Audio Interface
1-4
Audio EI3 Extender Board Manual
Audio Interface
The SigmaDSP ADAU1761 (
U2
) connects to the SPORT interface of the
EI3 connector (
J1
). All control and setup communication uses the TWI
interface. The TWI address is set to
0111 000X
(where
X
is the read or
write bit) by resistors R9 and R10. The last two address bits can be
adjusted through populating R7 and/or R8, in conjunction with depopu-
lating R9 and/or R10.
There are two input connectors and two output connectors.
J2
is the ste-
reo headphone output.
J3
is line out and is a single-ended stereo output.
J5
is the auxiliary input.
J4
connects a single-ended stereo line in to the
codec. A standard 3.5 mm male-to-male cable connects to any of these
four connectors.
The board also has two omnidirectional MEMS microphones, which are
Analog Devices part number ADMP421
ICs (U3 and U4). The micro-
phones connect gluelessly to the ADAU1761 processor.
Example programs demonstrating the audio interface capabilities are
included in the CrossCore Embedded Studio directory. Once installed,
the example programs can be found in the
<
install_path
>\Audio_EI3_
Extender_Board-Rel
X.X.X
\Audio_EI3
directory, where
X.X.X
denotes the
support package release number.
Connectors
The LED, connector, and jumper locations are shown in
Figure 1-1
.
The
J2–J5
connectors are 3.5 mm stereo jacks from CUI Inc. (part num-
ber SJ-3523-SMT). Use any 3.5 mm audio cable to connect to
J2–J5
.
The
P1
connector is a 0.65 mm power jack from CUI Inc. (part number
CP1-022PJTR-ND). Use this jack when the EZ-KIT Lite/EZ-Board can-
not provide adequate power. The 5V adaptor is then connected to
P1
and
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