GD32F103 ?

You might have heard of that one or not : The  GD32F103C8T6 MCU

What is it ?
It is a alternative (i.e. compatible) chinese MCU to the STM32F103C8T6 as found on the bluepill.
It is cheap (1.5$) , but so is the STM32 (about the same price)

Why bother ?

First, for the fun of it :).
Second, it can run faster (108 Mhz)
Third it has a DAC, that the STM32F103 lacks, could be very handy for the component tester

So i removed a STM32 from a bluepill and put a GD32 instead (nb: That board had ADC problem prior to sacrificing it).

Same software as with the STM32F103, zero change whatsoever.

and.... drum roll....

* Boot ok !
* SPI ok !!
* GPIO ok !!!
* USB ok !!!
* ADC : Fail !

Bummer
So far, it looks like a really compatible  chip, drop in replacement for most things.
The verdict is still out concerning the ADC, maybe the bluepill board is acting funny or i overheated the chip when soldering it back (i had ADC problem with the older chip on the same board)


The basic test failing (and yes, this is prototype1 of the component tester), worth ~ 10$

GD32 soldering is not too shabby



Important:

It is most probably not ok to use software from ST and run it on a GD32 or any other compatible chips.
To experiment / personal use, no real issue, but never ever sell a product with ST library and GD32 chip.
GigaDevice does provide a SDK though.

I'll retry next time i fry I2C or SPI on a bluepill, should not take too long.

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