User's Manual

Smart Machine Smart Decision
SIM5320_Hardware Design_V1.01 2011-11-10
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Table 18: LED status
LED Status Module Status
Always On Searching Network/Call Connect
200ms ON, 200ms OFF Data Transmit
800ms ON, 800ms OFF Registered network
Off
Power off / Sleep
Flight mode control
GPIO4 controls SIM5320AD module to enter or exit the Flight mode. In Flight mode, SIM5320AD closes
RF function to prevent interference with other equipments or minimize current consumption. Bidirectional
ESD protection component is suggested to add on GPIO4.
Figure 26: Flight mode switch
Table 19: Control status
GPIO4 Status Module operation
Low Level Flight Mode: RF is closed.
High Level Normal Mode: RF is working.
Note
：
1. When the module is powered off, make sure all digital interfaces (UART, etc) connected with peripheral devices have
no voltage higher than 0.3V. If users’ design cannot meet above conditions, high level voltages maybe occur in GPIO pins
because current leakage from above digital interfaces may occur.