ST-Link to update

[Pulsapharer]

I have a 3d printer with a Btt skr pro v1.2 motherboard. The Sd card slot is non functional so looking to update the firmware directly.

can I use a st-link v2 to upload the firmware from the pc to the motherboard?

the motherboard has a stm32 controller chip, but I don’t believe it has a bootloader!

[AScha.3]

It has a booloader - but can you get it working ? Need to set boot0 hi ... do you have curcuit diagram?

+ Which cpu is it ?

[Pulsapharer]

https://github.com/bigtreetech/BIGTREETECH-SKR-PRO-V1.1/blob/master/SKR-PRO-V1.2/Schematic/SKR-PRO-V1.2.PDF

this is a diagram 

[Pulsapharer]

It states it has a 

ARM 32-bit Cortex-M4 CPU

[AScha.3]

Ok, so its : F407 , boot0 you can set at J1 , 1-2 .

And to connect : maybe try USB port, to connect with STM32CubeProgrammer (download, if you dont have it.), 

in DFU / USB mode.

+

But how to use this board, if sd-card not working ? I thought, gcode is loaded by sd-card ?

[Pulsapharer]

So, just to clarify jumper 1 short across 1 and 2. When I plug in the st link into the pc do I connect the cables as per diagram on the outer case? Rst to rst, swdio to swdio, etc? Also, I send the geode files via Ethernet using an Arduino uno board with Octaprint

[AScha.3]

No - if you have a (working) st-link, you can connect to J44 , swd port.

no need to set boot jumper !

You only need connect : swd, swc, gnd .

set CubeProgrammer then to : st-link, connect normal,  software reset.

You have to see : st-link serial....then try : connect.

get you connection ? Then can upload/flash new software.

[Pulsapharer]

Do I need to have the skr motherboard powered ? 

[AScha.3]

No power, no fun. (But just the cpu, not the motors etc.)

Maybe (!) , just giving 3v3 from st-link is enough - try it. (to vcc 3.3v ) (dont connect 5V here ! Kill cpu ! )

The pinout here...i cannot understand, something wrong: pin1: seems vcc 3v3, pin2 : swd , 3: gnd, 4 swc, 5 trst.

But left writing is totally different... so whats real ? Best: check -un-powered- with a DMM, where is gnd and 3v3.

To see: what writing is real.