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Beep printing 7 char string

Posted: Mon Oct 20, 2014 9:55 pm
by grnbriar
Hi,
I'm a new user of the GTT50. So far things have gone pretty well. I had no issues hooking it up to a atmega1284 (I have ttl serial version).
And have been able to draw my interface and receive coordinate touch info back. So it's all up and running.

Today I was trying to finish up by adding a custom start screen and custom ttf font. (I had been just using the default print characters with no command since there is no default font otherwise.)
I was able to get both the startup screen and the font deployed and working and then ran into a very odd problem.

Though in my setup I tell it to turn off tactile and beep feedback, any time I send the print utf8 string command with a string that has exactly 7 characters, I get a beep.
ex - 254 37 0 7 Patches

Since this is a musical device I have to turn that off.
Is this an odd bug?
How do I disable it, or disable the piezo speaker permanantly?
This is the only issue I've had so far.

Otherwise, I would just like to ask when the 7 inch GTT will be available, or is it already directly available from Matrix?
No one has any. I bought the 5 inch for testing, but it is working fine and I plan to use a 7" if possible.

Thanks,
David

Re: Beep printing 7 char string

Posted: Tue Oct 21, 2014 9:00 am
by Raquel
Hi David,

Thank you for posting in the forum.

It is good to hear that things are working well for you and the GTT50A.
I am sorry but I see that there is an error in the GTT50A manual. The command 254 37 Print UTF-8 string does not take Length (short) parameter.
You may simply send the UTF-8 sting after the command 254 37 and make sure the string is null terminated.

For your exactly 7 character UTF-8 commands such as 254 37 0 7 Patches:
What is happening is that command 37 ends as soon as it saw 0 (null) and then took "7 Patches"
7 is ASCII bell character which is the reason for the beep. I imagine 'Patches' then shows up on the screen as data to display.
You should be able to just send: 254 37 Patches 0

I will inform our technical writer and get the manual corrected.
Thank you very much and sorry for the inconvenience.

By the way, to answer your question regarding 7" display, yes we do sell the GTT70A's. Please check this out.

Best Regards,

Re: Beep printing 7 char string

Posted: Tue Oct 21, 2014 9:27 am
by grnbriar
Thank you very much for a quick fix to my issue.
I had noticed that a lot of other commands with strings just used null termination.
Would this also apply to any other commands where the manual shows a length? Are all commands with strings null terminated rather than length?

Other than this, the documentation has allowed me to figure out every thing I needed to do.
The last thing I need to try is to turn on Manual Update when I redraw entire pages, so you can't see the controls draw and then run with it off so sliders will redraw live.

Thank you,
David

Re: Beep printing 7 char string

Posted: Tue Oct 21, 2014 10:02 am
by Raquel
Hi David,

Yes, mostly when strings are involved, null is the end marker hence no need for a length parameter.
But there are commands that still need length parameter, eg. command 254 36 - Print Unicode String (as 0 can show up at any point in the string).

Good to hear things are working. It sounds like you have a very good handle on display commands and features.
If you run into any troubles please do not hesitate to post in the forum.

Thank you,

Re: Beep printing 7 char string

Posted: Tue Oct 21, 2014 7:12 pm
by grnbriar
With the manual update working (and all my string printing correct now), the first section of my gui is running and complete.

One last question - I would like to make sure that the 70 - 7" and the 5" are identical software wise?
I just copy my files to the SD, plug in and go?
I would like to be able to use the same gui code on two different models with different screen sizes.
Just would like to know if they truly share an identical command set.
And is the same true for the smallest GTT model, the 3.5? (The 4.3 is too close in price to the 5 to help for this project - size isn't an issue.)
Not planning on using it, but would like to know for reference.

And from a greyed out pulldown entry, you have a 10" in the works?

Thanks,
David

Re: Beep printing 7 char string

Posted: Wed Oct 22, 2014 4:43 pm
by Clark
Hello David,

Good to hear your code is up and running, we have taken care to use the same code base for all units in our GTT Rev 2.0 line. You can communicate to a GTT70A, GTT50A, or GTT35A in the same way, using the same commands.

The GTT50A and GTT70A even have the same pixel count, 800x480, so code and images are easily interchangeable. However, please note that other sizes will have different resolutions, the GTT35A contains 320x240 pixels.

We have discussed a 10" model, but the next release will actually be the 1U-sized GTT38A. If you have a specific application for a 10" GTT, please feel free to contact sales@matrixorbital.ca to discuss such a unit in greater detail.

Cheers,
Troy