To avoid damages to the internal flash, DON'T cut off the power supply before the module is completely
turned off by pulling down FULL_CARD_POWER_OFF# pin for more than 900 ms, and DON'T cut off
power supply directly when the module is working.
3.3.3. Monitor the Power Supply
AT+CBC command can be used to monitor the voltage value of VCC.
3.4. Turn on
FULL_CARD_POWER_OFF# is used to turn on/off the module or reset the module through hardware
reset. This input signal is 3.3 V tolerant and can be driven by either 1.8 V or 3.3 V GPIO. And it has
internally pulled down with a 100 kΩ resistor.
Table 8: Definition of FULL_CARD_POWER_OFF#
When FULL_CARD_POWER_OFF# is de-asserted (driven high, ≥ 1.19 V), the module will turn on