Strange problem - guru meditation :)

I have a strange problem here - maybe somebody has experience in this area and might think of a solution.

We have build a straightforward GUI. It consists of several screens, which can be swiped (gestures on a touchpanel) left and right. On some screens we use dialogs, which pop up to ask for some input.

For documentation purposes we have also programmed some screenshot functionality, so: if somebody gives the commadn !screenshot over the usb-serial, a handler will fetch the pixel-data and send it over the serial line where the receiver saves it as bitmap to disk.

What we see here is, that for every screen this code works perfect. But if we show dialogs, the code crashes immediately.

Does anybody know, what might go wrong here?

TIA
Marc

Hello Marc,

Perhaps you are running out of memory…

How do you take these screenshots, I suppose it just copies the (internal) framebuffer to some serial data? This way it would not have anything to do with LVGL directly.

Kind regards

Thanks, I will check that (again)
But I already thought of RAM problems while designing and as the transport channel is soo slow, I use code which fetches pixel by pixel and transfers it, so no big buffers (I think it is sized 16bytes big).

A buffer of 16 bytes, that could hardly be the problem then! I’m puzzled.

Are these dialogs just LVGL objects overlayed on top of your regular screen or something?