125-10 Serial Console

[darrynjordan]

Hi there,

I'm having trouble getting a serial console up and running with the 125-10. I've soldered the required pins and have connected a 3.3V serial to USB adapter. I've confirmed that the adapter is functioning correctly by connecting to another device. I'm using the stock standard RP SD image. I've tried using picocom, minicom and screen with numerous different baud rates, but all of them return the following garbage on boot (which I believe may indicate an incorrect rate?)

Code: Select all

picocom /dev/ttyUSB0 -b 115200
picocom v3.1

port is        : /dev/ttyUSB0
flowcontrol    : none
baudrate is    : 115200
parity is      : none
databits are   : 8
stopbits are   : 1
escape is      : C-a
local echo is  : no
noinit is      : no
noreset is     : no
hangup is      : no
nolock is      : no
send_cmd is    : sz -vv
receive_cmd is : rz -vv -E
imap is        : 
omap is        : 
emap is        : crcrlf,delbs,
logfile is     : none
initstring     : none
exit_after is  : not set
exit is        : no

Type [C-a] [C-h] to see available commands
Terminal ready
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Any help/suggestions would be greatly appreciated.

[darrynjordan]

Small update: If I ssh into the RP and cat /dev/ttyPS0, then run picocom /dev/ttyUSB0 -b 115200 in a second terminal, every second keystroke appears on ttyPS0. Output on picocom is still garbage.

[darrynjordan]

Any help/suggestions would be greatly appreciated.

[darrynjordan]

Bump?

[juretrn]

Which cable are you using? Did you connect the pins correctly? Did you connect the ground pin?
Sounds like you've got a bad connection or your ground is not that good.

This command
picocom /dev/ttyUSB0 -b 115200

works fine when connecting to my 125-14.

[redpitaya]

Sorry for the late reply. Please also double-check the solder joints as it might cause issues.

[darrynjordan]

Thanks for the response. I have double checked the solder joints and conducted a few more tests which I detail below.

- If I use "picocom -b 115200 /dev/ttyUSB0" on my host PC, and "picocom -b 115200 /dev/ttyPS1" on the RP 125-10, while connecting to UART1 on E2 then everything works as expected i.e., input on the host registers on PS1 and vice versa. This proves that my adapter is not to blame.

- However, if I connect UART0 to UART1 on the RP itself and open two instances of picocom for PS0 and PS1 respectively i.e., "picocom -b 115200 /dev/ttyPS0" and "picocom -b 115200 /dev/ttyPS1", then input on PS0 appears on PS1 correctly, however, the input on PS0 does not get displayed in its own console. In this same configuration, input on PS1 does not appear on PS0 correctly. Several keystrokes on PS1 are required to get any output on PS0 at all. Note that this is similar, but not the same behavior when compared to using an UART to USB adapter and connecting to PS0 - when using an external adapter input on PS0 does not appear for the host.

At this point I am not sure what to do. I need access to console output. Please any assistance would be appreciated. Without access to serial console output I can not use the RP for my project.

[darrynjordan]

I got my hands on a different USB-TTL adapter and everything worked as expected. Thanks for the help.