Smart Machine Smart Decision
SIM800C_Hardware_Design_V1.02
36
2015-4-27
4.11.
Operating Status Indication
The pin42 is for operating status indication of the module. The pin output is high when module is powered on,
and output is low when module is powered off.
Table 23: Pin definition of the STATUS
Pin name
Pin number
Description
STATUS
42
Operating status indication
Note: For timing about STATUS, please reference to the chapter “4.2 power on/down scenarios”
4.11.1.
STATUS Multiplexing Function
Table 24: STATUS multiplexing function
Pin name
Pin number
Mode 0(default)
Mode 1
STATUS
42
STATUS
GPIO
Note: Multiplexing function need different software supply.
4.12.
RF Synchronization Signal
The synchronization signal is used to indicate incoming GSM burst.
Table 25: Definition of the RF_SYNC pin
The timing of the synchronization signal is shown below.
T ransm it burst
R F _S Y N C
577us
220us
Figure 35: RF_SYNC signal during transmit burst
4.12.1.
RF_SYNC Multiplexing Function
RF_SYNC can also be used as GPIO to indicate the RF Jamming. The RF_SYNC function and RF Jamming
Detection function can be switched by AT+SJDR command.
Table 26: RF_SYNC Multiplexing function
Pin name
Pin number
Description
RF_SYNC
29
Transmit synchronization signal
