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3.5" TFT 320x480 goes blank after a few hours
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3.5" TFT 320x480 goes blank after a few hours

by femur on Sun Feb 17, 2019 5:23 pm

Hello,

I've been working with the 3.5" TFT 320x480 TFTLCD screen for a few years now and I've consistently run into a problem that I can't seem to solve. After many, or sometimes just a few hours of running a project, the screen will turn gray and no text will show. I've been printing simple text from a photon microcontroller and I've tried replacing everything in the system but I still get the gray screen within 24 hours of running the project. If I restart everything, it will work again but after a period of time, I'm back to the gray screen.

I'm using the SPI hookup, as shown here: https://learn.adafruit.com/adafruit-3-5 ... g-and-test
though I am using 3.3v from a photon.

I am providing more than 1.5 amps from the power supply so I don't think that's an issue. However, I do suspect a power issue. Maybe the vreg on the photon? Ideally, I'd like to run the screen 24/7. This "gray screen" happens even with the "deadbeef" example code.

Any ideas? Thank you!

femur
 
Posts: 13
Joined: Sun Jan 22, 2012 9:53 pm

Re: 3.5" TFT 320x480 goes blank after a few hours

by MRUK on Sat May 11, 2019 4:39 am

I've just spent several hours tracking down a similar problem. In my case it was caused by the APX803 voltage monitor, IC4 randomly resetting the display due to noise spikes on the 3.3V supply.

I soldered a 100nF capacitor across the Vcc and GND pins of IC4 and it cured the problem completely.

MRUK
 
Posts: 1
Joined: Sat May 11, 2019 4:20 am

Re: 3.5" TFT 320x480 goes blank after a few hours

by femur on Sat May 11, 2019 10:55 am

Wow! Thank you MRUK! I'm excited to try this. I've been struggling with this problem for months. I'll let you know my results.

femur
 
Posts: 13
Joined: Sun Jan 22, 2012 9:53 pm

Please be positive and constructive with your questions and comments.