UART/Serial Connection

yschandra

I am looking for UART pins for serial connection on the board to get into u-boot? Where can I find this info?

loverpi

USB keyboard/mice works. Just press escape twice on startup. For UART, it's pin 3,5,6 for TX,RX,GND respectively.

yschandra

loverpi said:

USB keyboard/mice works. Just press escape twice on startup. For UART, it's pin 3,5,6 for TX,RX,GND respectively.

Thanks, you mean pin 3,5,6 on 40 pin header?

RayKnight

yschandra said:

loverpi said:

USB keyboard/mice works. Just press escape twice on startup. For UART, it's pin 3,5,6 for TX,RX,GND respectively.

Thanks, you mean pin 3,5,6 on 40 pin header?

Yes the UART is available via pin 3, 5 and 6 on the 40 pin header.  I have confirmed this. 

janek

Hi,

I successfully boot debian image and have uart console working, but after second boot i always have this message on console:

Cannot open access to console, the root account is locked.

I can't get into system anymore, only flashing whole usb pendrive with fresh image helps. There are lots of topics about this on the web but here they use efi and systemd and I can't find solution with this setup. Does anybody figure it out?

janek

I found this thread https://www.reddit.com/r/LaFrite/comments/c89wym/frustrating_so_far/ where there is solution for that, but when I checked image on my pendrive /etc/fstab is already correct:(

janek

Ok, mystery solved. There are two subvolumes on this debian image. One has correct values and the second doesn't.

yschandra

RayKnight said:

yschandra said:

loverpi said:

USB keyboard/mice works. Just press escape twice on startup. For UART, it's pin 3,5,6 for TX,RX,GND respectively.

Thanks, you mean pin 3,5,6 on 40 pin header?

Yes the UART is available via pin 3, 5 and 6 on the 40 pin header.  I have confirmed this. 

Yes this is correct information, I could get in to uboot environment.