Specifications

M12 Hardware Design
M12_HD_V3.3 - 45 -
9
8
7
6
5
4
3
2
1
15
14
8
9
11
12
5
7
6
10
4
26
2
27
13
18
20
21
16
17
19
22
23
24
3
1
25
28
GND
TO PC serial port
SP3238
3V
GND
GND
T5OUT
/SHUTDOWN
V+
GND
V-
VCC
T4OUT
T2OUT
T3OUT
T1OUT
R3IN
R2IN
R1IN
/STATUS
3V
ONLINE
R1OUT
R2OUT
R3OUT
/R1OUT
GND
T5IN
T4IN
T3IN
T2IN
T1IN
C2+
C2-
C1-
C1+
MODULE
RXD
DTR
RTS
RI
CTS
TXD
DCD
Figure 26: RS232 level match circuit
3.9. Audio interfaces
The module provides two analogy input channels and two analogy output channels.
Table 10: Pin definition of Audio interface
Interface
Name
Pin
Function
(AIN1/AOUT1)
MIC1P
23
Microphone1 input +
MIC1N
24
Microphone1 input -
SPK1P
22
Audio1 output+
SPK1N
21
Audio1 output-
(AIN2/AOUT2)
MIC2P
25
Microphone2 input +
MIC2N
26
Microphone2 input -
SPK2P
20
Audio2 output+
AGND
19
It is suggested AGND is used in audio
circuit. Do not connect it to digital
ground in host PCB which could produce
TDD noise.
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