tiny stm32 F4 boards

Limited support for STM32F4 Discovery, Nucleo and custom F4 boards
Ollie
Posts: 197
Joined: Thu Feb 25, 2016 7:27 pm

Re: tiny stm32 F4 boards

Post by Ollie » Mon May 22, 2017 3:03 pm

I have not yet accessed the content of the EEPROM - my expectation is that it is empty. Because there is the SD drive, the EEPROM is not the only way to store application data.

I like your ideas about the long Dupont pins on both sides. For development and debugging that is the best way. For deployment, I do recommend the round machine pins. With the female Dupont headers, the cutting to proper length is frustrating. My method is to use bandsaw and a sander. With machine pins, the cutting can be done with pliers in the same way as the male headers are adjusted. If you are using white female machine pin headers, you can use color markers to identify the pin locations.

It would be nice if this board would gain popularity due its small size, nice functionality, high performance, and low cost. That would increase its support and further popularity.

ag123
Posts: 795
Joined: Thu Jul 21, 2016 4:24 pm

Re: tiny stm32 F4 boards

Post by ag123 » Mon May 22, 2017 9:36 pm

agreed the long pins is an interesting/useful idea. on a side note the smd components and the chip/soc itself is rather easy to damage say if it is rubbed against a surface. the long pins would help in that case, but i'm thinking how to put this in some frame or enclosure, it is somewhat harder as the board do not seem to have screw mounting holes, similar to maple mini. probably would be looking for some solution.
i'm thinking of using styrofoam (Polystyrene) to plug the pins in, just that i'm not too sure if styrofoam boards may create static electricity that perhaps cause some shorts. but using say stoyforoam may be a good way to hold the board say in place in a case say without the mounting screws

oh by the way the manufacturer/originator web site apparently have various info such as schematics etc, they are in chinese though.
but the symbols, part numbers etc would pretty much be in alphabets, you could try putting the urls in google translate if it helps to make sense of the web
http://www.vcc-gnd.com/
http://www.vcc-gnd.com/cp/stm32hxb/stm32f4xxhexinban/

someone has uploaded various info and schematic into the wiki as well
http://wiki.stm32duino.com/index.php?ti ... 7VET6_Mini
http://wiki.stm32duino.com/images/6/69/ ... ematic.pdf

my guess too about the eeprom is it is likely to be uninitialised, normally it is rather popular to store some info in eeprom to identify the board. this could help the firmware tell what board it is running on as it would otherwise be indistinguishable. but i doubt such info is stored in the eeprom, in particular across all the same boards

palmerr
Posts: 58
Joined: Tue Jan 31, 2017 6:21 am
Location: Melbourne, Australia

Re: tiny stm32 F4 boards

Post by palmerr » Tue May 23, 2017 1:03 am

A 3d printed frame would be the obvious answer!

Just a simple box with a lip inside for the edge of the board to sit on - for a top mount solution.

Image

For a slide-in solution, a slot below the top edge could work.

Image

Richard

Ollie
Posts: 197
Joined: Thu Feb 25, 2016 7:27 pm

Re: tiny stm32 F4 boards - how about AnyFC-F7

Post by Ollie » Fri May 26, 2017 6:15 pm

I am tempted to get a F7 based helicopter flight controller from Aliexpress https://www.aliexpress.com/item/AnyFC-R ... 17566.html for $32.

My hold-back is that I am still learning the best practices for F4 CubeMx HAL and not yet ready to jump into F7. My temptation is increased with the new technology for fast control. Instead of doing hundreds of PID loops per second, the new race controllers are doing thousands of PID loops per second. The classic analog servo signal (1 .. 2 ms) is too slow and inaccurate for that. It is replaced with digital DSHOT protocol where the microsecond level pulse streams are driven with DMA channels between the host and Electronic Speed Controller. Perhaps DSHOT will be used also for the coming fast servos :?:

I will jump to the multimotor BLDC motor control using DSHOT600 (or perhaps DSHOT1200) with F407VE based main controller. The Racestar RS20Ax4 at Aliexpress https://www.aliexpress.com/item/New-Arr ... 42226.html for $34 is a good price for 4 motor controller with 5V regulator for the main board. I did order that with four gimbal motors for robotic application.

If the next revision of AnyFC F7 mini board will have MPU9255 instead of the classic MPU6000, I would purchase it now for evaluation. 8-)

ag123
Posts: 795
Joined: Thu Jul 21, 2016 4:24 pm

Re: tiny stm32 F4 boards

Post by ag123 » Fri May 26, 2017 7:08 pm

f7 is probably closer to a raspberry pi / beagle bone black (i.e. mini PCs) than simply f4, f1 which is deem an 'mcu', i've been wondering how they have been able to pack that much stuff into an soc, as the photos goes, the f7 do have a 'massive' chip surface :lol:

i've been looking at those f103vet/zet vs f407vet/zet, apparently the price differential between the f3 vet/zet vs f4 vet/zet is not as large as say compared to a blue pill / maple mini $2. given the significantly higher performance + the increased ram + flash + additional soc resources (e.g. fpu), i decided to just go with f4, would probably look at f7 another time :)

Ollie
Posts: 197
Joined: Thu Feb 25, 2016 7:27 pm

Re: tiny stm32 F4 boards - size comparison

Post by Ollie » Fri Jun 02, 2017 7:27 pm

Here are two pictures to illustrate the sizes of
  • STM32F745VGT6, the small flight controller
  • STM32F407VET6, the handy blue board I am using in a multi-motor controller
  • STM32F407VGT6, the nice black board for medium size vanilla applications
Image
Top view

Image
Bottom view. Here you can see the machine pins used in lieu of the square pins.

The F7 board was designed by Sami Korhonen (sambas) in 2016 and it is really nice with very compact cabling to UART and other peripheral devices. First, I criticized the usage of MPU6000, but for practical terms this 6 DOF IMU is adequate for my robotic applications.

Cheers, Ollie

PS. Sorry for my mistake in sharing - it was private and the public view was not enabled :oops:
Last edited by Ollie on Sat Jun 03, 2017 1:06 am, edited 1 time in total.

stevestrong
Posts: 1811
Joined: Mon Oct 19, 2015 12:06 am
Location: Munich, Germany

Re: tiny stm32 F4 boards

Post by stevestrong » Fri Jun 02, 2017 8:47 pm

I see no images :roll:

Post Reply