Smart Machine Smart Decision
SIM800_Hardware Design_V1.09
26
2016-06-30
RESET
V
IL
<0.6V
VDD_EXT
STATUS
t>105ms
2.7s
t<400us
V
IH
>2.4V
Figure 15: Reset timing sequence
4.3.
Power Saving Mode
SIM800 has two power saving modes: Minimum function mode and sleep mode. The AT command
“AT+CSCLK=1”can be used to set SIM800 into sleep mode. The AT command “AT+CFUN=<fun>” can be used
to set SIM800 into minimum function. When SIM800 is in sleep mode and minimum function mode, the current
of module is the lowest.
4.3.1.
Function Mode
There are three function modes, which could be set by the AT command “AT+CFUN=<fun>”. The command
provides the choice of the function levels <fun>=0, 1, 4.
AT+CFUN=0: Minimum function.
AT+CFUN=1: Full function (default).
AT+CFUN=4: Flight mode (disable RF function).
Table 7: The current consumption of function modes (BS-PA-MFRMS=5)
<Fun>
Current consumption(mA) (CSCLK=1)
0
0.8
1
1.3
4
0.8
Minimum function mode minimizes the current consumption to the lowest level. If SIM800 is set to minimum
functionality by “AT+CFUN=0”, the RF function and SIM card function will be disabled. In this case, the
serial port is still accessible, but all AT commands correlative with RF function and SIM card function will not
be accessible.
For detailed information about the AT Command “AT+CFUN=<fun>”, please refer to
document [1]
.
4.3.2.
Sleep Mode (AT+CSCLK=1)
User can control SIM800 module to enter or exit the sleep mode (AT+CSCLK=1) by DTR signal. When DTR
is in high level and without interrupt (on air and hardware such as GPIO interrupt or data in serial port),
SIM800 will enter sleep mode automatically. In this mode, SIM800 can still receive paging or SMS from
