VCC-GND STM32F407VET6 dev board

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VCC-GND STM32F407VET6 dev board

Postby mcauser » Thu Jan 12, 2017 6:12 am

So, I've purchased one of the STM32f407VET6 dev boards from a company called vcc-gnd with a goal to porting MicroPython to it.
I have a pyboard 1.0 with a STM32f405, which is in the same family, so it shouldn't be too hard to port across.


Does anyone else have one of these boards?
Same provider also sells STM32F103C8T6 "Blue Pill" boards, which I am also interested in experimenting with.

Why not just get another pyboard? Because they are like $60-80 AUD incl. shipping and this board is only $11 USD with free shipping!
I'll run the risky code on the cheap board and if it breaks, no big deal. It's also a learning experience in the uncharted world of STM32. ... 85751.html
$11 USD

The board I purchased was from TaoBao, and thanks to a Chinese-English translation error, I had to pay $15 in shipping... twice! Once from the supplier to their Chinese warehouse and again over to Australia. I'll stick to AliExpress now.
¥53 ($11 USD)

STM32f407VET6 ARM Cortex M4
168MHz, 210 DMIPS / 1.25 DMIPS / MHz
1.8V - 3.6V operating voltage
25MHz system crystal (NX5032GA)
32.768KHz RTC crystal
AT24C08 I2C EEPROM 1024 Byte x 8, 400KHz
2.54mm pitch pins
JTAG/SWD header
512KByte Flash, 192 + 4 KByte SRAM
3x SPI, 3x USART, 2x UART, 2x I2S, 3x I2C
1x FSMC, 1x SDIO, 2x CAN
1x USB 2.0 FS / HS controller (with dedicated DMA)
1x USB HS ULPI (for external USB HS PHY)
Micro SD
1x 10/100 Ethernet MAC
1x 8 to 12-bit Parallel Camera interface
3x ADC (12-bit / 16-channel)
2x DAC (12-bit)
12x general timers, 2x advanced timers
RT9193-3.3V: 3.3V LDO voltage regulator, max current 300mA
Micro USB for power and comms
User LED (PB9)
2x DIP switch for bootloader selection
Reset button
2x18 side pins + 2x10 top pins + 1x4 debug pins

change HSE_VALUE from 8000000 to 25000000
change PLL_M from 8 to 25

So far I have a butchered version of 1.8.6 running, based on OLIMEX_E407 and STM32F4DISC.
Will keep you posted with my progress and make a PR once it's reasonably stable.

Is VCC_GND_STM32F407VET6 a reasonable board name in /stmhal/boards/?
Last edited by mcauser on Thu Jan 12, 2017 7:30 am, edited 1 time in total.

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Re: VCC-GND STM32F407VET6 dev board

Postby dhylands » Thu Jan 12, 2017 6:44 am

Looks like a nice little board. It's cheaper than I can buy the raw processor.

I've previously bought a few of the STMF103 boards to play with. They aren't big enough to run MicroPython on, but you can program them in C. If you're interested, I have a sample project here: that includes some files to build a simple LED blinker.

You'll find some more information (including how to flash a USB DFU bootloader onto the '103 here: ... 2F103-Mini

I'd probably simplify the board name to just VCC_GND_F407 (but that's just my personal preference).

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Re: VCC-GND STM32F407VET6 dev board

Postby marfis » Thu Jan 12, 2017 9:07 pm

Why not just get another pyboard?

yeah - well then at least support Damien with a couple of stickers:

it's definetly a nice board. Although the seller seems to think it's a voltage regulator (???)

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Re: VCC-GND STM32F407VET6 dev board

Postby mcauser » Thu Jan 12, 2017 11:02 pm

AliExpress product listings are well known to be incomplete, incorrect or missing. It's best to find at least 3 vendors selling the same thing and average the descriptions :)

I'm more likely to send Damien, Paul and the team cold hard cash or bitcoins than to buy stickers from a 3rd party vendor.
I am supporting the team, with contributions, promotion and community engagement. And later, I'll most likely back their next kickstarter.

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Re: VCC-GND STM32F407VET6 dev board

Postby mcauser » Fri Jan 13, 2017 3:54 am

It Works!

Instructions for OS X:

Install packages
$ brew install stlink
$ brew cask install gcc-arm-embedded

Check if ST-LINK V2 device is found
(plug it into USB port)
$ st-info --probe
Found 1 stlink programmers

Connect ST-LINK V2 to VCC-GND STM32F407VET6 dev board
3.3V --- 3v3
GND ---- GND

Open two terminals, one for st-util and the other to compile and upload.

Open the first terminal and run
$ st-util
It should say "Listening at *:4242..."

Open the second terminal and run:
$ cd micropython
$ git remote add mcauser
$ git fetch mcauser
$ git checkout vcc-gnd-stm32f407
$ cd stmhal
$ make BOARD=VCC_GND_F407
$ arm-none-eabi-gdb build-VCC_GND_F407/firmware.elf

Inside gdb run:
(gdb) target extended localhost:4242
(gdb) load
(gdb) exit
LEDs will blink as the firmware is uploaded.

Switch back to the st-util terminal
Look for "Flash written and verified! jolly good!"
Ctrl+C to exit

Disconnect ST-LINK from USB
Disconnect ST-LINK from dev board (3V3,SWDIO,SWCLK,GND)

Run MicroPython on the board
Connect to the dev board using USB cable (make sure ST-LINK is disconnected to avoid blue smoke)
$ screen /dev/tty.usbmodem1422 115200
to exit: Ctrl+a Ctrl+\ y

Code: Select all

MicroPython v1.8.7-4-g51a4473-dirty on 2017-01-13; VCC-GND STM32F407 with STM32F407
Type "help()" for more information.


Code: Select all

  102016 total
  432 : 101584
  1=14 2=5 m=3
LFS free: 86528 bytes

The AT24C08 EEPROM on I2C1
>>> i2c = machine.I2C(1)
>>> i2c.scan()
[80, 81, 82, 83]

Toggle blue led
>>> led = pyb.LED(1)
>>> led.on()

>>> import gc
>>> gc.mem_free()
>>> gc.mem_alloc()

>>> pyb.rng()

>>> pyb.millis()

>>> rtc = pyb.RTC()
>>> rtc.datetime((2017, 1, 13, 14, 45, 0, 0, 0))
>>> rtc.datetime()
(2017, 1, 13, 6, 5, 0, 1, 204)

>>> adc = pyb.ADC(pyb.Pin.board.PA1)

Don't forget to eject the PYBFLASH USB device before unplugging.

Feedback welcome:

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