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USBizi On newer, larger, faster chips?


#1

Any chance you will soon offer USBizi on newer ARM single-chip microcontrollers with more memory and faster clocks? I am slavering over the STM32F405RGT6 for example, 1MB ROM, 196KB RAM, 168MHz clock. Since all the extra memory would be available for user programs, this would make an enormous difference to the types of project that could be tackled.

As memory sizes slowly creep up, I am convinced that single-chip is the way to go rather than the Spider/Hydra approach as this keeps the cost down to Arduino levels and also increases the IO counts since pins are not taken by external memory busses.

Maybe even a single-chip Gadgeteer would be feasible?


#2

I wouldn’t be surprised if the new Gadgeteer (after the Hydra) that Gus has under wraps isn’t something like this. Some people have already implied it would be a smaller form factor.

-Eric


#3

The newer micros do indeed have more RAM and flash, but they’re nowhere near the levels that multi-chip solutions provide:

Hydra: 16MB RAM, 4MB flash
EMX: 16MB RAM, 4.5MB flash
ChipworkX: 64MB RAM, 8MB flash (+256MB flash)

I don’t know what kind of flash the Gadgeteer libraries require, but I wouldn’t be completely shocked if it could fit in 1MB of flash. I don’t know how much room you’d have left over. Furthermore, you wouldn’t be able to do a lot of the things that most would expect to be able to do, given the current crop of Gadgeteer hardware, such as large full-color graphical displays and cameras.

I think that a small-scale Gadgeteer hardware option is a fine idea, but you’d need to be very clear on the capabilities you’d be sacrificing in the name of size and cost.


#4

Yes, but:

USBizi (incl Panda, Domino): 96KB RAM, 512KB flash.

It does pretty much everything gadgeteer does with the possible exception of cameras (there is a color display panel for the Panda II). I’ve always been really puzzled by the huge difference in memory between the chip and module products and kind of assumed that the modules had that much because they could rather than because they needed that much. I just bought a micro SD card for my Panda and could not find one less that 2GB - MASSIVE overkill for what I’m doing!

True the latest chips are only about double the RAM and Flash of the current USBizi chips, but that would mean about 700KB flash free for the application as opposed to under 200KB at present.


#5

Flash is pretty much never the limiting factor, it’s RAM. Gus is convinced (and I’m guessing he’s right) that noone has ever run out of flash on USBizi without running out of something else first.

Specifically for graphical applications, you need large memory buffers to construct and manipulate bitmaps that can be sent to the screen. Otherwise, you’re stuck doing what the FEZ Touch does: sending one pixel at a time. While this is quite workable (especially for simple user interfaces), it makes it very difficult to do more advanced things (like double buffering for greater speed).


#6

@ godefroi
Did you see my post in my porting thread about a new Freescale Cortex-M3? Upto 4MB flash and 512KB ram, at 200MHz. All in a single chip… ;D


#7

My application is currently reporting Total: (15792 RAM - 143940 ROM - 69639 METADATA) which (according to information from Gus) means I have only about 37KB left. The GC report is: GC: 2msec 33396 bytes used, 30984 bytes available. I’d like to add SystemUpdate, but from the documentation that would take 48KB ROM.


#8

@ Errol: do you have a reference on that chip? I cannot find anything more than 512KB/128KB on Freescale’s parametric search: http://www.freescale.com/webapp/search/MainSERP.jsp?SelectedAsset=Product%20Pages#breadcrumb_anchor and that is Cortex-M4.


#9

http://www.freescale.com/webapp/sps/site/overview.jsp?code=KINETIS_X_SERIES&tid=mKHp


#10

wonder when they’ll be orderable. K70 looks not to bad except for some weird BGA footprint and 256 pins :slight_smile:


#11

Don’t know when. I have been waiting, what?, 12 months, maybe?, for their software define radio cpu chippie thingy…


#12

At 512K RAM, you’re into the realm of feasibility, but you wouldn’t have much RAM left over after your frame buffer consumes most of it. Cameras are still out, except for very low resolution shots.

BGA form factor makes it extremely hobbyist-unfriendly (Gus hasn’t yet produced a 4-part series on hand-soldering BGAs. Get to it, Gus! :wink: )

If you’re looking for high-end modules, then EMX/ChipworkX are what you want, or Spider/Hydra in the Gadgeteer line.