Schematics

MCU
KEY
、
、、
、
LED
C3 NC
AGND
BT_OSCO
BT_OSCI
+3.3V
VBAT
GND
C1 105
C2 NC/10V
C8
2.7P
BT_ANT
L1
NC
L2
NC
BT_RF
BT_ANT
DC5V
BT_OSCO BT_OSCI
Y1 24M
J1
Earphone
DACL
DACR
DACL
DACR
MIC
P/P/POWER
LED_B/R
C4 105
BT_AVDD
KEY
+
M1
MIC
MIC
C7
NC
BAT
3.4V~4.2V
VBAT
+5V
1
DM
2
DP
3
ID
4
6
GND
6
6
6 6
J2
USB(MICRO)
DACL
DACR
DACL
DC5V
T4 DM
T3 DP
T2 GND
T1 VBAT
VBAT
GND
USBDP
USBDM
USBDP
USBDM
VDDIO
1
VBAT
2
PB1/ADC5
6
DACVSS
15
ADC1/MIC/PA1
16
ADC14/USBDM
11
MIC_BIAS/PA2/PA3/USBDP
12
BT_OSCI
9
BT_OSCO
10
BT_RF
7
VSSIO
8
PB3/ADC6
5
DACL
14
LDO_IN/PB5
3
BT_AVDD
4
DACR
13
U1
T5 3.3V
+3.3V
D1
BLUE
D2
RED
S2
PREV/V+
S3
NEXT/V-
S1
P/P/POWER/TALK
P/P/POWER
LED_B/R
KEY
KEY
+3.3V
S5
PREV/V+
S6
NEXT/V-
S4
P/P/POWER/TALK
P/P/POWER
R7
51K
R3
27K
R2
NC
+3.3V
0V
2.41V
2.76V
P/P/POWER
S7
P/P/POWER/TALK
P/P/POWER
R4
100K
R1
NC/10K
L/R_SEL
AC6969