I have two from a seminar event that work Ok, but several people had defective units there too.

Firmware source isn't currently available, but has been promised soon.

[atsju2]

Posted on December 04, 2013 at 21:14

So the problem is software and could eventually be fixed with a future upgrade. Do I understand well ?

Should I return the board to get an other one or wait for an upgrade ?

[atsju2]

Posted on December 04, 2013 at 21:18

[Tesla DeLorean]

Posted on December 04, 2013 at 21:42

I don't work for ST, you'll have to make your own decisions.

The resistive screen strikes me as something that can be addressed by calibration, I don't have access to the software so can't speak to how it does, or might be made, to function. If the LCD panel itself is working, I'd probably not bother to try and exchange it unless someone had a box of devices they could show me working better, and could hand one to me. As for the software load, it hasn't been released in source format, so you're on the same ship as everyone else. May be you can look over the STM32F429I-DISCO firmware library and see if there are any examples on how the touch portion works.

[atsju2]

Posted on December 05, 2013 at 06:53

Thank you for your answer, I will search in the code (but even if I find some calibration, I will not be able to recompile the code for the moment due to the 32K code limitation) 

[xacc]

Posted on December 05, 2013 at 12:15

My board is warped too, and due to that the screen is not flush and is loose on the one side. Not a big issue for me though. No bent pins either.

Also, what firmware/software are you referring to? The source code for the demo is included zip for the board.

[atsju2]

Posted on December 05, 2013 at 13:24

I refer to the demo software on the board when it's new (1.0.0rc3).

For what I have seen, this source code :  

http://www.st.com/web/catalog/tools/FM116/SC959/SS1532/PF259090#

is not exactly the same as the one in the card (for example, there are some differences in the order of the tests when you start with user buttun pressed). I don't konw if it's only minor differences

[warcatz]

Posted on December 05, 2013 at 19:54

Here are some library for the new st429 disco.

http://mikrocontroller.bplaced.net/wordpress/?page_id=2736

This guy made a good work with this library and demo's. The one you need is the #15

http://mikrocontroller.bplaced.net/wordpress/?page_id=2877

Cheers.

[Mark Edwards]

Posted on December 06, 2013 at 02:14

I don’t  use the touchscreen on my 429 Discovery boards and have only had the a brief look at what they can do.

But, from past experience of working with resistive touchscreen’s, calibration is done by changing the biasing resistors not through software (and resistive touchscreens are nowhere near as accurate as capacitive ones, in my experience). The creases you mention may well affect the accuracy if the trackwork of the flexible lead is damaged, so if compared to your friend’s board yours is highly inaccurate then perhaps you should get a replacement.