Forums » Software Development »
Additional serial port on the MityDSP Profibus dev-kit
Added by Mattias Ekstrom about 13 years ago
Hi, I'm wondering what the best way to get an additional serial port is? Is there support for usb-to-serial adapters?
I'm developing something that will need to have both serial, profibus and ethernet support for data transfer and with the standard serial port dedicated to terminal use I don't know what my best options are.
Best regards, Mattias
Hi Mattias,
I think that your best (or easiest) bet would be to use a usb-to-serial adapter on the Host (USB1) port. If you need more than one, you should be able to use a (powered) hub and attach multiple units. We have used Keyspan's USB adaptors successfully with this hardware and a properly configured kernel.
Other options:
- If you are using an FPGA based module, you could insert a UART core and pin out the UART to the expansion connectors, but that would require cobbing up a level translator circuit and DB-9 plug.
- If you aren't using an FPGA based module, I believe that it may be possible to use a PRU and create another serial port using OMAP-L138 GPIO pins, but we've not tried that here. You might check with TI about how to do that. You'll still need external level translators for this approach as well.
-Mike
Thanks for the speedy reply!
One extra port should suffice. I'll order one of the keyspan adapters right away.
I'm using the MityDSP-L138 SoM. Can you point me in the right direction for properly configuring the kernel?
I guess it's mostly loading the right modules? I'm using a serial-to-usb adapter with ubuntu VM you provided, but as it
auto-configured everything I've not gotten an oppurtunity to set it up myself yet.
It's running the default kernel at the moment.
Best regard, Mattias
Hmm, I don't really need a physical port. Is there any com over ethernet software availible for these systems?
/ Mattias
The default kernel and root filesystem may "just work". If you plug in the device you should see some messages about it and the device should appear as /dev/ttyUSB0. If that doesn't happen, then you'll need to run make menuconfig and add:
Drivers->USB Support->USB Serial Converter support->XXXX
Where XXXX is the model of the device you are using. We normally build this stuff directly in (not as a module) for embedded kernels, but that is are your discretion.
Load up your new kernel and I think you should be off and running.
-Mike
(re: comm over ethernet)
Is ssh acceptable? "ssh root@mitydspaddr"
-Mike
No, I don't think ssh would work. It has to be something I could open and interact with just like a com port from my code, I'm not sure you can do that with ssh? Either way the recieving end is a windows box and it seems unlikely there would be any software for it on windows. But on the other hand I'm rather new to this so what do I know?! 
I'll just go with the serial-to-usb adapter, it seems like the obvious solution and they're pretty cheap anyway.
Thanks for all the help!
Just thought I'd add a note in case some one else stumbles upon this thread:
Ended up using a Prolific usb-to-serial device that was laying around the office.
I had to build a new kernel with support for usb-to-serial devices and this device
in particular, everything worked nicely as expected and all I had to do was to
reconfigure the kernel in the VM that comes with the board. And load it onto the
board of course.
/ Mattias
Go to top
