SIM Tech SIMCom SIM800C User Manual

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SIM800C_Hardware_Design_V1.00 25 2014-10-30
4.5. Serial Port and USB Interface
SIM800C default provides one unbalanced asynchronous serial ports. The module is designed as a DCE (Data
Communication Equipment). The following figure shows the connection between module and client (DTE).
Table 8: Serial port and USB pin definition
Note: Hardware flow control is disable by default. AT command “AT+IFC=2, 2”can enable hardware flow
control. AT command “AT+IFC=0,0”can disable hardware flow control. For more details please refer to
document [1].
Table 9: Serial port characteristics
Symbol
Min
Max
Unit
V
IL
-0.3
0.7
V
V
IH
2.1
3.1
V
V
OL
-
0.4
V
V
OH
2.4
-
V
SIM800C module can support dual serial port function, that need execute AT command "AT+CMNRP=1"first.
Dual serial port including one full modem serial port and one three-wire serial port, pin definition is different with
standard definition of the Figure 2: Pin assignment (Top view) and Table 5: Pin description. For more details
please refer to Document [2].
4.5.1 Function of Serial Port
Serial port:
 Full mode device.
 Contains data lines UART1_TXD and UART1_RXD, hardware flow control lines UART1_RTS and
UART1_CTS, status lines UART1_DTR, UART1_DCD and UART1_RI.
Pin name
Pin number
Function
Serial port
UART1_DTR
6
Data terminal ready
UART1_RI
7
Ring indicator
UART1_DCD
5
Data carrier detect
UART1_CTS
4
Request to send
UART1_RTS
3
Clear to send
UART1_TXD
1
Transmit data
UART1_RXD
2
Receive data
UART2_TXD
22
Transmit data
UART2_RXD
23
Receive data
Debug port
USB_VBUS
24
USB power supply
USB_DP
25
USB_DN
26

SIM Tech SIMCom SIM800C Specifications

General

Brand	SIM Tech
Model	SIMCom SIM800C
Category	Control Unit
Language	English