- Sat Aug 30, 2014 2:35 pm
#174298
I have three similar devices (USB side of it) which work just fine. These were working out of the box for Fedora 19, and these FTDI chips are very very common. There is a second side though, as you may need other software for whatever connects through the FTDI USB chip. A UART though is something I'd expect to also just work...two of my three devices connect to this or similar UART (the third is a JTAG debugger).
Mostly it simply means you didn't run the right application to actually know it worked. First thing to know is that the USB hotplug layer will send messages to logs when a USB device is attached/detached. If your distro has /var/log/messages, just run "tail -f /var/log/messages" while pluggin in and unplugging the device. If no messages log, try "dmesg | tail" to see the end of the dmesg output...then plug in the USB...and again run "dmesg | tail" to see if the hotplug layer noticed the device.
Assuming it did work, consider that USB serial UARTS have associated files created and removed upon plugin or removal. They will be in /dev and have names starting with ttyUSB, ending in a number, e.g., ttyUSB0 through ttyUSB3. The order of plugging in such devices means the numeric listing (0 through 3 for example) will also change...if /dev/ttyUSB2 worked before, it might change to ttyUSB1 if plugged in in a different order.
You need a program to talk to a serial UART. minicom is an example, I use gtkterm a lot. Your program will not realize there is a device if the serial end has not been connected. It is easier to give an example...I have several embedded devices I work with, all of which use a serial console through a serial port...and to these I have cables with USB on one end, and a serial UART on the other...the serial communication programs will fail to see the device if I have not first powered on the other end at least once.
FYI, support for various drivers like this are pretty much available out of the box for every popular linux distro. On the other hand, they are usually in the form of a loadable module...this means you can add and remove drivers without rebooting. You don't need a new distribution to get your driver in most cases, you just need your kernel configured for the driver which just might already exist but not be loaded.
An alternate way to see what your system sees on USB is "lsusb". Try this prior to plugging in your device, and again after.
Additional note: UARTS have speed settings and your serial console program like minicom or gtkterm have to be set to the same values to work. Most common is 115200 for speed, 8 bits, no parity, and 1 stop bit (8N1).
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