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Can't get 3.5" PiTFT to work - white screen
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Can't get 3.5" PiTFT to work - white screen

by vladiks on Thu Oct 12, 2017 7:59 am

Hello,

I am unable to get my 3.5" PiTFT touchscreen to work. At first I tried to make it work on custom PCB made for Pi compute board. After some time, I wanted to exclude option, that our PCB, or combination TFT with compute module, is wrong. So now I connected PiTFT to Raspberry 2 model B and the result is still the same - the screen is still all white. I can only change the backlit using GPIO pwm. I am using "Jessie Lite-based PiTFT 3.5" Resistive Image for Pi 1, Pi 2 and Pi 3 (Sept 23, 2016 image, made Nov 10)".

I attached dmesg output. I guess there is some problem in spi communication:
Code: Select all | TOGGLE FULL SIZE
[    6.710558] stmpe-spi spi0.1: unknown chip id: 0x0
[    6.710623] stmpe-spi: probe of spi0.1 failed with error -22

In the meantime, I am waiting for other display to exclude hw error...
Please advise
Attachments
dmesg.txt
(21.48 KiB) Downloaded 2 times

vladiks
 
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Joined: Wed Oct 11, 2017 7:55 am

Re: Can't get 3.5" PiTFT to work - white screen

by adafruit_support_rick on Thu Oct 12, 2017 12:06 pm

stmpe-spi is the touch controller chip. So it's not finding that. But it is finding fb_hx8357d, which is the display controller chip.

I wonder if your ribbon cable is loose or not seated properly. See this picture:
https://learn.adafruit.com/adafruit-pit ... faq#faq-15

If you still have problems, please post a picture of the bottom of the PiTFT.

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Re: Can't get 3.5" PiTFT to work - white screen

by vladiks on Fri Oct 20, 2017 4:50 am

Sorry it took me so much time. Finally the other display arrived and worked out of the box. I guess it could be wrong ribbon placement, but I am not able tu push it further in the socket, because it is too short... see images attached. The ribbon on the other display looks almost the same and it works.

The other thing is, I was not able to apply calibration for the desired display rotation. Nothing from this page https://learn.adafruit.com/adafruit-pit ... -calibrate worked until I used advice from this answer https://www.raspberrypi.org/forums/view ... 8&t=179477. Now the automagic calibration works like a charm and the cursor moves precisely with my touch.
Attachments
IMG_20171020_092747.jpg
ribbon_2
IMG_20171020_092747.jpg (193.99 KiB) Viewed 30 times
IMG_20171020_092729.jpg
ribbon_1
IMG_20171020_092729.jpg (219.67 KiB) Viewed 30 times

vladiks
 
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Re: Can't get 3.5" PiTFT to work - white screen

by adafruit_support_rick on Fri Oct 20, 2017 9:38 am

Glad the second display works for you.
Please email support@adafruit.com with a link to this post for a refund on the defective display

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