STM32F-407G-Disc1 booting only right after firmware flashing.

[Ddela.1]

Hi

I am working on an audio application (see http://ixox.fr/forum/index.php?topic=63425.45) and I am experiencing an issue:

• when I just flash the app, whilst still plugged in on my desktop, the app boots and works fine.
• When I power the board without a PC connection, it keeps blinking slowly red on LD1and nothing happens.

My board is a STM32F407G-Disc1 , serial being : MB995-D-01 / 218509479.

I have found many people describing similar issues: explanation the ST-LINK firmware pulls the NRST Low etc...

None of their proposed workarounds seems to work ...

I already

• tried removing SB11 blob -- no good -- set it back.
• pulling RST to 3.3V through a resistor -- not convincing.
• upgraded the ST-Link firmware to the most recent version V2J36M26, tries several available versions (2.32; 2.33). Some people mention the 2.24 or 2.25 being OK but they seem not available.

I am lost.

I would need it to work soon as is is intended as a gift for my son who studies electronic music before he returns to his college :(

Has anyone a method that works?

In absence of any working way, the interest of that board is dramatically reduced.

Regards

Dominique

[TDK]

Without a PC, LD1 will simply indicate the USB is still enumerating. No surprise there.

As far as the chip "doing nothing," more likely the chip is stuck in a loop somewhere. Could be the HSE takes too long to power up, or some other component isn't ready when the chip tries to access it. If that's the case, you could try putting a delay before clocks are initialized.

Does it still "do nothing" if you reset it while not connected to a PC? Or just on power-up?

You can attach to the chip after it's already powered to figure out where the CPU is. Change your debug configuration to not download or reset when it starts.

[Ozone]

Or, you could add telemetry (debug output), to see what the board does in this case.

Do you use IAP (i.e. writing to Flash from within you application) ?

[KnarfB]

How do you power the board without a PC connection? USB?

[Ddela.1]

Hi

Thanks for your answers. I get it about blinking LD1, makes sense.

The application can write flash to enable update but, in the present case, I have been so far flashing from a Debian box, using st-link tools, the most recent version found in git.

I power through USB, using a stable powerful 5V/3.0 Amps supply.

I will try and find a way to look at debug.

[EDIT] The system has a bootloader app to manage updates and config changes and a main app.

Apparently it works only when flashing the main app -- I assume st-flash then starts from its start address.

Now debugging, I am under the impression the boot loader is trapped in a loop. I dig deeper from here.

Regards