www.st.com st-link: is it bidectional

Post Reply
Posts: 1681
Joined: Wed Jul 08, 2015 2:09 pm
Location: St Annes, Lancs,UK

www.st.com st-link: is it bidectional

Post by zmemw16 » Fri Jul 24, 2015 5:49 pm

after encountering a read problem with an externall type st-link compatible, its been pointed out that they aren't bi-directional.
consequently the read verify and usb re-enumeration were problematicly.
http://www.stm32duino.com/viewtopic.php ... 4210#p4210

i happen to have a 'real' white egg st st-link, do they actually behave correctly?
i'll start rooting for it in the meantime....


User avatar
Posts: 7683
Joined: Mon Apr 27, 2015 10:36 am
Location: Melbourne, Australia

Re: www.st.com st-link: is it bidectional

Post by RogerClark » Fri Jul 24, 2015 9:36 pm

There is no reason for the STLink board to re-enumerate after upload.

The only upload method that should re-enumerate is the bootloader upload.
I really should write a blog post about why this is necessary, and i'm sure I've posted about why...
But basically Windows wont accept the DFU upload device and the Serial USB device on the same hardware at the same time but using different driver dll's in Windows (both DFU and Serial USB use built in Windows drivers)

I'm also not sure what you mean by bi-detectional. Do you mean bi-Directional ?

You can upload via stlink, and you can manually download from stlink, and you can manually debug via stlink (search the forum, there are instructions and scripts for how to do this on Linux)
However what STlink does not provide is Serial input or output.
If you want your debugger / programmer hardware to do that, you will need to reflash the internal firmware with something link Black Magic Probe (this is also well documented if yiu search on the forum). However most stlink adaptors can only be reprogrammed with another stlink adaptor, unless you are able to solder to the chip, as only the SWD pins are broken out.
And to use BMP youd also need to solder to PA9 and PA10 on the stlink and connect them to PA10 and PA9 on your target board.

Overall, i think you really need to post significantly more information about your whole setup, for us to give you a much better response.

Posts: 1681
Joined: Wed Jul 08, 2015 2:09 pm
Location: St Annes, Lancs,UK

Re: www.st.com st-link: is it bidirectional

Post by zmemw16 » Fri Jul 24, 2015 11:49 pm

minor title change

lenovo i7 laptop debian 8 up to date very soon.
i5 + amd laptops, netbook and i7 desktop

arduino 1.6.5 from the linux 32bit tgz arduino.cc
arduino-stm32 as of 2.5 days

st link as in original, with quite a selection of the cheap 'clones'
mainly a fair few stm32f103c8t6 baite, blue pills, maybe a few red & various devel boards
certainly a few rbt variants, couple of vet/zet's and a cz ministm32f103zx-ek as well

arduino avr - oh most definitely adequate

enough smd stuff for most anything, oven etc, cnc x2 & 3d printer x2 and miniature laser engraver

i went ott with the ppi refund! might as well get sorted for dark winter evenings, days as well

i retired 31/3/2011; 40yrs hardware/software engineer. last 16yrs lucky enough 2b using a linux box, @home since '94/95 0.98/0.99???
linux and new hardware, relax and wait; it'll work somewhen:-)

relaxation - ICE Trice QNT recumbent trike and 2500mls blackpool to blackpool following coastline <5mls via lands end, dover and hull.
develops a totally different patience.
next yr other half, same except its 3000+ mls via the islands and john o'groats

maybe that belongs in welcome:-)

Post Reply