LTE Module Series
EG21-G Hardware Design
EG21-G_Hardware_Design 28 / 100
RXD
TXD
RI
DTR
AP_READY
TXD
RXD
EINT
GPIO
GPIO
Module
Host
GND
GND
Figure 3: Sleep Mode Application via UART
Driving the host DTR to low level will wake up the module.
When EG21-G has a URC to report, RI signal will wake up the host. Please refer to
Chapter 3.19
for
details about RI behaviors.
AP_READY will detect the sleep state of the host (can be configured to high level or low level
detection). Please refer to
AT+QCFG="apready"*
command for details.
“*” means
under development.
3.5.1.2. USB Application with USB Remote Wakeup Function
If the host supports USB suspension/resume and remote wakeup function, the following three
preconditions must be met to let the module enter into the sleep mode.
Execute
AT+QSCLK=1
command to enable sleep mode.
Ensure the DTR is held at high level or keep it open.
The host’s USB bus, which is connected with the module’s USB interface, enters into suspension
state.
The following figure shows the connection between the module and the host.
NOTE
