A new small STM32L4 board

[FRDM4236]

Hi All,
I remember that a few years ago, there was a community effort to make a STM32F4 board in Blue Pill form factor. What is the latest information on that project?

I am thinking about making a small low power L4 board as an open source project.
Recently I made a Teensy 3.2 board smaller at 31mm x 13mm. You can download SCH, BOM and Gerber files at the following link:
https://www.pcbway.com/project/sharepro ... board.html

On the Teensy forum, someone suggested making a smaller TinyPICO. After evaluating the TinyPICO, I am sure that I can make it.
https://forum.pjrc.com/threads/68613-Mi ... x 12-98mm. I have been working on it very hard.
Is there any experienced ESP32 programmer interested in collaborating and testing it?

I think that I may be able to make something like that for the STM32L4 after I shrink the TinyPICO.
Is anyone interested ?
Thank you very much!
Happy Thanksgiving to all!

[mrburnette]

Hi All,
I remember that a few years ago, there was a community effort to make a STM32F4 board in Blue Pill form factor. What is the latest information on that project?
...

Origional thread: https://stm32duinoforum.com/forum/viewt ... _2633.html

I think some members actually made bluepill sized F4 boards, but the availability of Chinese F4xx at a reasonable price dampened the forum effort. I remember at least 1 member mailing out a few "extra" custom boards for eval. But I can not remember any large forum purchase opportunity.

https://stm32duinoforum.com/forum/viewt ... t_110.html

[ag123]

it is good effort to try making a new board
L4 is actually more 'advanced' than F4 as they likely have some 'extra' low power peripherals that you may not find on F4.
for some existing 'example' boards, you could take a look here
https://stm32-base.org/boards/

the PYboard for MicroPython that has been around for quite some time qualifies as a mini board
https://store.micropython.org/
then Adafruit made one as well
https://www.adafruit.com/product/4382
then some others at olimex et.al
https://www.olimex.com/Products/ARM/ST/

[FRDM4236]

Thanks mrburnette and ag123 for the info.
I am very sorry that I have not gotten a chance to respond, I have been working very hard to finish shrinking the TinyPICO. The PCB layout is done and I will get the assembled prototype in 2 weeks. See the link at PJRC forum: https://forum.pjrc.com/threads/68890-Sh ... e-TinyPICO

I plan to make a L452 board soon, the reason I pick up the L452 is because a university is using our trainer with the L452. Since there is not much interest in this forum, I will collaborate with them. The size of the board may be larger depending on the features they want.

I think that this forum has discussed more hardware than the PJRC forum, mainly because this is a 100% open source forum.
So I have a question to ask. In the process of making a smaller ESP32 board, I found that battery charge status LED on the TinyPICO flashes even the battery is not connected. It's a bit annoying. I would like to stop it. With a good luck I think that I have found a solution. A simple LPF works on the paper, but I have to test it on my prototype. Can any one find any reason it may fail?
https://forum.pjrc.com/threads/68945-A- ... PICO-board

Thank you very much.