SIM802 Hardware Design
interface signal can be used to lead system to be SLEEP mode (or Slow clocking mode).
3.6.1 Minimum functionality mode
Minimum functionality mode reduces the functionality of the module to a minimum and, thus,
minimizes the current consumption to the lowest level. This mode is set with the “AT+CFUN”
command which provides the choice of the functionality levels <fun>=0
，
1
，
4
z
0: minimum functionality;
z
1: full functionality (Default);
z
4: disable phone both transmit and receive RF circuits;
If SIM802 has been set to minimum functionality by “AT+CFUN=0”, then the RF function and
SIM card function will be closed. In this case, the serial port is still accessible, but all AT
commands need RF function or SIM card function will not be accessible.
If SIM802 has been set by “AT+CFUN=4”, then RF function will be closed. In this case, the
serial ports is still active, but all AT commands need RF function will not be accessible.
After SIM802 has been set by “AT+CFUN=0” or “AT+CFUN=4”, it can return to full
functionality by “AT+CFUN=1”.
For detailed information about “AT+CFUN”, please refer to
document [1]
.
3.6.2 GSM Sleep mode (slow clocking mode)
The SIM802 can be control module to enter or exit the SLEEP mode through DTR signal. The
DTR pin is pulled up to high level by a 10K resistor inside of SIM802 in order
to make sure the
module can enter SLEEP mode.
Figure 12: Typical connection of DTR
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