Search found 7 matches

by akronmacon
Thu Mar 07, 2019 6:10 am
Forum: General Discussion and Questions
Topic: USB ID Pin function
Replies: 3
Views: 263

Re: USB ID Pin function

If I understand correctly, you're looking to take a stock image (like the pre-made pyboard image) and get it working with your board. In that case I believe you need to pull pin A9 up. If you look at the PyBoard Schematic ( http://micropython.org/resources/PYBv11-schematics.pdf ) you can see this is...
by akronmacon
Tue Oct 30, 2018 1:04 am
Forum: Hardware Projects
Topic: IsoCore: A personal, custom STM32F405 derivative of the pyboard
Replies: 6
Views: 791

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

@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 mysel...
by akronmacon
Mon Oct 29, 2018 4:27 am
Forum: Hardware Projects
Topic: IsoCore: A personal, custom STM32F405 derivative of the pyboard
Replies: 6
Views: 791

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

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.
by akronmacon
Sun Oct 28, 2018 10:33 pm
Forum: Hardware Projects
Topic: IsoCore: A personal, custom STM32F405 derivative of the pyboard
Replies: 6
Views: 791

IsoCore: A personal, custom STM32F405 derivative of the pyboard

I'm sharing my own personal derivative of the pyboard, the IsoCore. I designed it primarily for my own personal ecosystem and learning/experimentation. IsoCore Top View It drops the accelerometer, but adds a card-edge PCIeX1 connector. I chose - and abused - the PCIeX1 as I believe it's likely going...
by akronmacon
Wed Sep 12, 2018 1:44 am
Forum: MicroPython pyboard
Topic: Avoiding the Cargo Cult: R19 and VBACKUP
Replies: 5
Views: 441

Re: Avoiding the Cargo Cult: R19 and VBACKUP

Good link for the background explanation. Thank you!
by akronmacon
Sun Sep 09, 2018 9:59 pm
Forum: MicroPython pyboard
Topic: Avoiding the Cargo Cult: R19 and VBACKUP
Replies: 5
Views: 441

Avoiding the Cargo Cult: R19 and VBACKUP

I'm designing my own version of a MicroPython board based on the PYBv1.1 for my own home ecosystem of tinkering. [And it's an instructive exercise!] When walking through the PYBv1.1 I see the note: "R19 prevents a silicon failure from short circuiting the backup battery." I imagine the reasoning is:...
by akronmacon
Thu Jun 07, 2018 5:10 am
Forum: ESP8266 boards
Topic: Filesystem: Maximum number of files/directories
Replies: 3
Views: 611

Re: Filesystem: Maximum number of files/directories

This smells like a problem we run into in scientific logging equipment, specifically with FAT file systems. Often, the default formatting for a FAT file system (FAT12, FAT16) only allows for 512 root entries in the root directory. This restriction doesn't exist outside the root directory. Both direc...