Turn Off With Pwrkey; Turn Off With At Command; Reset - Quectel EC21 Series Hardware Design

 Turn off the module using AT+QPOWD. For details of the command, see document [2].

3.7.2.1. Turn off with PWRKEY

Driving the PWRKEY pin low for at least 650 ms, the module will execute power-off procedure after the
PWRKEY is released. The power-down scenario is illustrated in the following figure.

3.7.2.2. Turn off with AT Command

It is also a safe way to use AT+QPOWD to turn off the module, which is similar to turning off the module
via PWRKEY pin.
NOTE
1. To avoid damaging internal flash, do not switch off the power supply when the module works
normally. Only after the module is shut down by PWRKEY or AT command, then the power supply
can be cut off.
2. When turning off module with the AT command, keep PWRKEY at high level after the execution of
the command. Otherwise, the module will be turned on again after successfully turn-off.

3.8. Reset

The RESET_N pin can be used to reset the module. The module can be reset by driving RESET_N low
EC21_Series_Hardware_Design
Figure 13: Power-down Timing
LTE Standard Module Series
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