Schematics

5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
VBAT
DACVDD
MIC
VDDIO
VCC+5 V
KEY
KEY
MIC
AGND
VCC+5 V
AGND
VBAT
S2
POWER
B-
C7 0R
L-
C4 105
Y1
26MHz
C3 104
B+
R4
12K
R-
L+
IC1 AB5337B
8 9
10
5
7
6
1
2
3
4
16
15
14
13
12
11
VDDBT PW RKEY
BT_ANT
VDDIO
DGND
VBAT
VCMBUF
PE7/ADC9
AGND
VUSB
DACL
DACR
ADC10/MICL/PF2
ADC5/PB3
BT_OSCO
BT_OSCI
S3
FB/V-
L2
NC
1 2
S1
FF/V+
R2
47K
C5 104
C1 NC
R16.8K
C2 104
D1
BED_LED
D2 RED_LED
J2
USB2.0
6 7 8
9
5
4
3
2
1
6 7 8
9
MIC
MIC1
1
2
BAT1
3.7V
12
L1
NC
1 2
R+