More explicit example in the main README?

[rubyFeedback]

Hey there Lars,

Right now the samep code shows this:

usb = LIBUSB::Context.new
device = usb.devices(idVendor: 0x04b4, idProduct: 0x8613).first

I don't know how to obtain these 0x04b4 entries.

When I do this I get "nil" value.

Is there some way to obtain a list of all ids currently plugged in? I have an USB stick plugged in.

Not sure how to get the vendor id.

Could the example show this for when you insert a new USB device, how to find out the ID and
then use that to query content, or auto-mount at a later time? Right now this is an obstacle as
I don't know how to get the vendor id as such. Perhaps the example can be extended to
find out the IDs somehow. Thanks.

[larskanis]

To retrieve all connected devices, it's best to use irb -rlibusb and call devices without arguments like so:

LIBUSB::Context.new.devices

It shows something like:

=> 
[#<LIBUSB::Device 4/1 1d6b:0003 ? ? ? (Hub (00,03))>,                                   
 #<LIBUSB::Device 3/1 1d6b:0002 ? ? ? (Hi-speed Hub with single TT)>,                   
 #<LIBUSB::Device 2/1 1d6b:0003 ? ? ? (Hub (00,03))>,                                   
 #<LIBUSB::Device 1/3 0489:e0a2 ? ? ? (Bluetooth)>,                                     
 #<LIBUSB::Device 1/2 0bda:58f4 ? ? ? (Interface Association Descriptor)>,              
 #<LIBUSB::Device 1/4 27c6:5385 ? ? ? (Interface Association Descriptor)>,              
 #<LIBUSB::Device 1/1 1d6b:0002 ? ? ? (Hi-speed Hub with single TT)>]                   

The left number is the vendor ID and the right number is the product ID.
Alternatively you can use lsusb on the command line.