AnsweredAssumed Answered

Nucleo board USB and SDIO signal integrity

Question asked by Mikk Leini on Aug 25, 2015
Latest reply on Oct 8, 2015 by Mikk Leini
I am thinking of building several "shields" with GSM, GPS, LCD, MicroUSB and MicroSD connectors to stack up on the STM32F401 Nucleo board (by the dual row connectors, not Arduino) but i'm worried about the signal integrity of the USB and SDIO traces. It's a pity that ST didn't put user USB (not even connector footprint) on the Nucleo boards. So now i'm not sure at all if the USB (device) will work flawlessly if the connections go through the 0.1" pinheaders. The headers go up and down so whether i connect my extension board bottom or top there will always be a stub on D+/D- unless i cut the other header. But nothing can be done about the non-matched impedance and other issues. I have similar worries about SDIO also.

Does anybody have experience with Nucleo board and USB/SDIO ? Or can somebody with better electronic knowledge comment this? Most secure option what i could think of is that i put USB and MicroSD on the expansion board that goes right on top of Nucleo board and i cut all the USB and SDIO pins which go further up. Would that be enough to avoid troubles?

I ordered the Chinese Waveshare XNUCLEO board also which has the user USB on main board, but unfortunately they haven't connected OTG_FS_VBUS (PA9) pin to USB VBUS :((