Data Sheet

Smart Machine Smart Decision
SIM800F_Hardware Design_V1.00 25 2015-07-31
If the temperature > +85℃, the following URC will be reported, and the module will be automatically powered
down:
+CMTE: 2
If the temperature < -40℃, the following URC will be reported, and the module will be automatically powered
down:
+CMTE:-2
At this moment, AT commands can not be executed any more, and only the RTC is still active. Power off mode
can also be indicated by STATUS pin, which is at low level at this time.
The AT command “AT+CMTE” could be used to read the temperature when the module is running.
For details please refer to document
[1]
.
4.2.3 Restart SIM800F by PWRKEY Pin
When users need to power off the module then restart it, please follow the procedure below:
1) Power off the module
2) Wait for at least 800ms after STATUS pin changed to low level
3) Power on the module
Figure 14: Timing of restart SIM800F
4.3 Reset Function
SIM800F provides a reset pin (pin 16) to reset the module. This function is used as an emergency reset only
when AT command “AT+CPOWD=1” and the PWRKEY pin do not work. Pull the RESET pin to ground, then
the module will reset.
This pin is already isolated from the chipset inside the module, so the external isolation is not necessary.
Following figure shows the internal circuit:
Figure 15: Reset Circuit