Red/Blue pill with GD32F103CBT6

I don’t know if it’s a silly idea (or not ) , but:
I am planning to perform brain surgery on a red/blue pill: replace the microcontroller with a GD32F103CBT6.
Which board would you recommend: red pill or blue pill (I have read the topic on the comparison of the two)?
Besides replacing the 8MHz quartz crystal with a 12MHz one, are there any other changes required?

Thanks!

Buy one of each and decide for yourself. They are so inexpensive, no need to waffle.

Rick Kimball wrote:Buy one of each and decide for yourself. They are so inexpensive, no need to waffle.

cazimirb wrote:Rick Kimball wrote:Buy one of each and decide for yourself. They are so inexpensive, no need to waffle.

Blue pill with GD32F103CBT6 and 12MHz crystal works ok. Tested with GD32duino bootloader and 120MHz clock.

I tried to put a GD32, taken from one board, onto a Maple mini, but my soldering was not good enough, and I basically destroyed

shame really, as it would have been interesting.

I should have cleaned the Maple mini very carefully first to remove and bumps of solder on the pads, and likewise with the GD32 chip from the other board.

But I know from past experience, these boards are not rugged enough to have more than one or two attempts to get the chip off the board and put another in its place, as the pads seem to come loose from the PCB quite quickly

Taking out the old STM32 chip was pretty easy, using the hot air gun..but putting the new GD32 chip in place was quite difficult in terms of pin alignment..I tried to avoid as much as possible using a soldering iron..and put it at 300C..
The GD32 chips I bought from taobao for something like $1.5 a piece..

I was using a GD32 from another board, so it hard traces of solder on it.

I guess if I did it again, and made sure I got rid of as many small blobs of solder as possible it would be OK

Incidently I was thinking of ordering some STM32F103C8’s from AliExpress, so perhaps I should take a chance and get some GD32’s instead

But I’ve given up on Taobao, after I had a major screw up with my order, and ended up with twice as many boards as I wanted (albeit it was my fault as I didnt understand YoyBuy’s terrible UI with multiple purchasing options) – but I also got slugged an extra $10 as they decided to put one of the orders in a heavy cardboard box, where as one came in an envelope, and there was 1 board missing….

I think I’ll stick to AliExpress.

BTW.

Do you think the package / pin alignment is actually different, or just difficult to align ?

RogerClark wrote:

I think I’ll stick to AliExpress.

BTW.

Do you think the package / pin alignment is actually different, or just difficult to align ?

cazimirb wrote:RogerClark wrote:
<…>
but keeping the physical alignment is difficult, because of the solder bumps.

Hi Ray

The bumps were a product of me not being able to remove all the solder from the pads on the Maple mini, and also not remove all the solder from the GD32 i removed from another board.

If I had a bare Maple Mini pcb and brand new GD32 this would not be an issue and i could just reflow it using my hot air tool.

I didn’t remove the solder from the pads, just applied flux and ‘re-distribute’ the solder uniformly with the soldering iron.
You’re right Roger, having a bare board and a brand new chip would make it easier to solder.
BTW, just got a working red pill using the same procedure as for the blue pill.

I can’t quite remember what happened, but I think I damaged one or two of the pads on the Maple mini while trying to position the GD32, so I had to throw the board away

RogerClark wrote:..I think I damaged one or two of the pads on the Maple mini..