5 ms·

I haven't yet worked on automotive stuff but I work in the embedded space. We're using small MCU (not CPU) to drive 480x272 or 800x600 screen. 240Mhz, 8MB of R

by gjadi 3y ago

I haven't yet worked on automotive stuff but I work in the embedded space. We're using small MCU (not CPU) to drive 480x272 or 800x600 screen. 240Mhz, 8MB of RAM. For example on ESP32-S2 or ESP32-S3. If you had GPS, bluetooth, wifi, etc. to the mix, yeah that's a challenge and you need to make your UI pretty simple.

londons_explore 3y ago
Nearly everything automotive now has a GPU. When you have a GPU, even a very low power one, graphics get far easier. simple operations like "fade from this screen into that screen at 60 fps" become easy. They would be impossible with CPU graphics, simply because a slow CPU can't update every pixel on the screen at 60 fps anyway. Despite that, automotive graphics ramain laggy because they normally build something barely gpu accelerated using java or QT or something else laggy by nature...
- gjadi 3y ago
  Yeah a GPU makes things easier. Note that you can do it with Java, we do it at $work. Anyway, when you're designing your UI, you've to take into account the computation power available and design around that, otherwise you're doomed.
- jlokier 3y ago
  At the highest resolution of the GP comment, 800×600, and a 240MHz CPU/MCU and 8MB RAM, 60fps smooth updates for things like scrolling, scaling, and drawing new buttons and icons should normally be possible with the CPU alone. Fading and blending large areas of the screen won't be, but small areas will be fine. Basically anything that involves copying pixels or solid fills without per-pixel calculations. 60fps at 800x600 is 28.8Mpixel/s. Copying and filling at that rate should be achievable by a 240MHz CPU with some tight coding. The rest is 2d geometry, mostly axis-aligned, with relatively few edges. That's not demanding at all. (I used to write 2d and 3d rendering engines for slower CPUs than that.) A GPU is necessary for fancier effects like fades and shading, but the basics can be smooth on a CPU and the fancy stuff too if confined to smaller areas. Also, for the car, people would be happy enough if it could do a consistent 30fps I think. Those annoyingly slow GUI updates you tend to see on TV set top boxes are not slow because of the hardware... it's usually the software not being written with sleedy rendering in mind. All that said, you're right that if there's a GPU or even just a Blitter, it should be used and then the CPU speed almost doesn't matter as the geometry calculations are so simple.
antisthenes 3y ago
Automotive is different. They're selling a $30,000 car attached to every CPU, there's no reason to have to penny-pinch on the hardware, when an additional $50 would quadruple the specs.

by gjadi 3y ago

londons_explore 3y ago

Nearly everything automotive now has a GPU. When you have a GPU, even a very low power one, graphics get far easier. simple operations like "fade from this screen into that screen at 60 fps" become easy. They would be impossible with CPU graphics, simply because a slow CPU can't update every pixel on the screen at 60 fps anyway. Despite that, automotive graphics ramain laggy because they normally build something barely gpu accelerated using java or QT or something else laggy by nature...

gjadi 3y ago
Yeah a GPU makes things easier. Note that you can do it with Java, we do it at $work. Anyway, when you're designing your UI, you've to take into account the computation power available and design around that, otherwise you're doomed.
jlokier 3y ago
At the highest resolution of the GP comment, 800×600, and a 240MHz CPU/MCU and 8MB RAM, 60fps smooth updates for things like scrolling, scaling, and drawing new buttons and icons should normally be possible with the CPU alone. Fading and blending large areas of the screen won't be, but small areas will be fine. Basically anything that involves copying pixels or solid fills without per-pixel calculations. 60fps at 800x600 is 28.8Mpixel/s. Copying and filling at that rate should be achievable by a 240MHz CPU with some tight coding. The rest is 2d geometry, mostly axis-aligned, with relatively few edges. That's not demanding at all. (I used to write 2d and 3d rendering engines for slower CPUs than that.) A GPU is necessary for fancier effects like fades and shading, but the basics can be smooth on a CPU and the fancy stuff too if confined to smaller areas. Also, for the car, people would be happy enough if it could do a consistent 30fps I think. Those annoyingly slow GUI updates you tend to see on TV set top boxes are not slow because of the hardware... it's usually the software not being written with sleedy rendering in mind. All that said, you're right that if there's a GPU or even just a Blitter, it should be used and then the CPU speed almost doesn't matter as the geometry calculations are so simple.

antisthenes 3y ago

Automotive is different. They're selling a $30,000 car attached to every CPU, there's no reason to have to penny-pinch on the hardware, when an additional $50 would quadruple the specs.