[SOLVED] Minicom communications to usb device

prl242 · 06-24-2020, 11:43 AM

Hi,

Has anyone had an issue where minicom is set to communicate with a usb device, command is sent. In order to see the response we need to close minicom and reopen it. The response is there.

We are using XUbuntu 12.04. The usb device is custom hardware (purchased) that uses ascii commands.

Thanks
Paul

TB0ne · 06-24-2020, 01:36 PM

Quote:

Originally Posted by prl242

Hi,
Has anyone had an issue where minicom is set to communicate with a usb device, command is sent. In order to see the response we need to close minicom and reopen it. The response is there.

We are using XUbuntu 12.04. The usb device is custom hardware (purchased) that uses ascii commands.

Well, since you don't say anything about the hardware or give us any specs, there's not a lot we can tell you. Serial communications is typically a dark art, so the first thing I'd check would be the baud/parity, followed by the echo (? Can't remember what it's called) settings in minicom. The manual on the purchased device should have specs on how to talk to it, and how to configure your client.

prl242 · 06-24-2020, 01:40 PM

Thanks. We have confirmed the port settings. Using wireshark to sniff the packets it looks like the response from the device is in two packets. And the first packet does not include an end of line character.

TB0ne · 06-24-2020, 02:35 PM

Quote:

Originally Posted by prl242

Thanks. We have confirmed the port settings. Using wireshark to sniff the packets it looks like the response from the device is in two packets. And the first packet does not include an end of line character.

Ok, great...we still don't know anything about the device, how you're connecting to it, what settings you're using, etc. Not sure what you think we can tell you without knowing ANYTHING other than you're using minicom to USB.

michaelk · 06-24-2020, 03:39 PM

I agree with TBOne that you have not provided enough information. Just because there isn't an EOL character should not prevent minicom from displaying incoming data although we do not know how its configured.

As stated hopefully the manual that came with the device has some information on its protocol. If it is online can you provide the URL?

I have used minicom with many many serial devices, real and virtual i.e USB where its communication is ASCII text without problems. Its just understanding how the protocol works.

TB0ne · 06-24-2020, 04:04 PM

To add to what's here already, the setting I was trying to think of earlier is "local echo". Posting the output of

Code:

stty -f /dev/whatever/usb/device/name -a

..would help. If istrip is set, it could cause problems.

prl242 · 06-24-2020, 04:37 PM

Hi all,

Thanks for the responses. The device we have is being integrated with a single board computer and I can not give many details of the device itself.

Our issue now appears not to be with the software configuration. It seems that improper electrical grounding is corrupting the usb communications. Not enough to completely fail though

Cheers
Paul