USB to COM Port connections

[Rick Stevens]

On 05/26/2015 12:45 PM, Mickey wrote:
>
>
> On 05/26/2015 01:19 PM, Bob Goodwin - Zuni, Virginia, USA wrote:
>>
>>
>> On 26/05/15 13:07, Gordon Messmer wrote:
>>> On 05/26/2015 08:44 AM, Mickey wrote:
>>>> Ed, I look through Thunderbirds Preferences and I could not find those
>>>> settings, where are they located ?
>>>
>>> Not under preferences, but under account settings.
>>>
>>> Edit -> Account Settings -> <your account> -> Composition &
>>> Addressing -> Compose messages in HTML format.
>>>
>> Or:
>>
>> Preferences > Composition > General >  Send options
>>
> Finally got my Drone Flight Controller Connections in WIndows 7 working,
> the tech guy at the company in San Diego used the App Teamviewer to
> connect to my Laptop and get the correct Com Ports working.
>
> BUT!!!!, I would prefer  to be working with Fedora 21 , if I could only
> get the USB/COM port working to connect MissionPlanner to my Drone.

Most USB<-->serial dongles show up as "/dev/ttyUSBx" where the "x" is a
decimal digit starting at 0, so yours will most likely be
"/dev/ttyUSB0". You can do an "ls /dev/tty*" before you plug it in, and
again after you plug it in and you should see the device show up.

If your dongle uses a special driver, then the device name will most
likely be different. As someone said, you could (as the root user) run
"dmesg" immediately after plugging in the device and somewhere towards
the end of the data that's displayed should be an indication as to the
device's name (assuming the kernel actually recognizes the device).

Example of my USB<-->serial dongle:

[1120743.665209] usb 1-1: new full-speed USB device number 66 using xhci_hcd
[1120743.834890] usb 1-1: New USB device found, idVendor=0403, 
idProduct=6001
[1120743.834899] usb 1-1: New USB device strings: Mfr=1, Product=2, 
SerialNumber=3
[1120743.834903] usb 1-1: Product:     USB Serial Converter
[1120743.834907] usb 1-1: Manufacturer: FTDI
[1120743.834911] usb 1-1: SerialNumber: FTCEGM4N
[1120745.470813] usbcore: registered new interface driver ftdi_sio
[1120745.470825] usbserial: USB Serial support registered for FTDI USB 
Serial Device
[1120745.470891] ftdi_sio 1-1:1.0: FTDI USB Serial Device converter detected
[1120745.470921] usb 1-1: Detected FT232BM
[1120745.471617] usb 1-1: FTDI USB Serial Device converter now attached 
to ttyUSB0

Note the last line. So my device is /dev/ttyUSB0, and an "ls -l" of the
/dev directory shows it:

[root at prophead ~]# ls -l /dev/ttyU*
crw-rw----. 1 root dialout 188, 0 May 26 13:00 /dev/ttyUSB0

You can see that the ownership of the device is "root:dialout" and the
permissions are 660, so in order to use it, the application MUST run as
either the root user or be a member of the "dialout" group. If this is
a GUI program run from your desktop, then your user account must be a
member of the dialout group. You can do that via:

	sudo usermod -G dialout <your-user-name>

If the program requires a specific device name (and you can't use
"/dev/ttyUSB0"), then (as root) you can create a symlink to the device,
e.g.

	sudo ln -s /dev/ttyUSB0 /dev/whatever-name-you-need

then use "/dev/whatever-name-you-need" in the application.
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- Rick Stevens, Systems Engineer, AllDigital    ricks at alldigital.com -
- AIM/Skype: therps2        ICQ: 226437340           Yahoo: origrps2 -
-                                                                    -
-                   To err is human, to moo bovine.                  -
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