SD card capabilities

Hi Jonne,

The ideas are looking better and better. The latest design only puts three items on the screen at a time. Maybe you could keep the earlier design as well and have these be two modes? I can imagine having all manner of programs and experiments in the file system, so being able to see more at once could be helpful.

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Having multiple modes is not nice, because it all used up your valuable coding space. Each mode takes up a few kB’s of memory

That’s one of the reasons I haven’t run it yet. I know what you are doing in code (its similar to the plasma demo you did earlier), and I’m sure it needs optimization in hardware.

How about like this?

I kind of :heart:the “VHS-tape” proportions of the info box on the right side, and I am ready to go with this plan.

This means 32x32 pixel icon at 16 freely selectable colors + 6 lines of text @ 9 characters per line, and freely selectable color for each line of text. Then you can make it as fancy as you like.


This is looking pretty good! What about having the icon above the text though? I guess either way it looks good.

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I’ll try it now…

Yep. Much better.

I don’t dwell on these things. Unless someone really has a different super-duper idea, this is the format that the loader will use. Now back to coding.

Edit: if the author does not provide icon, we will use @VonBednar 's standard SD card icons


That is the best version yet :slight_smile: When there is no custom icon I would like to see some useful (or funny!) info on the right view, not just the zoomed default icon: the MCU temperature, the Pokitto uptime in microseconds, the battery state, the total files count, the recent files list, a random quote of the day? :stuck_out_tongue_winking_eye: etc.
Maybe also the clock could be moved there, as you do not need to check it all the time. You also get more items to the program list if the title “All games” is moved a bit up.

I got past the ‘fast forward’ issue by adding a manual delay. It runs ok in the simulator at least.

The loader is mere 2-3 hours away from ready. Its already updating the system. I am just brushing up the interface, the core code is working like clockwork.

:sweat_smile: feeling relieved

edit: ready means its functional and can swap programs. Naturally the UI still needs finetuning and testing

edit: probably need to add some sort of CRC checks also to verify code is properly loaded before the loader quits

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Going to try the loader with a real game now.

Super excited :laughing:

Hmm… what game will have the honor of being the first ever loaded from SD card…

I have decided @catsfolly and @Aphrodite will get the honours.

Squiddy it will be.

Video coming if it works



Dangers of removing USB devices unsafely demonstrated right here today, courtesy of yours truly.

So test.bins are written to flash properly, but squiddy.bin only produces zeroes.

And I am stepping through the code, watching memory space in raw hex etc.


a terrible thought

“maybe the squiddy.bin file is not OK?”

I open it and its full of zeroes.

I had pulled the SD card from the PC too soon.

Now we try again, after a wasted hour.


On this day, at 5 pm Finland time, Squiddy by @Aphrodite and @catsfolly became the first program ever to be loaded from the SD card.

We have gaming on the go: you can load programs from SD card while travelling.

I always knew I would make it work but now we have it, just in time before shipping.

Video proof coming later today, but now I need to rest my head for a while.


Excellent news :slight_smile: !


Nicely done! Congratulations! I was surprised to see the load take more time than a blink of an eye. Is that because of Flash programming?

Thanks! There were several “blind spots” i.e. mysterious hangs at difficult to debug spots. Most of them were about initialization of the MCU and init of the C runtime. Every time you hit one of those snags the first thought is “oh my god, how many days of debugging will this take again”. That is why I was slightly worried about my promise that the SD loader will work. But now were on the home stretch, its just routine cleanup from here.

Actually optimization is completely off in that code. I need to turn it back on.

But yeah, even with a hw debugger writing the flash is not very fast - on all mcus. Its got something to do with the architecture of the memory.

I must say it feels great to see squiddy running on a pokitto from an sd card, thanks a lot! @jonne


Awesome !!! :ok_hand:

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