Board Addressing

Each Opera Cake has a numeric address set by optional jumpers installed on header P1. The default address (without jumpers) is 0. The --list or -l option can be used to list the address(es) of one or more Opera Cakes installed on a HackRF One:

hackrf_operacake -l

The address may be set to any number from 0 to 7 by installing jumpers across the A0, A1, and/or A2 pins of header P1.

Address	A2 Jumper	A1 Jumper	A0 Jumper
0	No	No	No
1	No	No	Yes
2	No	Yes	No
3	No	Yes	Yes
4	Yes	No	No
5	Yes	No	Yes
6	Yes	Yes	No
7	Yes	Yes	Yes

When configuring an Opera Cake, the address may be specified with the --address or -o option:

hackrf_operacake -o 1 -a A1 -b B2

If the address is unspecified, 0 is assumed. It is only necessary to specify the address if the address has been changed with the addition of jumpers, typically required only if multiple Opera Cakes are stacked onto a single HackRF One.