Pin Description - SIM Tech SIMCom SIM800C Hardware Design

3.2. Pin Description

Table 5: Pin description
Pin name Pin number
Power supply
VBAT 34,35
VDD_EXT 40
8,13,19,21,27,30,
GND
31,33,36,37
Power on/down
PWRKEY 39
Audio interfaces
MICP 9
MICN 10
SPKP 11
SPKN 12
GPIO
NETLIGHT 41
STATUS 42
Serial port
UART1_DTR 6
UART1_RI 7
UART1_DCD 5
UART1_CTS 4
UART1_RTS 3
UART1_TXD 1
UART1_RXD 2
UART2_TXD 22
UART2_RXD 23
Debug interface
USB_VBUS 24
USB_DP 25
USB_DN 26
ADC
ADC 38
SIM card interface
SIM_VDD 18
SIM800C_Hardware_Design_V1.00
I/O Description
I Power supply
O 2.8V power output
Ground
PWRKEY should be pulled low at
I least 1 second and then released to
power on/down the module.
I Differential audio input
O Differential audio output
O Network status
O Power on status
I Data terminal ready
O Ring indicator
O Data carrier detect
O Request to send
I Clear to send
O Transmit data
I Receive data
O Transmit data
I Receive data
I
I/O Debug and download
I/O
10bit general analog to digital
I
converter
Voltage supply for SIM card.
O
Support 1.8V or 3V SIM card
14
Smart Machine Smart Decision
Comment
If these pins are unused,
keep open.
GND for VBAT recommend
to use 36,37pin
Internally pulled up
VBAT.
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.
All signals of SIM interface
should be protected against
2014-10-30
to