Hardware revision 0 does NOT support the PDI or aWire interface, and have serial numbers starting with A0... as shown here.

Hardware revision 1 supports both PDI and aWire. Serial numbers start with A09-0041 or B0... as shown here.

Revision 1 also has a green LED inside the encapsulation, which light up when a USB connection is made.

Revision 1 units are also fully RoHS compliant.