SimCom SIM800C, Проектирование аппаратного обеспечения

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Smart Machine Smart Decision
SIM800C_Hardware_Design_V1.02
21
2015-4-27
SIM800C can be powered off by AT command “AT+CPOWD=1”. This procedure makes the module log off from
the network and allows the software to enter into a secure state to save data before completely shut down.
Before the completion of the power off procedure, the module will send URC:
NORMAL POWER OFF
At this moment, AT commands can not be executed any more. Power off mode can also be indicated by STATUS
pin, which is at low level at this time.
For detail about AT command “AT+CPOWD”, please refer to
document [1]
.
4.2.2.3. Over-Voltage or Under-Voltage Power off
The module software monitors the VBAT voltage constantly.
If the voltage
≤ 3.5V, the following URC will be reported:
UNDER-VOLTAGE WARNNING
If the voltage ≥ 4.3V, the following URC will be reported:
OVER-VOLTAGE WARNNING
If the voltage < 3.4V, the following URC will be reported, and the module will be automatically powered off.
UNDER-VOLTAGE POWER OFF
If the voltage > 4.4V, the following URC will be reported, and the module will be automatically powered off.
OVER-VOLTAGE POWER OFF
At this moment, AT commands can not be executed any more. Power off mode can also be indicated by STATUS
pin, which is at low level at this time.
4.2.2.4. Over-Temperature or Under-Temperature Power off
The module will constantly monitor the temperature of the module,
If the temperature
≥ +80
℃
, the following URC will be reported:
+CMTE: 1
If the temperature ≤ -30
℃
, the following URC will be reported:
+CMTE:-1
If the temperature > +85
℃
, the following URC will be reported, and the module will be automatically powered
off.
+CMTE: 2
If the temperature < -40
℃
, the following URC will be reported, and the module will be automatically powered
off.
+CMTE:-2
At this moment, AT commands can not be executed any more. Power off mode can also be indicated by STATUS
pin, which is at low level at this time.
Note
：
The default temperature detect is disable, AT command “AT+CMTE” could be used to read the
temperature when the module is running.For details please refer to document [1].
4.2.2.5. Restart SIM800C by PWRKEY Pin:
When the module works normally, if the customer wants to restart the module, follow the procedure below:
1)
Power off the module.
2) Wait for at least 800ms after STATUS pin changed to low level.