M12 Hardware Design
M12_Hardware_Design_V3.3
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default configuration, SIM card detection function is disabled. Customer’s application can use
“AT+QSIMDET=1,0” to switch on and “AT+QSIMDET=0,0” to switch off the SIM card
detection function. For details of this AT command, please refer to
document [1]
. When
“AT+QSIMDET=1,0” is set and the tray with SIM card is removed from SIM socket, the
following URC will be presented.
+CPIN: NOT READY
When the tray with SIM card is inserted into SIM socket again and the module finishes
re-initialization SIM card, the following URC will be presented.
Call Ready
Module
SIM_VDD
SIM_RST
SIM_CLK
SIM_DATA
SIM_PRESENCE
22R
22R
22R
VDD_EXT
10K
100nF
SIM_Holder
GND
GND
ESDA6V8V6
33pF
33pF
33pF 33pF
VCC
RST
CLK
IO
VPP
GND
GND
GND
Figure 33: Reference circuit of the 8 pins SIM card
Note: Please do not use “AT+QSIMDET=1,1” which causes to initialize SIM card when the
above circuit is adopted.
If customer does not need the SIM card detection function, keep the SIM_PRESENCE pin open.
The reference circuit using a 6-pin SIM card socket is illustrated as the following figure.
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