EMA = Hybrid Espruino Pico + Micropython + Arduino

[bobricius]

This is idea ...
I get Espruino pico board + arduino headers and this is crazy MIX

Because exist native DFU Micropython port for Espruino PICO you can run BOTH on same board of course you can program native STM32 code... and maybe exist STM32F4 Arduino core or .NET ????

Now in credit card shape

...There is lot of space for extra buttons ... headers .... etc ... oled, rtc, cr2032 battery RGB led, encoder, rf module or just simple card ??


https://hackaday.io/project/12222-ema-h ... on-arduino

[dhylands]

You'll probably want a reset button, and maybe a USER button (used to reset the filesystem).

You may want to look at the Netduino Plus 2: http://www.netduino.com/netduinoplus2/specs.htm
It uses a 405, but you may want to try and maintain pin compatability.

For a big board like that I'd definitely want the option for a USB connector rather than the plug directly into a USB (like the Espruino).

Having an sdcard would be a big plus, even it was just a 1 line SPI based one like on the Netduino.

The button that you do have seems to be labelled with both BOOT0 and BOOT1. I'm assuming it would be BOOT0?

You might also want to put some Grove connectors since you've got space.

[bobricius]

this is very coarse layout ....
I want use stm32f401cdu6 same as is in espruino pico because exists precompiled dfu files.

[dhylands]

Personally, if I was going to stick with the 401, I would pick the STM32F401RET6 because it has more flash.

The images created for the Espruino will still work, but the Espruino Pico flash is very close to being full. Actually, it looks like it has already overflowed.

I just built using the latest and I see:

Code: Select all

2004 >arm-none-eabi-objdump -h build-ESPRUINO_PICO/firmware.elf 

build-ESPRUINO_PICO/firmware.elf:     file format elf32-littlearm

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .isr_vector   0000272c  08000000  08000000  00010000  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  1 .text         000400d8  08020000  08020000  00020000  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  2 .data         00000108  20000000  080600d8  00070000  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  3 .bss          00006428  20000108  080601e0  00070108  2**2
                  ALLOC
  4 .heap         00004000  20006530  080601e0  00076530  2**0
                  ALLOC
  5 .stack        00000800  2000a530  080601e0  0007a530  2**0
                  ALLOC
  6 .ARM.attributes 00000035  00000000  00000000  00070108  2**0
                  CONTENTS, READONLY
  7 .comment      000000de  00000000  00000000  0007013d  2**0
                  CONTENTS, READONLY

The .text section being 0x400d8 means that 0xd8 bytes won't fit.

The Espruino Pico only has 384K flash, where the STM32F401RET6 has 512K flash.