M50 Hardware Design
M50_HD_V2.0
- 49 -
The following circuit shows a reference design for the communication between module and PC.
Since the electrical level of module is 2.8V, so a RS-232 level shifter must be used.
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
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
To PC serial port
Figure 26: Level match design for RS-232
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