STM32F405 Can not connect to target

[Mhushki]

Hello All, I Hope you are well.

I am facing a problem that I spent A LOT of time on. I designed a custom board featuring the STM32F405RGT6 but i cannot connect to it at all.. I will attach the schematic and the board's pictures below. (The schematic is a PDF where I attached the sheet of the MCU's circuitry only there are other sheets for other parts of the board)

Things to mention:
1- I've assembled the board myself (But i checked the connectivity and voltages on the necessary nodes by a multimeter and i tested on the chip's pins not on the PCB pads and got the following:

-VDD on all VDD pins are 3.31V (measured directly on the pins)

-VDDA is also supplied by the same source with around 3.31V (measured directly on the pins)

-Vcap1 and Vcap2 are both 1.26V (measured on the the two Caps of 2u2 value)

-Reset Pin is 3.31V

)

2- I got suspicious about the SWD pinout that i did so i used an adapter and a Nucleo board's ST-Link to connect to my board where I measured the resistance between the SWD Pins and the Nucleo board and all are connected with reasonable resistance (Under 10 Ohms) (I got so desperate of the cause that I replaced the termination resistors of 49R9 with 0Ohms ones)

3- I got in both modes of Boot0 being Low and High. (Boot1 is floating would that cause the lack of connectivity?)

Am I missing something?!

Any kind of help would be much much appreciate. Thank you in Advance.

 

 

[Mhushki]

@Tesla DeLorean  I commented few days ago on another post and i was advised by you to post my issue separately..

any idea sir? Thanks in advance 🙏

[AScha.3]

Hi, 

boot1 floating ... why ??

So you can not use bootloader, boot0 has to be low .

[Mhushki]

Thank you for your reply, 

I've soldered a wire and i pulled boot1 low through a 10k resistor.. and then tried to pull it high .. but with the same result.. would this mean that my chip is dead? 

Would it be dead even if i see the reset pin voltage as expected and both vcaps1&2 showing proper voltage? What do you think is the issue here?

[AScha.3]

Seems everything ok (if boot0 lo ! ) , should work.

Maybe you puzzeled the swd pins ? (mirrored pinout .... i have workmate, that "loves" to do this. But always 100% sure, he did right. )

Try connection with CubeProgrammer ... best, to see, whats going on.

Show, what it tells or shows.

[Mhushki]

I did miss up the swd pins.. however i connected the wires one by one (out from the adapter) to the st-link section of a Nucleo board (I tested this to identify a bluepill board which it did successfully).. and i tested with a continuity test from every single pin to the swd header on the Nucleo board

then i tried with my custom board but it didn't work.. it's very frustrating 

[AScha.3]

>I did miss up the swd pins

🙂

>then i tried with my custom board but it didn't work.

So you still have a very basic / *** error there.

What shows CubeProgrammer with your board ? ( show screenshot.)

[Mhushki]

Regarding the CubeProgammer, I'm sorry but i can't seem to find a place to download this anymore! Any ways I attached screenshots from st-link utility, and from the CubeIDE, as well as the application note and connections i used to recruit my Nucleo board's st-link as a programmer (which i tested successfully for a BluePill board (an stm32F103)).

I tested again the voltages and got the following:

VDD on all 4 digital supply pins is 3.35V

VDDA is 3.35V

NRST is 3.35V

Vcap1 is 1.26V

Vcap2 is 1.26V

Boot0 is 0V

Boot1 is 0V

 

  

[AScha.3]

So, st-link utility is old and deprecated. Not useful - dont use it.

+

CubeProgammer you must get. Where are you ?  (Maybe VPN (from Germany or France) could help, if yor country is on some blacklist . 🙂  (not my business..))

+

Message in IDE  helps nothing - just it cannot "see" any target. (Always same message - if not working.)

+

You connected also VDD 3v3 to st-link ? It checking the voltage, if too low, it dont work.

[Mhushki]

Thank you, i didn't know there was some kind of a blacklist in the first place,, anyways I'll try to get the CubeProgrammer and get back if i had any useful updates. Thanks again for your time.