ML8011 GSM GPRS Modem User’s Manual
Page 6
GND
3,4,15
I
Power and digital ground
PWRKEY
5
I
Power on/off control
input, PWRKEY should
be pulled up for a
moment to turn on or turn
off the module.
TTL (3.3V) level, it
can be connected to the
MCU/ARM I/O port
indirectly.
STATUS
7
O
Used to indicate the
module operating status.
High level indicates
module power on and low
level indicates power off.
TTL (3.3V) level, it
can be connected to the
MCU/ARM I/O port
indirectly.
If unused, keep this
pin open.
RXD
8
I
TTL:
UART Receiving data.
TTL:
LogicL:0V
±
0.3V;
LogicH: 3.3V
±
0.3V.
TXD
9
O
TTL:
UART Transmitting data.
RI
6
O
Ring indicator
TTL (3.3V) level, it
can be connected to the
MCU/ARM I/O port
indirectly.
If unused, keep
these pin open.
CTS
11
O
Clear to sent
RTS
12
I
Request to sent
DTR
13
I
Data terminal ready
DCD
14
O
Data carrier detection
3.2 Operating modes
The table below briefly summarizes the various operating modes referred to in the following
chapters.
Table 4 Overview of operating modes
Mode
Function
Normal
operation
GSM/GPRS
SLEEP
The module will automatically go into SLEEP mode if
DTR is set to high level and there is no interrupt (such
as GPIO interrupt or data on serial port).
In this case, the current consumption of module will
reduce to the minimal level.
During SLEEP mode, the module can still receive
paging message and SMS from the system normally.
