STM32F411CEU6-based pyboard-lite?

[guanabana]

Hi everyone I am kicking around the idea of making a marginally smaller and cheaper pyboard based on the STM32F411CEU6 which is the same uC as the one in the pyboard-lite except in a smaller package with less pins.

This would get rid of the SD card and accelerometer and probably VBAT pin, but keep the four LEDs and two buttons, and hopefully add a couple mosfets to switch higher currents and potentially also a LiPo charger.

This way I should be able to program the uC with the exact same firmware load as the pyboard lite (as I am not too confident in my ability to recompile micro python) and should also be more embeddable (and hopefully a bit cheaper) than the existing board.

Any thoughts or feedback or is anyone aware if someone has already done this before I charge ahead?

Thanks,
Steve

[jgriessen]

I'm starting on a similar design today with the STM32F401CBU6 in a QFN 48 package with 64k RAM, 128k flash.
It will leave off the SD card. Interested in collaborating to check details? Using open tools like KiCAD or gEDA
to create schematic and BOM? I'm going to try out the STM32F030 with 32k RAM, 256k flash, lower clock, 48 LQFP package also.

[roland_vs]

Dear all,

Wouldn't it be great not to use all the different STM versions but create a real MONSTER board running python BARE METAL on say a ZYNC chip (giving you a lot of programmable gates (some VHDL required) and two ARM cores)?

A typical MONSTER board that would do wonders: https://www.crowdsupply.com/krtkl/snickerdoodle.

Another one would be a full fledged micropy board with charger, battery, BLE, etc ready to take on some ultra low power tasks? THis might be just the one I would do in the next month or so...

Regards,

Roland

[guanabana]

Hi Roland the Snickerdoodle FPGA board is definitely cool but probably targets more high end/ complex/ cost-insensitive applications than what I am thinking about, plus I don't think it is even available for purchase yet nor could the Zynq possibly achieve the low power of the ST on the pyboard.

Anyway here is a link to my F411 board on Upverter since this thing isn't letting me upload PDFs or screenshots. Feel free to use or fork or whatever. I've still got some tweaking to do and placeholder component values for now but so far it is 1.2 x 0.7", 2 layers, and OSHpark-able. I'm hoping to get it out for fab soon so I can test out and build into some other projects I am working on.

https://upverter.com/numberone2/bae2706 ... mini-pybl/

-- Steve

[QuaakHaak]

Hi Steve,

How is your project coming along? I went and looked at your Upverter page, very interesting. Do you have a schedule for submission to a FabHab? Any idea of the initial run scale/costs etc?

Good job, Quaak.

[Turbinenreiter]

I started working on a board, too.
Man that was a bad idea.

I really like the Adafruit Feather form factor, so I pulled the design files for one of those and replaced the microcontroller with a STM32F11CEU6.



The SD card is on the bottom. Half of the pins isn't wired yet and I'm already out of space.