Arduino for STM32

I built a couple, with F1, F4 and F7 MCUs.
Anyone still using and improving on them?
I have seen the F4 mini boards in aliexpress, but they each seem to have different pinouts.

Yep, I've made a few custom boards including an F405RG, the MCU's are pretty cheap on ali so...

is it difficult to hand solder stm32 mcus? i've been thinking about this option since those cks32f103 clones seemed to be getting more prevalent.
but of course these days there are stm32f401 & f411 boards
https://www.aliexpress.com/wholesale?ca ... =stm32f401.
and they are priced rather close to what the maple mini clones used to cost
thanks to stevstrong for adding support for them
it gives me a feeling that the f401 and f411 may be a next step in the 'evolution' of the 'pill' boards

I remember years ago when Ray posted about the $4 maple boards on aliexpress. Now the F4 board are that price.
The only problem I see with those, is that they have different pinouts vs the original bluepill and maple mini. The bluepillF4 designed in the old forum was pin compatible for the most part, which I really like.

ag123 wrote: Thu Dec 19, 2019 6:49 am is it difficult to hand solder stm32 mcus? i've been thinking about this option since those cks32f103 clones seemed to be getting more prevalent.
but of course these days there are stm32f401 & f411 boards
https://www.aliexpress.com/wholesale?ca ... =stm32f401.
and they are priced rather close to what the maple mini clones used to cost
thanks to stevstrong for adding support for them
it gives me a feeling that the f401 and f411 may be a next step in the 'evolution' of the 'pill' boards

For hand solder, if you use extra flux, yes, it's pretty easy even with home-made boards (with no solder mask), if you use a proper PCB should be even easier. They're other tools than can help you a bit on the task but you can get away without them:

• Thermally controlled solder station.
• A flat tip (I use the "C2" tip like 95% of the times).
• A magnifier glass (A digital microscope will be cool and some are at 40-60usd with internal battery and a small monitor).

Check this channel: https://www.youtube.com/channel/UCKDfmG ... 6hg/videos
It has nice tutorials on how to solder the most common packages and using a few methods, it's as easy as it seems, you just need flux.

There is also other options: using a hot air gun or an solder oven.

Cheers.

ag123 wrote: Thu Dec 19, 2019 6:49 am is it difficult to hand solder stm32 mcus? i've been thinking about this option since those cks32f103 clones seemed to be getting more prevalent.
but of course these days there are stm32f401 & f411 boards
https://www.aliexpress.com/wholesale?ca ... =stm32f401.
and they are priced rather close to what the maple mini clones used to cost
thanks to stevstrong for adding support for them
it gives me a feeling that the f401 and f411 may be a next step in the 'evolution' of the 'pill' boards

"Difficult" + soldering == personal experience.
I do not think it is difficult, but as I near the 70 YO mark, it is definitely more challenging and I cuss a lots more. As a teen, I rebuilt watches using only a $1 magnifying glass; but, I need a stereoscopic microscope these days to change a battery in my watch.

I have one of those $79 digital microscopes: not as great as you might think. Better than today's $1 magnifier, however. An old, used student 10x binocular microscope with decent optics is far superior IMO.
At $4 - $4.79 delivered, this could be a best-buy. But, while the advantages are there, most users will not require the enhancements ... only clock (speed) will be the obvious gain. Most users burn cpu cycles in loop{}, so the under $2 STM32F103 may still be the best for most Arduino users: well documented, lots of s/w, years of integration into Arduino.

Ray

Hi Guys

Frederic sent me a link to the new site

I bought one of those F411 boards a few weeks ago, for a project which needed more CPU power

https://www.aliexpress.com/item/4000103610226.html

The board looks OK, and is slightly smaller than the BluePill

But I don't know if it works, as I've been too busy even to load a bootloader onto it.

for this board one of the design elements i liked is the designer/vendor made boot0 a push button. while apps can't use it, but when flashing firmware, one can simply press that button, reset and flash away. resetting it next reverts to the normal mode. and as it is a f411 chances are that it is DFU flashable, hence all it takes is a usb cable and pressing that button.

rogerclark wrote: Fri Dec 20, 2019 3:36 am Hi Guys

Frederic sent me a link to the new site

I bought one of those F411 boards a few weeks ago, for a project which needed more CPU power

https://www.aliexpress.com/item/4000103610226.html

The board looks OK, and is slightly smaller than the BluePill

But I don't know if it works, as I've been too busy even to load a bootloader onto it.

I had bought some of these F401's too. It's a very good board!
https://mcu.selfip.com/viewtopic.php?f= ... ffe5#p1199

However, I have not tried the F411 version

ok finally i ordered a couple f401, cos it seem like 'everyone else has it'
the f411 seem to have SD hardware support, f401 nil
f4* and even f303cc doesn't feel the same as the stm32f103, they are faster even for the same clock speed

according to the flyer, and specs it has that ART accelerator and FPU !
https://www.st.com/resource/en/flyer/flstm32f4x1.pdf
oh & st's flyer says the uart can do 12.5 Mbps, i2c 1Mbps, only pity that we'd still only have a full speed usb
spi 50Mbps, i kind of wish my PC has a SPI port after all that is nearly 4x faster than full speed usb
(oh it seem it is there the intel chipset specs has it, i'd need to inspect my motherboard for unused pins)
seem like no dac on both f401 and f411, some other sku in the 41x series has it, probably cost more


back then one of those fun things we tried in the old stm32duino forum is to run the
https://en.wikipedia.org/wiki/Dhrystone
and
whetstone benchmark
https://en.wikipedia.org/wiki/Whetstone_(benchmark)
on stm32f407, pito achieved 500 mflops on an mcu overclocked to 250mhz, that is almost 2 flop per clock
and is the unbeaten record holder trying to get as many flops out of these little mcus
if you have that board, you may want to try rev up the 'engine' to see how many flops you'd get, the 'old' source codes attached
stm32f103 is very far behind especially when it comes to floating point due to the double speedups from art accelerator (0 wait state execution from flash - pretty much a fast cpu cache) and the fpu

some of the schematics, layouts etc for that board, i've uploaded some copies of that found from a vendor repository
it is currently in a thread on mcu.selfip.com
https://mcu.selfip.com/viewtopic.php?f=25&t=138&p=1199