Pin Description - SimCom SIM900D Hardware Design

3.2

Pin Description

Table 4: Pin description
Pin name Pin number
Power supply
VBAT 38,39
VRTC 15
AGND 22
17,30,31,32,
GND 34,35,36,37,
48
Power on/down
PWRKEY 12
Audio interfaces
MIC1P 21
MIC1N 20
SPK1P 23
SPK1N 24
MIC2P 18
MIC2N 19
SPK2P 26
SPK2N 25
Status
STATUS 5
NETLIGHT 41
LCD interface
DISP _CLK 13
DISP_DATA 14
DISP _D/C 16
DISP _CS 46
GPIOs
GPO1 40
KBR0 10
Serial port
RXD 3
TXD 4
SIM900D_Hardware Design_V2.02
I/O Description
I Power supply
I/O Power supply for RTC
Analog GND
Ground
PWRKEY should be pulled low at least
I 1 second and then released to power
on/down the module.
I Differential audio input
O Differential audio output
I Differential audio input
O Differential audio output
O Power on status
O Network status
O
I/O
Display interface
O
O
GPIO
I/O
GPIO
I Receive data
O Transmit data
14
Smart Machine Smart Decision
Comment
It is recommended to
connect with a battery or
a capacitor (e.g. 4.7uF).
Pulled up internally.
If these pins are unused,
keep open.
If these pins are unused,
keep open.
If these pins are unused,
keep open.
If these pins are unused,
keep open.
This pin should be
pulled up to 3V
externally.
If these pins are unused,
2012-05-07