Guide for under- and over-clocking the blue-pill needed

Post here first, or if you can't find a relevant section!
edogaldo
Posts: 254
Joined: Fri Jun 03, 2016 8:19 am

Re: Guide for under- and over-clocking the blue-pill needed

Post by edogaldo » Mon Jan 09, 2017 8:22 am

RogerClark wrote:[...] and that version does not have a CLI, or take binary files (arrrgghhh)
Hi Roger, just checked and it seems the STM's DFU has a CLI.
It's named "DfuSeCommand.exe" and it's located in the same path of the "DfuSeDemo.exe".
Need to understand how to use it..

[EDIT] maybe also this link can be useful: https://hackaday.io/project/4139/instructions

User avatar
Pito
Posts: 1498
Joined: Sat Mar 26, 2016 3:26 pm
Location: Rapa Nui

Re: Guide for under- and over-clocking the blue-pill needed

Post by Pito » Mon Jan 09, 2017 8:33 am

stevestrong wrote:..Because I tried to toggle one GPIO pin at different flash wait states (0, 1 and 2) here.
..
Try to disable prefetch in (your link above):

Code: Select all

 flash_enable_features(FLASH_PREFETCH | FLASH_ICACHE | FLASH_DCACHE);
and it might be you will start to notice the difference.
Pukao Hats Cleaning Services Ltd.

User avatar
Pito
Posts: 1498
Joined: Sat Mar 26, 2016 3:26 pm
Location: Rapa Nui

Re: Guide for under- and over-clocking the blue-pill needed

Post by Pito » Mon Jan 09, 2017 8:37 am

F407 - overclocking - I did in past (F4Discovery) but the chances for such an overclock like the F103 (1.77x) are minor.
The max I got was 210MHz (1.25x). Hopefully my Disco has got a crappy 407 chip on it and the others work higher :).
In the meantime there are F4xx at 200MHz standard speed. In the Q2 this year this
http://www.st.com/en/microcontrollers/s ... tId=SS1951
should be available, 400MHz.
Pukao Hats Cleaning Services Ltd.

User avatar
RogerClark
Posts: 6673
Joined: Mon Apr 27, 2015 10:36 am
Location: Melbourne, Australia
Contact:

Re: Guide for under- and over-clocking the blue-pill needed

Post by RogerClark » Mon Jan 09, 2017 8:50 am

edogaldo wrote:
RogerClark wrote:[...] and that version does not have a CLI, or take binary files (arrrgghhh)
Hi Roger, just checked and it seems the STM's DFU has a CLI.
It's named "DfuSeCommand.exe" and it's located in the same path of the "DfuSeDemo.exe".
Need to understand how to use it..

[EDIT] maybe also this link can be useful: https://hackaday.io/project/4139/instructions
Thanks, but I don't want to mess up @stevestrong's thread, which is supposed to be about overclocking ;-)
I think I may have started a separate thread about DFU on the F4

User avatar
RogerClark
Posts: 6673
Joined: Mon Apr 27, 2015 10:36 am
Location: Melbourne, Australia
Contact:

Re: Guide for under- and over-clocking the blue-pill needed

Post by RogerClark » Mon Jan 09, 2017 10:09 am

I've updated the core and pushed a change so that the generic F103C and the Maple mini can select CPU speed of 72Mhz or 48Mhz, both of which still maintain USB.

We could add more options for higher clock speeds, but USB will stop working, so I don't know whether its something that is worth adding to the core / boards.txt as it adds even more complication

I suppose we could add more #ifdef's for higher CPU speeds and if anyone wants them, they would just need to change their boards.txt file, but I don't know what RCC PLL multiplier are worth adding e.g. I don't see much point in adding a setting for 80Mhz or 88Mhz as this would not give a big speed boost, so it would need to be at least 96Mhz

stevestrong
Posts: 1502
Joined: Mon Oct 19, 2015 12:06 am
Location: Munich, Germany

Re: Guide for under- and over-clocking the blue-pill needed

Post by stevestrong » Mon Jan 09, 2017 10:38 am

That was my original idea: to have a place where it is shown what to do (step-by-step for dummies like me) if one needs to over(/under)clock...
This makes any further change in repo obsolete, even more because then the USB upload would be not functional, causing more headache then solving problems, as you said.
We could maybe add the collected info to a wiki page.

User avatar
Pito
Posts: 1498
Joined: Sat Mar 26, 2016 3:26 pm
Location: Rapa Nui

Re: Guide for under- and over-clocking the blue-pill needed

Post by Pito » Mon Jan 09, 2017 7:47 pm

I think for hobbyist it could be interesting to have those overclocking options in the menu, even when USB serial will not work.
The speeds 96, 128.
You may add to the menu description "(oclkd, noUSB)" or something like that.
The Q is how many do use USB serial actually.
Pukao Hats Cleaning Services Ltd.

User avatar
RogerClark
Posts: 6673
Joined: Mon Apr 27, 2015 10:36 am
Location: Melbourne, Australia
Contact:

Re: Guide for under- and over-clocking the blue-pill needed

Post by RogerClark » Mon Jan 09, 2017 7:57 pm

@pito

The problem with No USB, is that there is No Reset to upload.

I am sure that if overclocking with Reset not working, was on the menu, I would get all sorts of direct emails and bug reports on github, and messages via youtube.

So its safer to do as @stevstrong has suggested, and document how to overclock, but not put it on a menu where inexperienced users can select, something which makes their system non functional.

User avatar
Pito
Posts: 1498
Joined: Sat Mar 26, 2016 3:26 pm
Location: Rapa Nui

Re: Guide for under- and over-clocking the blue-pill needed

Post by Pito » Mon Jan 09, 2017 8:42 pm

The problem with No USB, is that there is No Reset to upload.
Yes, that I noticed too - I wanted to shot an utube video on the issue, but then I pulled out/in the usb plug while uploading sketch and it uploaded fine :lol:
Pukao Hats Cleaning Services Ltd.

User avatar
RogerClark
Posts: 6673
Joined: Mon Apr 27, 2015 10:36 am
Location: Melbourne, Australia
Contact:

Re: Guide for under- and over-clocking the blue-pill needed

Post by RogerClark » Mon Jan 09, 2017 8:48 pm

Pito wrote:
The problem with No USB, is that there is No Reset to upload.
Yes, that I noticed too - I wanted to shot an utube video on the issue, but then I pulled out/in the usb plug while uploading sketch and it uploaded fine :lol:
True...

There is a lot to be said for having a separate USB device to handle uploads (and serial USB), rather than reply on the main MCU.
(especially for novice users and school environments etc etc)

Post Reply

Who is online

Users browsing this forum: No registered users and 3 guests