Uzebox with TFT Display

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Drean
 
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Uzebox with TFT Display

Post by Drean »

I would like to connect an Uzebox with a NTSC/PAL TFT Display- 3.5".

https://www.adafruit.com/products/1291
https://www.adafruit.com/products/913

But when I connect the video cable, it seems to have a timing issue, the image scrolls up continuously. The Uzebox work perfectly with a TV.

How can I fixed this problem?

thank you

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adafruit_support_rick
 
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Re: Uzebox with TFT Display

Post by adafruit_support_rick »

Your vertical sync signal seems to be missing. Please post clear, detailed pictures of both sides of your UzeBox board, so we can check the assembly and soldering.

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Drean
 
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Re: Uzebox with TFT Display

Post by Drean »

Thank you for your answer, here are the pictures requested. For information, I tried the screen on a wii console and everything worked fine. I also tried the Uzebox on 2 differents televisions and it worked well.

On the picture, you will perceive that the resistors R5, R9 and R17 are 1.6 K instead of 1.58K (on the schematic). The 1.58K resistors were not in the kit I received, therefore I replaced them by a similar value that I had on hand.

Thank you in advance for your help.
front side
front side
IMG_0002.JPG (214.09 KiB) Viewed 281 times
back side
back side
IMG_0004.JPG (205.38 KiB) Viewed 281 times
Screen
Screen
IMG_0007.JPG (204.18 KiB) Viewed 281 times

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adafruit_support_rick
 
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Re: Uzebox with TFT Display

Post by adafruit_support_rick »

Nice build :)

The fact that the screen works with other sources, and the uzebox works with other displays makes this difficult. I'm going to ask around to see if anybody has any ideas.
Meanwhile, have you tried the uzebox with both video inputs on the screen?

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Drean
 
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Re: Uzebox with TFT Display

Post by Drean »

Hi,
I tried both video inputs and it does not work.

I do not have much knowledge of video signal, however I did some tests with an oscilloscope and it seems that there are small differences between the levels of tension between uzebox and a camero video.

The sync pulse from camera is -400mV. And the sync pulse from Uzebox is -200 mV. According to the website of the national instrument the sync pulse of NTSC signal should be around -300 mV. Do you think this might explain my problem? (http://www.ni.com/white-paper/4750/en/)

Here are the screenshots I took.
Signal from sony camera to TFT screen
Signal from sony camera to TFT screen
camera.JPG (147.48 KiB) Viewed 267 times
Signal from Uzebox to TFT screen
Signal from Uzebox to TFT screen
uzebox.JPG (142.19 KiB) Viewed 267 times
I'll put zoomed images in the next post.
Thanks.

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Drean
 
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Re: Uzebox with TFT Display

Post by Drean »

Here is the zoomed picture. You can easily see the difference between the voltage levels.
Signal from Uzebox
Signal from Uzebox
uzebox 2.JPG (139.74 KiB) Viewed 267 times
Singal from Camera
Singal from Camera
camera 2.JPG (135.1 KiB) Viewed 267 times
Thanks

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adafruit_support_rick
 
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Re: Uzebox with TFT Display

Post by adafruit_support_rick »

Looks like a smoking gun to me. I can try replacing the uzeBox.
Please email [email protected] with a link to this thread for a replacement uzeBox.

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