Newbie Question: STM32F103 or newer equivalent for new project?

[Grant Bt]

So the Blue Pill guy checks almost all the boxes for a new project I'm working on soon. 3 UARTS, M3, 72MHz, USB device, cheap, powerful *but* I'm not clear on the "fix" for being able to re-enumerate my device on USB. I must be able to change device types under firmware control (host re-enumerates device from say CDC to MSD or whatever). I've seen comments about workarounds and adding external transistors, but I don't know really how to do it. So, any pointers please.

Alternatively, I could use something newer if it checks all the same boxes (not substantially slower for instance) and is within $1USD of the F103 at 1k quantities. Recommendations? I have spent way too long on the Product Selector that I feel I need human input here. I don't need low power, FPU, DSP, but if they are there that's fine.

Thanks!

[heifetsg]

That actually depends on your requirements.

[Peter BENSCH]

STM32F103 is fine and will be available at least 10 more years (see 10 Years Product Longevity).

But of course you can select whatever you want - it just depends on your preferences for core and/or package and/or peripherals, etc.

When your question is answered, please close this topic by choosing Select as Best.

/Peter

[Tesla DeLorean]

Got several complaints in recent days of F1 and F0 parts pushing out beyond 26 weeks, no distributor stock and ST not taking orders.​

​

I​t is no good claiming 10 year support and then poisoning the well with no or insufficient availability. Designers burned this way have very long memories.

[Grant Bt]

Yeah curiously I was looking at stock in the US and noticed a lot of 60-days-out kind of thing. Brought back memories of the "on allocation" days.

[Grant Bt]

Hi. Thanks I updated my post with more info. First time posting here, so I made a mistake.

Any thoughts on how to implement the USB re-plug requirement? On my previous micro I had a way of "disconnecting" USB by disabling the bus pull-up and then rebooting in order to cause host to re-enumerate the device. I'm not sure how to pull that off on the F103. It has to be rock solid.

[Tesla DeLorean]

I wouldn't design new product with F1 parts. Look at L4 parts, or perhaps Value Line products in the F7 or H7 space where you have paths and alternatives to upgrade later.

​

Look at CM0 parts if those are sufficient, the L072CZ having quite a lot of FLASH, RAM and USB support.​

[Grant Bt]

I think M0 parts at 48MHz is going to be quite a step down from M3 at 72MHz, non? I don't have a ton of experience here, but just on cursory observation it seemed so. Why is there so much stuff going M0? (I was just playing with the M3's SWV/SWO and found that a great development feature.)

[Grant Bt]

I did find out some information about the USB re-enumeration scenario, but I will have to test it out.

https://community.st.com/s/question/0D50X00009XkY1uSAF/stm32f103-usb-circuit

[frackers]

Rather than 'Blue Pill', take a look at 'Black Pill' which has a choice of f401 or f411. Make sure to get the latest V3 PCBs, there are a lot of sellers flogging off older versions.

BTW: The last Blue Pills I got had fake f103 on them - took a lot of time to find the ID so the debugger would work and I'm still not convinced they have duplicated all the RTC 'features'.

[Grant Bt]

Thanks. That's interesting. I only used the Blue Pill as a minimal get-to-know the part (rather than the NUCLEO which I do have also). The F401 looks interesting and it seems "more" than the F103 and is cheaper. I'll have to double-check that though. Mouser comparison @Q1k for 128k at LQFP64:

STM32F103RBT6 M3 72MHz $3.11 
https://www.mouser.com/ProductDetail/STMicroelectronics/STM32F103RBT6?qs=bhCVus9SdFv12dJRZaBmJg%3D%3D
 
STM32F401RBT6 M4 84MHz $2.51 
https://www.mouser.com/ProductDetail/STMicroelectronics/STM32F401RBT6?qs=4ccVDqXDOrn4COlKBEB%252BDA%3D%3D

I found the Canaduino Blue Pill boards genuine and correct and they have a Black PIll one too.

[Uwe Bonnes]

I very much like the STM32L41/3 these days. More space and better peripherals than F1 and similar prices. For small board lot at Nucleo-32. More expendive than xxPill but with garanteed genuine STM32 and built in debugger.

[Grant Bt]

Thanks. I'm numb from the possibilities. These are top candidates so far, but I also want to make sure that I start with something popular/common rather than an obscure variant that has less of a knowledge base or price competitiveness. Probably I will use QFP48 or QFP64, and flash of at least 128k or 256k.

STM32F103RBT6 M3 72MHz 128kFlash

STM32F401RBT6 M4 84MHz 128kFlash

STM32L433RBT6 M4 80MHz 128kFlash

STM32F411RCT6 M4 100MHz 256kFlash

USB Device and 3+UARTs again are also essential, along with performance similar to these above. I long for the days of the FAE (field application engineer) visits.

GB

[Uwe Bonnes]

STM32L433RBT6 has the modernest set of peripherals, F103 the oldest and fewest RAM.