Teensy 3.6 with ssd1963 TFT and touch

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TrevorH

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I have been working on getting a 16bit tft working with a Teensy 3.6. With a large amount of help from Dawnmist's postings I have the tft running the
graphics demos from the UTFT libs. Has anyone succeeded in getting the touchscreen working with the UTFT_Touch libs? I am unsure which pins would
best to use for the touch. Any help would be much appreciated.

Trevor H.
 
What kind of touchscreen? Resistive? Capacitive? Is the TFT LCD a module or just a bare screen? Before anyone can help, they need to know what they're helping with. Do you have a link to the screen you have?
 
Hi, thanks for your reply, the TFTs I am using are both SSD1963 resistive 800x480 with XPT2046 touch controllers. Both these work fine with Mega and Due boards using UTFT libraries. As far as UTFT and the graphics side of things they even work fine with a Teensy 3.2 and Teensy 3.6, but the Touchscreen behaves very strangely with the Teensy boards. I can get the UTFT calibration sketch to run OK and the touch seems to work, but the results are way out of range and completely different to the calibration for the Mega or Due. The screens I have had for quite a while so no links available.

Trevor.
 
Hi, thanks for your reply, the TFTs I am using are both SSD1963 resistive 800x480 with XPT2046 touch controllers.

While I can't offer any help with the touch controller, I'm wondering if you can share what you did to get the ssd1963 based TFT working on teensy and how the performance from the teensy compares with the performance from the due.

Thank you
Gary
 
Hi Gary, You need to search out Dawnmist's postings on 16 and 8bit working with a Teensy, It is Most helpful!!

Trevor
 
Hi Gary, You need to search out Dawnmist's postings on 16 and 8bit working with a Teensy, It is Most helpful!!


I think so, too. Odd thing about the search function on this forum: If you go into advanced search and search for a username (in the author field), it ONLY shows threads that the person STARTED. (Which was why I posted the question here before finding the referenced posts.)

I'm still curious about the performance difference between using a SSD1963 TFT with a Due vs a Teensy 3.6 On the Due, it was too slow for me to use for what I wanted, so I boxed it up and stuck it on a shelf. It might be time to find that box and pull it back out. :)

Thanks
Gary
 
Clicking a user name in a post gives : 'View Forum Posts' - for Dawnmist's that should get you all - as it only goes back a limited few dozen

External search engines - Bing or other - can do a good job with the right meta words
 
Has anyone succeeded in getting the touchscreen working with the UTFT_Touch libs? I am unsure which pins would best to use for the touch.

What I'm unsure of is why you'd want to abuse yourself trying to make that library function...

Paul's XPT2046 library is a model of simplicity. Just two files with six kilobytes of SPI hardware clarity.

https://github.com/PaulStoffregen/XPT2046_Touchscreen

If you have any problems, please post a decent picture of the component side of your TFT LCD. Hopefully it's one of the usual Chinese 5.0 or 7.0 inch LCD's . Once the device has been identified, it is much easier to talk pins and signals.
 
I've been looking for a Teensy 3.5 (or 3.6) library for a 3.5" 480x320 display or the 5" 800x420 display from BuyDisplay.com. I do have Paul's display and library, but I want to use a touch screen with it. I have resistive displays in both sizes, but have not found a library for them. I'd be happy to switch to capacitive touch if I can find a library that works. I realize the last post here was about five months ago, but am wondering if everyone gave up or has someone found a solution to the touch screen/larger display problem.
 
I've been looking for a Teensy 3.5 (or 3.6) library for a 3.5" 480x320 display or the 5" 800x420 display from BuyDisplay.com. I do have Paul's display and library, but I want to use a touch screen with it. I have resistive displays in both sizes, but have not found a library for them. I'd be happy to switch to capacitive touch if I can find a library that works. I realize the last post here was about five months ago, but am wondering if everyone gave up or has someone found a solution to the touch screen/larger display problem.

You might want to look at gamedunio3 that just exited the kickstarter delivery stage, and now is shipping:

According to the above link, the specs are:
  • 4.3" display using the FT810 GPU for display, touchscreen, etc.
  • video output is 480x272 pixels in 24-bit color
  • OpenGL-style command set
  • Up to 2000 sprites, any size
  • 256 Kbytes of video RAM
  • smooth sprite rotate and zoom with bilinear filtering
  • smooth circle and line drawing in hardware - 16x antialiased
  • JPEG loading in hardware
  • built-in rendering of gradients, text, dials and buttons
  • sound output is via an amplified headphone jack
  • resistive touch screen

Gamedunio3 has support for Teensy 3.2, Arduino Uno, and Wemos D1 R1 (ESP8266). Note, I have the Gamedunio3, but I haven't done much other that run a few examples. I know the retail sales is operating because the GD3 I bought during the kickstarter stage got knocked to floor by my cats and the screen was shattered, so I bought another one.

Yeah, it would be nice to get the buydisplay.com displays working, but the GD3 might be useful.
 
Michael: I replied once and thanked you then, but I don't see it here. Anyway, I have since ordered one and we'll see how it works out. Thanks again!
 
I find this puzzling. As popular as the Teensy 3.5/6 are, other than Paul's display (which I have), I cannot get any vendor to say they have a graphics library that works with their display. First, I confess I am not a hardware guy, but am pretty good on the software end. Because of no EE knowledge, this may be a dumb question, but is there something about the Teensy hardware that makes it difficult to interface with a touch screen display? Paul is blessed with both hardware and software skills, which I am not. Nor do I feel I could invest the time to write the library interface to a specific display. I'm trying to tie the display to some amateur radio equipment and I would like it to work with the Teensy rather than an Arduino, mainly because of the speed and resource pool the Teensy brings to the party. Anyway, if anyone else has an ideas, I'd love to hear them.
 
There is a sweet spot on the ILI9341 with 320x240 resolution on SPI - and cost. And it had an SPI controller that was fast and good to work with. The original small screen was interfaced and optimized from AdaFruit library to be VERY fast by Paul and worked really well on the T_3.2 - then one day the TOUCH version was supported on the larger 2.8" and it worked well with the controller that comes with - it got interrupt handling support for touch to minimize detection polling and then DMA support to allow continuous updates on the larger RAM of the T_3.6 that leaves some working room even with a full 150KB in memory copy of the screen with 16 bit color.

So far nothing else bigger/better has come along that had a similar sweet spot it seems - though VGA works pretty well - though that isn't touch aware.
 
Thanks, Defragster. We are still experimenting with the 2.8" but it's a little "dense" for all the stuff we're sticking on the display. We're also testing the idea of paging in a second page for lesser-used features. Ideally, we'd have a 3.5" or 5" display, but I just can't seem to find one.
 
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