Lite board support

[bittware]

Hello,
I bought a lite MCU board which only features STM32F405RGT and a couple of buttons and LEDs.
But after I flashed in the latest MicroPython, the computer can not recognize it a removable disk like my genuine Mircopython board does.
I don't know what's going wrong. Could anyone give me some hints?
Thanks in advance!
P.S. The schematic is attached. The real crystal is 8MHz which is not consistent with what is shown in the schematic.

[dhylands]

What are you doing with BOOT0 and BOOT1 ?

On the pyboard, BOOT0 and BOOT1 are both pulled to ground, which makes it run normally.

Pulling BOOT0 high during reset is what puts it in DFU mode.

Does USB serial work and USB Mass storage doesn't ? or does neither work?

What does lsusb show?

There are some other pullups that you should have to ensure proper bootloader operation. I recommend that you review AN2606, in particular Chapter 11, which covers the 405:
http://www.st.com/web/en/resource/techn ... 167594.pdf

You'll see that the pyboard has pullups/pulldowns on all of the appropriate pins.

[bittware]

What are you doing with BOOT0 and BOOT1 ?

On the pyboard, BOOT0 and BOOT1 are both pulled to ground, which makes it run normally.

Pulling BOOT0 high during reset is what puts it in DFU mode.

Does USB serial work and USB Mass storage doesn't ? or does neither work?

What does lsusb show?

There are some other pullups that you should have to ensure proper bootloader operation. I recommend that you review AN2606, in particular Chapter 11, which covers the 405:
http://www.st.com/web/en/resource/techn ... 167594.pdf

You'll see that the pyboard has pullups/pulldowns on all of the appropriate pins.

Hello dhylands
Thank you for the tips.
In fact, this board could be set in DFU mode and Micropython binary was successfully flashed into it.
Boot1 is always fixed to ground. Boot0 was set to high during flashing process while set back to low afterwards.
The problem is it could not become USB mass storage hence I could not access to it through windows explorer.
USB serial doesn't work either. It seems PC is even not aware of anything being plugged into USB socket at all.
I ran it in windows7 and did not get chance to run tool like lsusb, but I will and let you know the result.

[dhylands]

The pyboard connects VBUS to PA9 to detect if the USB cable is plugged in or not.

I'm not seeing anything on your board to do that, so you may need to change:

https://github.com/micropython/micropyt ... .c#L73-L77
https://github.com/micropython/micropyt ... #L343-L347

Personally, I don't like the fact that HYDRABUS is even mentioned, and would prefer to see something about a VBUS detection feature.

It may make sense to expose the VBUS detection pin in pins.csv as well.

[bittware]

The pyboard connects VBUS to PA9 to detect if the USB cable is plugged in or not.

I'm not seeing anything on your board to do that, so you may need to change:

https://github.com/micropython/micropyt ... .c#L73-L77
https://github.com/micropython/micropyt ... #L343-L347

Personally, I don't like the fact that HYDRABUS is even mentioned, and would prefer to see something about a VBUS detection feature.

It may make sense to expose the VBUS detection pin in pins.csv as well.

dhylands, you hit the point! Problem solved. Thank you indeed.