Fat Cache Error! (and blue screen) video streaming using TWFILE

Software Development
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I’m developing video streaming on 4.3 Intelligent display using TWFILE and 4096 byte packet “subcontracting” in transparent transmission mode…

I’m attempting to manage the buffer tightly on the MCU and deal with the handshake 05 etc…

I keep getting a blue screen of death on the device and same happens on simulator

Does anyone know what condition triggers this state? it might help me debug my code if I knew what the Nextion thinks is wrong… Thanks :slight_smile:

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Hey! This is the most creative thing I have seen to be done on Nextion, and actually thought about doing something like this a while back. While I can’t be sure, FatCache Error means that there is a buffer overload going on, and the system is unable to keep up. My guess is you have an image file set in the editor as the image source, and you update the file by stream, so you have to cut down on how much you update the file per period.

UPDATE
Yes! That’s buffer overflow, look carefully in the serial output “24 FF FF FF”

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Another note, make sure that bkcmd is set to 0 while you do an active transmission.

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Hi Xwintk - Thanks :slight_smile: - I’m working to tigten up the serial writes to avoid overrun… that’s helpful because of course I had bkcmd=3 for general debugging purposes. And yes when I defined the exp0 control I set path in editor to non-existent “ram/0.jpg” which causes 0x06 invalid file operation once when nextion starts up. I’ll post the app when I get it working (as of now i have the ESP in the middle like traffic cop grabbing a frame from the OpenMV cam via socket and serial.writing to the Nextion). Cheers

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Great! Waiting for updates.