Bluepill with STM32F4

I love the formfactor of the bluepill, but sometimes wished it had a bit more power.
So… i ordered some stm32f401 & f411 chips, (and a hot air smd rework station XD), and gave it a try to get one of these nice processors on a bluepill .
(ok, a few tries :p)
STM is really good at keeping pin compatibility between their processors. all essential things (power supply, crystals & usb) are on the same pins on most processors (i did find an exception somewhere, always check with the cubemx tool). So i ordered a few of the 4 series chips that are also 48 pins to give it a try .
If you look up these microcontrollers, you’ll notice it’s not a QFP package, but QFN, which is pretty annoying to work with, but if my current attempt worked, then it’s quite doable with a hot air station. and the pads also extend to the side a bit, so if a pin isn’t soldered properly, you should be able to add some solder to it with a fine tip and a steady hand.

After getting to know my hot air station a bit, i now have a bluepill with a stm32f401ceu6 that i’ve been able to program, and that is blinking the bluepill led . Not sure yet how well my soldering job was and if all pins will work, but this is a good start XD.

Now could we somehow convince the chinese companies making bluepills/maple minis to make these? imagine being able to buy the likes of this for < 10$ XD.

If everything is succesful, this little bluepill now has 2 DACS, 3 I2C ports, 3SPI ports (of which 2 can do I2S) and can also be a usb host, not just a device . And it can go to 84Mhz (and the spi ports are thus also faster ). And to top it off, 96kb ram, 512kb flash!

Thats super cool.

I wonder what the price difference is between teh F103C and the F401 (at 100 off quantities)

The manufacturer would probably be willing to make a batch of these, if there was sufficient order quantity e.g. 100 +

I wonder who makes the Black Pill (or the Blue Pill), as it may be worth us getting in touch with them and asking about a price.

first – oh why didn’t i … …

um, baite mini maple with a 401

any others the same type of substitution might work on/with?

on aliexpress, you’re swamped with all the nucleo-401’s offered
on the stm32f401ceu6 chip, 3-4ukp, farnell uk are listing 5.50 area

someone is offering 50 for £1950, i suspect there’s a missing zero typo in there, well i’d hope so.

stephen

the compatible chips are the stm32f401, 411, 412, 413 and 423
I’ve also got a few 413’s on the way from digikey (since i can’t find those on aliexpress).
The’re really insane 0_0 1.5Mb flash, 320kb ram, dacs, plenty of spi i2c i2s, you name it, sdio, usb host, …. it’s all there in that tiny chip that fits on a bluepill/maple mini /…
There usually is 1 small difference with the pinout of the stm32f103: they have one output pin less, because one of the pins you’re supposed to put a capacitor on for the internal reference voltage. but if not using that feature, you probably don’t even have to bother (and otherwise it’ll be like adding the bluepill parallel resistor for usb).
also if we’d convince a chinese factory to produce boards like this, they might want to swap out the qfp pad for something more suited for qfn . it fit’s on there, but it was not really made for it XD.

and you can indeed find some mucleo’s 401 on aliexpress etc… but it’s again a stupid uno sized board, and 20$ is just too much for such a clumsy thing >_<.
you can indeed find the 401 for about 4-5€, and the 411 for 5-6€ a piece, so making a modded bluepill/maple mini isn’t that expensive XD.

And a maple mini with the better chip is indeed also possible . In my previous dealings with the boards however (a while back i did the same with an stm32f303 on bluepill/maple mini) i noticed that the baite pcb is a bit more delicate to switch the microcontroller on. and since it costs a lot more, i stuck with bluepills from then on. With my SMD rework station it may work better now, i’ll give it a try (finally a usage for all the maple mini, bluepill, blackpill, … boards i’ve been hoarding XD)

racemaniac wrote:t
The’re really insane 0_0 1.5Mb flash, 320kb ram, dacs, plenty of spi i2c i2s, you name it, sdio, usb host, ….

ahull wrote:racemaniac wrote:t
The’re really insane 0_0 1.5Mb flash, 320kb ram, dacs, plenty of spi i2c i2s, you name it, sdio, usb host, ….

12-bit ADC reaching 2.4 MSPS

stm32f413_f423_image.jpg (36.5 KiB) Viewed 2070 times

F103 power has been ok for me but I’m running out of RAM

Would be awesome to get a board with BP form factor and F4!

what does the blue pill plus pin out diagram look like at the edges ?

a complete re-write or just a few pins ?

stephen

It seems like there are a couple of lqfp 48 parts available in the stm32l4xx line, the stm32l433cct6 and the stm32l443cct6. These don’t have as much ram or flash (64k/256k) but might be an easier replacement, * assuming the pin outs are the same * Both are a step up from the f103’s 20k

I wonder if you can just buy the bluepill pcb?

-rick

zmemw16 wrote:what does the blue pill plus pin out diagram look like at the edges ?

a complete re-write or just a few pins ?

stephen

Rick Kimball wrote:It seems like there are a couple of lqfp 48 parts available in the stm32l4xx line, the stm32l433cct6 and the stm32l443cct6. These don’t have as much ram or flash (64k/256k) but might be an easier replacement, * assuming the pin outs are the same * Both are a step up from the f103’s 20k

I wonder if you can just buy the bluepill pcb?

-rick

I tried upgrading a Maple mini to a GD32 some time ago, but as the GD32 was removed from another board, it had a tiny bit of solder on it, and I ended up damaging the Maple mini by pulling a track off the PCB when I tried to position the GD32

So Its probably best to do this upgrade on the cheapest board e.g. Black Pill and not using a salvaged STM32

RogerClark wrote:I tried upgrading a Maple mini to a GD32 some time ago, but as the GD32 was removed from another board, it had a tiny bit of solder on it, and I ended up damaging the Maple mini by pulling a track off the PCB when I tried to position the GD32

So Its probably best to do this upgrade on the cheapest board e.g. Black Pill and not using a salvaged STM32

I think I’ll order some more Black Pill’s as they have a better USB connector, as I’ve already broken the usb connector on 2 x Red Pills in the last year.

RogerClark wrote:I think I’ll order some more Black Pill’s as they have a better USB connector, as I’ve already broken the usb connector on 2 x Red Pills in the last year.

i’ve done some more experiments with replacing chips:
for me the bluepill is the only option. The maple mini has tiny pads that are only suited for qfp, not for qfn… and the blackpill has a lot of smd components near the microcontroller… it could work, but you’ll have to fix up all the tiny resistors/capacitors afterwards >_<

*edit* after some testing i’ve noticed that if i put the 401 in a higher clockspeed, it often crashes while setting up the clock. i’m going to have a look at if it has to do with the VCAP pin that isn’t connected yet. at 24Mhz it’s running stable, at 72Mhz it often crashes.

Ok, after some waiting for the bigger value ceramic capacitors to arrive from china, i finally continued with this project, and i’ve got some great news
After adding the required capacitor (4.7µF between PB11 & ground, and yes it HAS to be ceramic), my bluepill with the stm32f411CEU6 is now running stable at 96Mhz . (basically the fastest it can go. it’s rated to 100Mhz, but then USB won’t work as you can’t configure a 48Mhz clock).
So if you want to go for a stm32f411 bluepill, it’s possible and it works .

I’ve yet to do more extensive tests with this little beast, but all signs are starting to point to the fact that this works :p.

what package were the ceramic caps ? leads or smd
any convenient cap to replace and / or rewire the pads

is that PB11 the bluepill pin on the pcb, or pb11 on the cpu or something entirely different ?

any other mods needed ?

stephen

zmemw16 wrote:what package were the ceramic caps ? leads or smd
any convenient cap to replace and / or rewire the pads

is that PB11 the bluepill pin on the pcb, or pb11 on the cpu or something entirely different ?

any other mods needed ?

stephen

I’ve been using it a bit more yesterday, seems to be working well
i’m experimenting with its i2s hardware, and it’s also working . (but my i2s chip i’m using isn’t >_<. it’s going to drive me crazy :p ).
ah well, i’ve got a couple of others to try with too, mission for the weekend: get A i2s DAC properly working :p.

Rick Kimball wrote:It seems like there are a couple of lqfp 48 parts available in the stm32l4xx line, the stm32l433cct6 and the stm32l443cct6. These don’t have as much ram or flash (64k/256k) but might be an easier replacement, * assuming the pin outs are the same * Both are a step up from the f103’s 20k

I wonder if you can just buy the bluepill pcb?

-rick

racemaniac wrote:I’ve been using it a bit more yesterday, seems to be working well
i’m experimenting with its i2s hardware, and it’s also working . (but my i2s chip i’m using isn’t >_<. it’s going to drive me crazy :p ).
ah well, i’ve got a couple of others to try with too, mission for the weekend: get A i2s DAC properly working :p.

racemaniac wrote:racemaniac wrote:I’ve been using it a bit more yesterday, seems to be working well
i’m experimenting with its i2s hardware, and it’s also working . (but my i2s chip i’m using isn’t >_<. it’s going to drive me crazy :p ).
ah well, i’ve got a couple of others to try with too, mission for the weekend: get A i2s DAC properly working :p.

victor_pv wrote:racemaniac wrote:racemaniac wrote:I’ve been using it a bit more yesterday, seems to be working well
i’m experimenting with its i2s hardware, and it’s also working . (but my i2s chip i’m using isn’t >_<. it’s going to drive me crazy :p ).
ah well, i’ve got a couple of others to try with too, mission for the weekend: get A i2s DAC properly working :p.

there is a thread on ‘tiny’ stm32f4 boards here
http://www.stm32duino.com/viewtopic.php?f=39&t=1977
as well

one of the smallest and well designed development boards with many pins broken out is possibly the micropython boards
https://store.micropython.org/#/products/PYBv1_1
various other boards is reviewed in the ‘tiny stm32f4’ boards thread above

for the f4 (f405, f407) boards, i think the soc itself makes up the bulk of the cost itself as it is after all a rather complex and rather large soc ( compared to the f1) default config with 196k sram and 512 – 1m flash

oh from ST itself!
http://www.st.com/en/evaluation-tools/n … 432kc.html