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Temperature Rating

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  • Temperature Rating

    We have a VISI program running on a GEN4-ULCD-28D display module and have seen some strange behaviour during a burn in for some devices

    Our software periodically requests data from another CPU via SPI to update the display, after 23 hours of running the device failed to request data and was reset by the slave CPU. The display module recovered then immediately failed in the same way. This did not happen with any of the other devices under test, and upon inspection, that particular device was slow to update the LCD when scrolling through screens and generally not performing well. The software has been well verified and we don't think it's the issue. Our device runs quite hot (but should be within the recommended operational temperature specification), so one theory is that the LCD can't handle the heat once placed in the enclosure.

    To investigate, we put a GEN4-ULCD-28D by itself in an oven at 60°C (below the absolute maximum temperature rating of 70°C). After some time in the oven, the LCD began exhibiting strange behaviour. When scrolling between screens the images and overlays appeared to be jumbled, as if indexes of the images 4DVISI file were incorrectly mapped. Upon reflashing the LCD and formatting and flashing the SD card, the issue was resolved. It looks at this stage like the high temperatures corrupted either the SD card or the actual graphics processor, we need to do further testing to determine the source of the problem.

    Have you seen issues with these devices - and in particular with VISI programs which utilise the SD card? Are there any further tests you can recommend to isolation the problem to the hardware? Obviously it's quite worrying to be discovering these issues at the manufacturing stage.


    Matthew Howard

  • #2

    How long have you been using the display? It may be stress due to its exposure to high temperatures over a long time and can affect the device's reliability. Can you send a video showing the issue?

    Best Regards