#384 FTDI plugin has unobvious configuration requirement

[Ximin Luo]

As a noob, I initially configured the FTDI plugin as follows:

driver = ftdi
device = /dev/ttyUSB0

mode2 then gave me an error "Cannot initiate device". There was no error in logs even when I gave -D trace, or loglevel = 10 in lirc_options.conf. Nowhere else online could tell me what the problem was.

Finally after looking at the source code, I realised that device = was not supposed to be a device file, but a bunch of config options. I tried deleting the device = line, but that also gave errors. Finally, I tried:

driver = ftdi
device = 

That is, an explicitly empty device = line. This worked for IR receiving, but it wasted about an hour of my time. Probably others will run into the same problem.

(For IR transmission there is another bug specific to my device, which I filed as #383).

Tested on version 0.10.1-6.3ubuntu1.