IsoCore: A personal, custom STM32F405 derivative of the pyboard

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akronmacon
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IsoCore: A personal, custom STM32F405 derivative of the pyboard

Post by akronmacon » Sun Oct 28, 2018 10:33 pm

I'm sharing my own personal derivative of the pyboard, the IsoCore. I designed it primarily for my own personal ecosystem and learning/experimentation.

Image

It drops the accelerometer, but adds a card-edge PCIeX1 connector. I chose - and abused - the PCIeX1 as I believe it's likely going to be available for a long while relative to the scale of a home-lab ecosystem.

It runs the stock 1.9.4 pyboard image provided you bridge PA9 to VUSB with a 560R for USB use. (This could also be done off-board).

I developed it using CircuitStudio [Altium's lighter offering].

Everything is available on BitBucket.

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WhiteHare
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Re: IsoCore: A personal, custom STM32F405 derivative of the pyboard

Post by WhiteHare » Mon Oct 29, 2018 1:20 am

How much to get one made at MacroFab?

akronmacon
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Re: IsoCore: A personal, custom STM32F405 derivative of the pyboard

Post by akronmacon » Mon Oct 29, 2018 4:27 am

From MacroFab it looks like about $72/board turnkey - they do the PCBs and bring in the components.

It drops off quickly if you order a few - I did QTY 4.

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devnull
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Re: IsoCore: A personal, custom STM32F405 derivative of the pyboard

Post by devnull » Mon Oct 29, 2018 6:30 am

would be interested to know what it worked out to per board for the 4 that you had made ?

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pythoncoder
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Re: IsoCore: A personal, custom STM32F405 derivative of the pyboard

Post by pythoncoder » Mon Oct 29, 2018 7:20 am

Nice board :D

How do you access the PCIeX1 interface from Python?
Peter Hinch

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devnull
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Re: IsoCore: A personal, custom STM32F405 derivative of the pyboard

Post by devnull » Mon Oct 29, 2018 8:36 am

I don't think it is actually PCIex compatible, I think he is just using the connector format for expansion ?!

akronmacon
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Re: IsoCore: A personal, custom STM32F405 derivative of the pyboard

Post by akronmacon » Tue Oct 30, 2018 1:04 am

@devnull is correct - I'm just using the connector for my own expansion not in a compliant form. This is not a decision I would make on a board I intended for widespread use outside my home lab. I like the supply chain prospects of the connector in the long term - hence standardizing on it for myself. I can get straight, right angle, I can expand it if I need more I/O later and stay with in the PCIeXx family, I can take a desoldering iron to any pile of surplus computer guts if I got really desperate, or I suppose, even cut and jump a motherboard if I really just wanted Hack-a-day credit.

One thing I'm playing with is figuring out what I want on an interface. I can emulate others I've seen, but through experience at home I'll get a better feel for what really is useful, what limitations (current draws, pinouts, interference/emc...) I'll run into, and what are the real limits of the different protocols and signals as I abuse them over ribbon cable/jumpers/or the like.

I've generally found that while I often am tempted to read and plan things to death, experimentation is often the best teacher - especially when the stakes are low.

@WhiteHare / devnull: To clarify on the price, $72 ea is at Qty 4; in single quantity I think it was closer to $100. For most builds I generally want at least 3 on my first order.

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