Update README.md

README.md

@@ -39,3 +39,48 @@ Prerequisites
 * Look at lsusb output and make sure that your reader is present in 42-pn53x.rules
 * Install appropriate driver for your NFC reader (if required)
 * If your reader is plugged in unplug it and plug it again. If you run example below and get "Device or resource busy" error then you need to reboot your system before you can continue.
+
+Usage
+-----
+
+```ruby
+p "Library version: %s" % RubyNFC.version
+readers = RubyNFC::Reader.all
+p "Available readers: %s" % readers.to_s
+
+readers[0].poll(IsoDep::Tag, Mifare::Classic::Tag, Mifare::Ultralight::Tag) do |tag|
+ begin
+ p "Tag uid: %s" % tag.uid_hex
+
+ # This is how you can distinguish different type of tags
+ # and process them separately
+ # Some tags can have several interfaces i.e. PayPass/payWave cards
+ # with mifare chip on board so this case statement also defines priority
+ # of tag types
+ case tag
+ when Mifare::Classic::Tag
+ tag.select do
+ if auth(4, :key_a, "FFFFFFFFFFFF")
+ p "authenticated!"
+ processed!
+ end
+ end
+ when Mifare::Ultralight::Tag
+ tag.select do
+ p "Page 1: %s" % read(1).unpack('H*').pop
+ end
+ when IsoDep::Tag
+ tag.select do
+ # sending APDU command to tag using hex binary format
+ p tag << "\x00\xA4\x04\x00\x06\xF7\x52\x46\x54\x41\x01" 
+ # sending APDU command to tag using hex string format
+ # tag response will be delivered in a same format as an input
+ p tag << 'A00D010018B455CAF0F331AF703EFA2E2D744EC7E22AA64076CD19F6D0'
+ processed!
+ end
+ end
+ rescue Exception => e
+ p e
+ end
+end
+```