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Glitchy display (video) PiTFT Plus 320x240 2.8" TFT + Capaci
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Glitchy display (video) PiTFT Plus 320x240 2.8" TFT + Capaci

by felleg on Sun Jun 11, 2017 12:47 pm

I bought a 2.8" Capacitive PiTFT Plus on April 26 and everything had been great so far up to this point, but about a week ago a problem started happening with my PiTFT that made it sadly unusable. I use my PiTFTpiTFT (2.8", capacitive) to play games on it via RetroPie (I currently use the latest version of 4.2, I update my raspberry pi about every 2 weeks). I set it up using this tutorial from Adafruit itself: https://learn.adafruit.com/adafruit-pit ... sy-install. It has been working great for about a month, and only recently started dropping frames and glitching out in messy colors. Sometimes it also becomes completely white in the middle of gameplay and does not recover without a complete Raspberry Pi reboot. Here is a video that illustrates this: https://www.youtube.com/watch?v=aUQUyf0G2x4


I can assure you, I have tested about 10 times that connection were aligned and tight over the I/O pins (over which the piTFT connects). I am not an engineer, so I don't really know how to test the voltage on the pins and I don't even have the proper equipment to do so. All I can say is that neither my raspberry pi or the piTFT have been dropped or suffered physical damage as far as I can tell. They are usually sitting on my desk, or stored in a protective pouch inside a plastic case (see pictures attached). Here's a quick description of every picture:

Pictures 1-3: [direcly attached to this post]

Picture 4: Another angle of picture 3

Picture 5: Back side of the PiTFT, everything seems in great condition

Picture 6: Front side of the PiTFT, everything also seems in great condition

Picture 7: Shows the plastic case (Short Crust Plus) in which I house my raspberry pi and PiTFT. It offers protection.


I am to my wits' end to find what causes the issue. I don't think it's a software issue because my hdmi display suffers none of these glitches, and I don't think it's a hardware issue either since the PiTFT has been working without any flaw for about a month and has suffered no physical damage.


Should the item be replaced? Do you have suggestions on how I could fix this issue? Thanks in advance.
Attachments
picture 3.jpg
Shows I/O pins of my raspberry Pi (unconnected), the only defect I could find is rightmost pins are bent a light amount, but this should not affect performance.
picture 3.jpg (83.59 KiB) Viewed 224 times
picture 2.jpg
Shows another angle to show I/O pins alignment is OK
picture 2.jpg (101.55 KiB) Viewed 224 times
picture 1.jpg
Shows that connections are flush, yet this is the setup that produced the linked video
picture 1.jpg (92.17 KiB) Viewed 224 times

felleg
 
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Re: Glitchy display (video) PiTFT Plus 320x240 2.8" TFT + Ca

by felleg on Tue Jun 13, 2017 7:30 pm

Bump... Please help :(

felleg
 
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Re: Glitchy display (video) PiTFT Plus 320x240 2.8" TFT + Ca

by scruss_elmwood on Fri Jun 23, 2017 5:30 pm

Hi - I work for the reseller from whom the OP bought the PiTFT Plus. We've been working with the customer to resolve the issue, but we've reached the limit of our diagnostic knowledge of this product

The customer sent us some kernel log details. These included output from the kernel module used by the display:
Code: Select all | TOGGLE FULL SIZE
[    4.510632] fbtft: module is from the staging directory, the quality is unknown, you have been warned.
[    4.522028] fb_ili9340: module is from the staging directory, the quality is unknown, you have been warned.
[    4.523784] fbtft_of_value: buswidth = 8
[    4.523810] fbtft_of_value: debug = 0
[    4.523820] fbtft_of_value: rotate = 90
[    4.523832] fbtft_of_value: fps = 60
[    4.530132] input: ft6236 as /devices/platform/soc/3f804000.i2c/i2c-1/1-0038/input/input2
 ...
[    4.706156] graphics fb1: fb_ili9340 frame buffer, 320x240, 150 KiB video memory, 4 KiB DMA buffer memory, fps=100, spi0.0 at 80 MHz

I have a couple of questions:
  • Earlier PiTFT setups seemed to use a value of fps=20, and yet the customer's machine is set (through running recent Adafruit scripts) to 60 fps. Would this be likely to be causing glitches?
  • With recent Raspberry Pi kernels, are the Adafruit custom modules and overlays still necessary? I understand that touchscreen might require its own driver.
  • Do you have all the information you need to diagnose this problem?
The customer wishes to use this screen for gaming, and while setting fps=20 seems to be stable for a short while, it apparently makes game play very rough.

Looking forward to your response!

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Re: Glitchy display (video) PiTFT Plus 320x240 2.8" TFT + Ca

by adafruit_support_rick on Sat Jun 24, 2017 9:20 am

I don't think it will actually run at 100fps. I think ~26fps is the best you can manage, since the max SPI data transfer rate the TFT will support is 48MHz. But the fps=100 setting is a 'suggestion'. It will run as fast as it can.

In one of the pictures, the black 'ears' on the ribbon cable connector may be a little loose. See if you can push them in at all.

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Re: Glitchy display (video) PiTFT Plus 320x240 2.8" TFT + Ca

by felleg on Mon Jun 26, 2017 11:17 pm

Hello Rick,
Thanks for taking the time to reply. I find it weird that the log I produced said that I had my screen set at 100 fps. The reality is that all along it was set to 60 fps: from the moment I received it, to a month later when the screen started failing, this setting never changed. After reading your post, I was tempted to change my settings to see if the screen could handle the values you mentioned. At this point, I think it would be useful for you to have a quick glance at my config.txt file to see exactly what I have set up: https://pastebin.com/CW2F36A8

The lines that I think will be of interest are the following:
# --- added by adafruit-pitft-helper Tue Jun 20 23:33:56 EDT 2017 ---
[pi1]
device_tree=bcm2708-rpi-b-plus.dtb
[pi2]
device_tree=bcm2709-rpi-2-b.dtb
[all]
dtparam=spi=on
dtparam=i2c1=on
dtparam=i2c_arm=on
dtoverlay=pitft28-capacitive,rotate=90,speed=49000000,fps=26
# --- end adafruit-pitft-helper Tue Jun 20 23:33:56 EDT 2017 ---
display_rotate=0
hdmi_cvt=320 240 60 1 0 0 0


The speed value is 49000000 (which will be rounded down to 48MHz, see this section from the Adafruit FAQ) and the fps is 26. Also, most importantly, I am using a Raspberry Pi 3B with the most up-to-date RetroPie version (4.2), and updated the raspberrypi-kernel to the most recent version (1.20161101) using this method. Even with these relatively low settings, the screen glitched out by going totally blank (I had to restart the Pi, and it blanked once more after a few minutes). I don't think the `loose` connections should be a concern. I pushed them as hard as I could before I felt I could damage the boards. Here's a picture of how the connection looks like right now: http://img.photobucket.com/albums/v707/ ... f4tqcl.jpg

The most reasonable trade-off I could find is a speed of 32000000 and fps of 30. With these values, it does not blank out. However, it would be unthinkable to play a video game with this refresh rate. Here's a sample of how Sonic the Hedgehog looks on the screen: https://www.youtube.com/watch?v=yyQNfP8bGrw

To say the least, if this looks abnormal to you, I'd love to know how to fix this issue once and for all. However, if this performance meets what you expect from capacitive Adafruit PiTFTs, I must say that I not only am disappointed, but I believe your documentation about this device is misleading. For example, this article in your how-to section clearly praises the PiTFT as a device able to display retro games "quite effectively now". Unless the games you tested are Chess and Backgammon, or something that doesn't require a high framerate, the device is clearly unsuited for gaming, as you can see from my video. I digress.

I find it highly unlikely that the performance of my PiTFT meets your expectations. Looking at this Adafruit video which helped me set up my PiTFT, you can see how fluidly DOOM runs on another PiTFT. I haven't recorded DOOM footage since I don't have it installed, but I'd expect the performance of my PiTFT to be just as bad with that game. If you look at this specific timemark, you will also see the settings used for the PiTFT in the video. They are exactly the ones I had been using in the past, and you can see on the web browser in the video that these settings were even recommended in the how-to section of the Adafruit website.

I know this post contains a lot of information, but the bottomline is: I highly doubt what I'm seeing on my end is normal. Even at `stable` and `recommended` settings, my display struggles, whereas the Adafruit video I linked clearly shows a much higher framerate than what I can achieve right now. My PiTFT used to be that good, but now it is not. Did overclocking it break it? Is there a way to find out?

Cheers,
Felix

felleg
 
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Re: Glitchy display (video) PiTFT Plus 320x240 2.8" TFT + Ca

by adafruit2 on Tue Jun 27, 2017 12:42 pm

you probably didnt break it, but it is technically overclocking it. (the screens are not spec'd for high SPI speeds). that said it could be something else. if you run the screen at 32mhz does it basically run forever?

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Re: Glitchy display (video) PiTFT Plus 320x240 2.8" TFT + Ca

by felleg on Tue Jun 27, 2017 6:25 pm

At 32MHz, it seems to be more stable, and for the most part does not blank out, but then again, just recently, it started glitching out once more even at 32MHz, 30 fps (see http://img.photobucket.com/albums/v707/ ... yiuybv.jpg). Doesn't happen every time.

With these settings, the biggest problem is that this device is absolutely unsuited for gaming. Again, if you intended this to be used as a gaming device un-overclocked, it is simply not quick or stable enough, as you saw from the video I posted. It has to be overclocked to be useful at all.

Edit: What I really want to know is: why did overclocking it only work for a single month, if it's not damaging the components?

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Re: Glitchy display (video) PiTFT Plus 320x240 2.8" TFT + Ca

by adafruit2 on Tue Jun 27, 2017 7:02 pm

well, we're not sure since you're the first person to have this specific issue...but we can try replacing it. email support@adafruit for a replacement. thanks! :)

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Re: Glitchy display (video) PiTFT Plus 320x240 2.8" TFT + Ca

by felleg on Tue Jun 27, 2017 7:10 pm

I understand, thank you so much for your comprehension. Unless you think I should do otherwise, I will use that second screen with overclocking settings (speed = 80000000, fps = 60, as the Adafruit video on YouTube suggests) and I will report back if anything similar to my current experience happens.

felleg
 
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Please be positive and constructive with your questions and comments.