uart connection blocks A13 olimex

[anra]

Hi I have used the UARTs ttyS0 and ttyS1. Both seem to work correctly. I have tried to echange data between A13 and other device. I have used stty -F /dev/ttyS0 or stty -F /dev/ttyS1 to select the port. If I connect my device when A13 is working, the UARTS work perfectly.
On the other hand, I  have switched off A13. Then I have kept my device connected and working.Then I have switched on A13. Then I have selected the port using stty -F /dev/ttyS1. But surprise, the terminal and all the A13 stay blocked without open the port.
So if the connection is made after the A13 is working: no problem
If I kept the connection and my device working (without sending data): I cant open the port and A13 is blocked. I have to push the reset bottom to go ahead.
does anyone know a solution for the problem?

[LubOlimex]

Hello there,

This might be caused by three things:

1. The board is sending data that interrupts the initial boot sequence. More accurately, after the kernel boot when you see the message "Press any key to abort..." a character is recognized off the UART and the boot gets aborted.

2. (As I already mentioned in our previous message exchange but I list in here for completeness) The second thing is that you have to disable the UART you are using as a debug port. By default it is used only for debugging.

If you disable it however you would limit the ways you might communicate
with the board. And you would probably need to use SSH connection (via
network) with the board. To disable debug port you should edit inittab file
in /etc directory. It should be something like:

#nano /etc/inittab
Comment
#T0:2345:respawn:/sbin/getty -L ttyS0 115200 vt100
Save and run
#init q

Remember that you would need to debug via SSH, monitor or display now on.

3. If the UART board is powered from the UEXT connector it might draw too much current (a heavy initial load on the power line) preventing the board from normal boot.

Best regards,
Lub/OLIMEX

[just_stereo]

Hi there,
I know this is not the right place to post, but I don't know where else to ask. I bought USB-ISO in 19 december 2013 and recived with DHL in 23 december 2013 and it doesn't work anymore.

When is connected is even worst than without being connected (sometimes is making very ugly noise in speakers during many seconds when I turn off/on the light or any other switch in the house, and the only way to stop that noise is to turn OFF my DAC ). The noises sounds like firecrackers or like playing with a battery on one speaker, but louder.

Dosen't isolate anything from my pc, it just making worst. In first few days was ok, but after few days it started to work with malfunction.

What can I do
Please help me!
Thanks in advance.

P.S.: I don't want to talk about this problem in different hi-fi forums and make bad commercial, I really hope somebody will help me. My DAC is Arcam rDAC .

[olimex]

please use support@olimex.com and do not spam other people post!

[just_stereo]

sorry and thanks