ETT ET-BASE GSM SIM900 User manual
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ET-BASE GSM SIM900
http://www.etteam.com
Electronics Technology Team
บริษัท อีทีที จำกัด
ETT CO., LTD.
Manual of Board ET-BASE GSM SIM900
CONTENTS
1. Specifications of Board ET-BASE GSM SIM900 3
2. Initial Specifications of Module SIM900 3
3. Co positions of Board ET-BASE GSM SIM900 4
4. How to Enable/Disable Operation of Module SIM900 6
5. How to Co unicate with Module SIM900 7
6. Noteworthy Specifications of Signal 9
7. Exa ple of using AT Co and with Module SIM900 9
8. How to Test Operation of Board ET-BASE GSM SIM900 10
9. Exa ple of Using Co and about RS232 13
10. How to Setup and Check Configuration 15
11. How to Check Data of Module SIM900 16
12. How to Make, Receive, and Cancel a Call 17
13. How to Check Balance by USSD 18
14. How to Receive SMS 19
15. How to Send English SMS 20
16. Code of Thai SMS 21
17. Principles of Decoding Unicode 23
18. How to Send Thai SMS 26
19. How to Use SIM Co and (SIM Application Toolkit: STK) 28
20. How to Read Data fro Website by GPRS Connection (HTTP GET) 32
21. How to Connect Board ET-BASE GSM SIM900 with Board Microcontroller 34
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Manual of Board ET-BASE GSM SIM900
ET-BASE GSM SIM900
ET-BASE GSM SIM900 is a kit to learn and develop wireless
co unication by using Module GSM/GPRS odel SIM900 fro SIMCo to
be ain device; this SIM900 is a s all GSM/GPRS Module that supports
GSM Frequency in the range of 850/900/1800/1900MHz. It co unicates
through Port RS232 by AT Co and; it can be applied for various
applications such as trans itting/receiving signal in the for at of
Voice, SMS, Data, FAX, including Protocol TCP/IP Co unication.
Nor ally, it provides the Circuit and Fir ware internal Module
SIM900 co pletely but it is not ready to use because user has to
design the circuit of Peripheral device that is necessary to connect
with so e partial Pin of Module such as Circuit Power Supply,
circuit for connecting with SIM Card, including Circuit Line Driver
of RS232. So, ETT Tea provides the inter ediate board to connect
between Module SIM900 and external device, it assists custo er to
learn and test the operation conveniently before odifying and
adapting this Module for any application in the future. Although all
connective circuits that are provided by ETT Tea cannot support all
resources internal Module, it can support the ain capability of
this Module efficiently.
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Manual of Board ET-BASE GSM SIM900
1. Specifications of Board ET-BASE GSM SIM900
•Has Push-Button Switch to Enable/Disable the operation of
Module internal board
•Has Push-Button Switch to reset the operation of Module
internal board
•Has Socket SIM to support SIM Card with Circuit ESD to protect
SIM fro da aged
•Has 2 of isolated Regulates that can be used with Adapter 5-
12VDC; it can provide current for Module SIM900 and connective
devices enough.
oHas Circuit Regulate 4.2V/3A that can supply to Module
SIM900 enough, it can be used with SIM of GSM900MHz 2-
Watt without any proble
oHas Circuit Regulate 2.8V/150 A to supply to the circuit
that converts Signal Logic.
•Has Circuit Line Driver to convert Signal Logic fro Module
SIM900 into RS232 (1200bps-115200bps) for port co unication
that is used to co and Module.
•Has circuit to convert Signal Logic TTL 3V-5V to directly
connect with Microcontroller, without connecting through
Circuit Line Driver RS232
•Has LED to display the ready status of board; status of Power
Supply, status of Module, status of Network Connection, and
status of Power-ON/Power-OFF of Module
•Has Connector to connect with Handset ( icrophone and speaker
of ho e phone); it uses Connector Standard RJ11with Circuit
Voice Filter. In this case, it can interface Handset of ho e
phone with board through Connector RJ11 to ake and receive a
call conveniently.
2. Initial specifications of Module SIM900
•Support Frequency in the range of GSM/GPRS 850/900/1800/1900MHz
•Support GPRS Multi-Slot Class10 and GPRS Mobile Station Class B
•Support standard AT Co and (GSM 07.07/ 07.05 and additional
co ands fro SIMCOM)
•Support SIM Applications Toolkit
•Run by the Frequency in the range of 3.2V to 4.8V
•Support external connection
- Be co patible with SIM Card 1.8V and 3V
- Has Circuit Analog Audio (MIC & Speaker)
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Manual of Board ET-BASE GSM SIM900
3. Co positions of Board ET-BASE GSM SIM900
•No.1: It is Connector Power Supply for board, there are 2
types. Firstly, it is DC JACK that is Anode-OUT(+) and Cathode-
IN(-); secondly, It is Connector JST. The Power Supply that
provides for board is 5-12VDC with at least 2A Current.
•No.2: It is Connector RS232 4PIN (ETT Standard); it interfaces
with device that trans its/receives data by RS232 such as
co puter or Board Microcontroller, especially be connected
through Circuit Line Driver RS232. It arranges signal pins as
shown in the picture below;
•No.3: It is Connector TTL 3.5V to connect with Microcontroller
directly, without interfacing through Circuit Line Driver
RS232. It arranges signal pins as shown in the picture below;
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Manual of Board ET-BASE GSM SIM900
Pin Na e Direction Description
PWRKEY INPUT Control ON/OFF Module SIM900, it runs by
Logic “1”
STATUS OUTPUT Report that status of Module SIM900 is
active. If it is Logic “1”, the Module is
active; or, if it is Logic “0”, the Module
is inactive or it is the status of Power
Down.
NRESET INPUT Reset operation of Module SIM900, it runs
by Logic “1”
RXD INPUT Receive data
TXD OUTPUT Trans it data
RTS INPUT Request to send
CTS OUTPUT Clear to send
DCD OUTPUT Data carrier detect
DTR INPUT Data ter inal ready
NC - Unused
GND Ground
•No.4: It is Connector RJ11 to connect with Handset in order to
use the Module SIM900 to ake and receive a call. It can
interface with general standard of Handset.
•No.5: It is Ju per to choose if user requires connecting Pin
RXD,TXD of Module through Circuit Line Driver RS232. If user
requires connecting pins through Connector RS232, it has to set
Ju per JP2 and JP3 to the position of 232; or, if user requires
connecting pins through Connector TTL P4,P5, it has to set
Ju per JP2 and JP3 to the position of TTL.
•No.6: It is Push-Button Switch to reset the operation of
Module.
•No.7: It is Push-Button Switch to Power-ON and Power-OFF the
Module.
•No.8: It is Ju per to auto-enable the operation of Module
SIM900 i ediately after supplying power into board; it has to
set Ju per to the position of AT. If user requires using Switch
ON/OFF or Pin PWRKEY to control ON/OFF, it has to set this
Ju per to the position of Pin 1-2.
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Manual of Board ET-BASE GSM SIM900
•No.9: It is LED to display the operating status of board as
described below;
LED VBAT: It displays status of external Power Supply that
is connected with board. This LED is lit up when it supplies
power into board co pletely.
LED NET (NETLIGHT): It displays status of Module while
connecting with network. This LED is controlled by Signal
NETLIGHT (PIN 52) of Module SIM900. It is Logic “1”when it
is active. When the Module is ready to operate, this LED
flashes with different speeds as described below;
oOFF: Module is in the status of Power OFF (inactive).
o64 S ON/ 800 S OFF: Module SIM900 cannot find out any
network.
o64 S ON/ 3000 S OFF: Module SIM99 found the network
successfully.
o64 S ON/ 300 S OFF: Module SIM900 is in the progress of
connecting with network or other devices by GPRS.
LED STAT (STATUS): It shows whether the status of Module
SIM900 is active. If LED is lit up, it eans that the Module
is active; or, if this LED is off, it eans that this Module
is inactive or, it is in the status of Power Down Mode.
•No.10: It is Connector Antennae GSM with the Frequency in the
range of 850/900/1800/1900MHz.
•No.11: It is Socket to install SIM Card on Module.
•No.12: It is Module SIM900.
4. How to Enable/Disable Operation of Module SIM900
Nor ally, Module SIM900 has several odes to enable and disable
the operation of Module as described below;
4.1 Switch ON/OFF(SW1): It enables/disables the operation of
Module SIM900 by pressing Push-Button Switch. It sets Logic
status for Pin PWRKEY (PIN 1) of Module; it is Logic “0” when
it presses the switch; or, it is Logic “1” when it releases
the Switch. Re e ber, user has to continue pressing the Switch
ore than 1000 S (1 second) and it has an effect on the
operation of Module. This Switch runs in the for at of Toggle;
if the Module is in the status of Power OFF and user presses
and holds the Switch ore than 1000 S (1 second), it co ands
the Module return to the status of Power ON that is ready to
operate. Or, if the Module is in the status of Power ON and
user presses and holds the Switch ore than 1000 S (1 second)
and then releases the Switch, it co ands the Module to stop
running and return to the status of Power OFF (stop running).
Status of LED is listed in the Table below;
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Manual of Board ET-BASE GSM SIM900
LED Status Power-ON Power-OFF
VBAT (GREEN) ON ON
NET(ORANGE) FLASH OFF
STAT(GREEN) ON OFF
Table shows status of LED in various odes.
4.2 Control On/OFF by Pin PWRKEY: It enables/disables the
operation of this Module by external signal such as signal
fro Microcontroller; it is connected through Pin PWRKEY
(Connector P4 or P5). It runs in the for at of Toggle; if the
Module is in the status of Power OFF and it sends Logic “1”
ore than 1000 S (1 second) and then it beco es Logic “0”, it
co ands the Module to return the status of Power ON that is
ready to run. Or, if the Module is in the status of Power ON
and it sends Logic “1” ore than 1000 S (1 second) and then it
beco es Logic “0”, it co ands the Module to stop running and
return to the status of Power OFF (stop running).
4.3 Auto ON/OFF: It auto enables the operation of Module SIM900
i ediately after supplied power into Board ET-BASE GSM SIM900
co pletely; in this case, it has to set Ju per JP1 to the
position of AT.
5. How to co unicate with Module SIM900
There are 2 types to co unicate with Board ET-BASE GSM SIM900.
Firstly, it is connected through RS232 Serial Port by Connector 4PIN
that is arranged according to ETT Standard; it can be connected with
standard Signal RS232 such as co puter RS232 (Co Port) or ETT Board
Microcontroller that is Connector RS232 4PIN instantly. Secondly,
this Board ET-BASE GSM SIM900 provides Connector TTL 3-5V (P4 or P5)
to interface with Board Microcontroller directly, without using any
Circuit to convert the signal level to be RS232. Signals that are
used to serially connect with Module SIM900 are listed as follows;
•DCD(Data Carrier Detect) of Module SIM900 is Output fro
SIM900; nor ally, it is interfaced with DCD Input of the device
on the Host side.
•TXD(Trans it Data) of Module SIM900 is Output fro SIM900;
nor ally, it is interfaced with RXD(Receive Data) of the device
on the Host side.
•RXD(Receive Data) of Module SIM900 is Input fro SIM900;
nor ally, it is interfaced with TXD(Trans it Data) of the
device on the Host side.
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Manual of Board ET-BASE GSM SIM900
•DTR(Data Ter inal Ready) of Module SIM900 is Input fro SIM900;
nor ally, it is interfaced with DTR of the device on the Host
side.
•RTS(Request To Send) of Module SIM900 is Input fro SIM900;
nor ally, it is interfaced with RTS of the device on the Host
side.
•CTS(Clear To Send) of Module SIM900 is Output fro SIM900;
nor ally, it is interfaced with CTS of the device on the Host
side.
•RI(Ring Indicator) of Module SIM900 is Output fro SIM900;
nor ally, it is interfaced with RI of the device on the Host
side.
•GND of Module SIM900 ust be interfaced with GND of the device
on the Host side.
It illustrates how to interface Signals between ET-BASE GSM SIM900
and Microcontroller.
Table shows the full connection.
Table shows the connection by 3 Cables.
NOTE: In case of using 3 Cables for connection (RXD, TXD,
GND), it has to setup the condition of Flow Control for Module
SIM900 as No flow control by using the Co and “AT+IFC=0,0”, or
XON/XOFF by using the Co and “AT+IFC=1,1”.
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Manual of Board ET-BASE GSM SIM900
6. Noteworthy Specifications of Signal
•RI(Ring Indicator) is Output fro Module SIM900; nor ally, it
is High, but it beco es Active Low when there is an inco ing
telephone call according to these conditions;
oWhen there is any Voice Calling, Signal RI is Active LOW
and it still re ains until it answers a calling (ATA) or
it receives a co and to cancel a calling (ATH) or it
hangs up a telephone before answering.
oWhen there is any Data calling, Signal RI is Active LOW
and it still re ains until it answers a calling (ATA) or
it receives a co and to cancel a calling (ATH).
oWhen there is SMS, Signal RI is Active LOW for 120 S and
it beco es HIGH auto atically.
•DTR(Data Ter inal Ready) is Input of Module SIM900. The Module
runs when this Pin receives Logic LOW; but, it this Pin DTR
receives Logic HIGH, the Module stops running and enters Sleep
Mode auto atically (if Enable Sleep Mode by Co and
“AT+CSCLK=1”). If user requires running the Module all the
ti e, it has to control Pin DTR on the Module side to receive
Logic LOW or it has to disable Sleep Mode by Co and
“AT+CSCLK=0” and then save this Configuration.
7. Exa ple of using AT Co and with Module SIM900
Module GSM/GPRS odel SIM900 is designed and run as Mode , it
is used to connect, co and, and co unicate with Module through
RS232 Serial Port; it supports Baud Rate in the range of 1200-115200
bps and it uses AT Co and. Its functions are si ilar to general
Mode but it adds Option and other special co ands, so it is
suitable and co patible with capability of Module.
Please read further details of for at and function of AT
Co and in order to connect and co and Module SIM900 fro the
anual of AT Co and (file docu ent SIM900_AT Co and
Manual_V1.06.pdf) in CD-ROM. In this case, it only describes for at
and how to use co ands briefly to be guideline for beginner to
study and understand the co and. The for at of AT Co and begins
with ASCII Code of 2 characters that are “A” and “T”; in this case,
it can be either capital letter or s all letter because the eaning
is the sa e. Next, it follows by Co and Code and Option of co and
(if yes). Re e ber, every co and always ends by Enter or 0DH(13);
for exa ple, the for at of Co and RESET is either “ATZ” or “atz”.
The co and for at is divided into 4 groups as follows;
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Manual of Board ET-BASE GSM SIM900
Function For at of
Co and
Description
Test co and AT+<x>=? This co and for at is used to read
for at and para eter of co and. If the
co and actually exists, the Module
acknowledges the co and by typing all
existing para eters of co and.
Read Para eter AT+<x>? This co and for at is used to read
para eters that have been setup for the
co and. The Module acknowledges the
co and by typing current para eters.
Setup
Configuration
AT+<x>=<…> This co and for at is used to write or
setup para eters for co and such as
setup Baud Rate.
Execute AT+<x> This co and for at is used to co and
the Module to execute according to the
preferable co and such as Co and RESET
(ATZ).
Table shows for at of using AT Co and (when <x> is Co and Code).
8. How to test operation of Board ET-BASE GSM SIM900
As entioned above, it sends the Co and Code in the for at of
AT Co and to Module SIM900 through Serial Port. Nor ally, custo er
needs to write progra to send Co and Code into the Module by self,
it depends on type of controller device that is used to control the
operation of odule; in this case, it ay be co puter PC or
Microcontroller in any series that has RS232 Serial Port in order to
connect and co and Module SIM900. Moreover, it depends on ability
or basic skill of user to choose any way and language to write
progra because it needs user with know-how to write progra to
co and the device in order to trans it/receive data through RS232
Serial Port, this anual does not describe any detail of the .
Initially, it is unnecessary to write progra , but user can use
ready- ade progra such as Progra Serial Ter inal of co puter to
test the operation; oreover, user can learn and understand the
co and for at and operating result well. For exa ple, if co anding
the Module SIM900 to ake a call to the telephone nu ber 0811234567,
user has to learn and understand the co and for at first; when user
knows and understands how to use the Co and “ATD0811234567;” to
ake a call, user can write the progra to co and the Module by
self later. Next, user needs to exactly know how to write progra to
co and the device to send Code “ATD0811234567;” through Serial
Port; in this case, it suggest Progra HyperTer inal fro Windows to
be a tool to initially test, this Progra HyperTer inal is ready-
ade progra that is provided with Windows Operating Syste .This
progra has several interesting parts because there are various
capabilities to do; in this case, it only uses the part of function
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Manual of Board ET-BASE GSM SIM900
Serial Ter inal in Text Mode. After RUN progra , any data that is
received fro RXD of Serial Port in the range of ASCII Code (20H…
FFH) will be converted to be character and displayed on the screen
of progra instantly. For other Data Code that is lower than 20H
(00H-1FH), it is not displayed on the screen but it auto atically
assu es that it is co and. For exa ple, when it receives the Data
Code as ODH, Progra HyperTer inal assu es that it is the co and to
shift the Cursor position to the beginning of line; or, when it
receives the data Code as 0AH, it shifts the Cursor position to the
new line instead. On the contrary, when user presses any key,
Progra assu es that it is ASCII Code of character at the position
that the key is pressed and it auto sends to Pin TXD of Serial Port.
However, if using Windows7 or Windows8, there is no any Progra
HyperTer inal; so, this exa ple illustrates how to use Progra Tera
Ter instead as described below;
8.1 Install and open Progra Tera Ter , choose the connection
as Serial, choose Port to interface with ET-BASE GSM SIM900, and
then click OK as shown in the picture below;
8.2 Click Menu Setup-->Serial port… to setup value of Port
RS232. In this case, it has to choose Baud Rate according to the
actual connection with Module. If setting Baud Rate of Module as
Auto-Baud Rate, user can choose any Baud Rate that the Module
supports such as 1200, 2400, 4800, 9600, 19200, 38400, 57600, or
115200; in this case, it chooses 115200. In the part of Data, it
sets the value as 8 Bit, Parity = None, Stop bits = 1, Flow Control
= None; and finally, choose “OK” as shown in the exa ple below;
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Manual of Board ET-BASE GSM SIM900
8.3 After setup the connection successfully and everything is
correct, user can connect Cable RS232 between Board and Co port of
co puter PC (it has to set Ju per JP2,JP3 to the position of RS232),
and then supplies power into board co pletely. If everything is
correct, user can see green LED VBAT on board is lit up. Next, it
sets Power-ON Module by pressing and holding Switch ON/OFF for 1
second, user can see LED STAT (STATUS) is lit up and LED NET
(NETLIGHT) starts flashing all the ti e, it eans that the Module
starts running. Moreover, it shows essage on the screen of Progra
Tera Ter , user needs to wait for a while until it shows the essage
“Call Ready”, it eans that the Module searched and found the
Network successfully. Next, user can co and the Module to execute
by Co ands as required.
If there is no any essage on the screen of Progra
HyperTer inal, it ay setup Baud Rate of Module SIM900 as Auto-Baud
Rate, so the Module auto adjusts the Baud Rate. This Auto-Baud Rate
is set by anufacturer. In this case, user types the character AT
(only capital letter) and then presses Enter, the Module responds
“OK” as shown in the picture below, and now the Module is ready to
run.
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Manual of Board ET-BASE GSM SIM900
If user would like to show the essage “Call Ready” to the
screen, it has to set fixed Baud Rate of board by Co and
AT+IPR=115200 and then press Enter; this Co and setup Baud Rate as
115200 bps. Next, user tries to close and re-open the Module, the
essage “Call Ready” appears on the screen, and the Module is now
ready to run.
9. Exa ple of using Co and about RS232
In this case, it illustrates exa ple of Co and that is
frequently used; for ore infor ation, please read fro the file
docu ent SIM900_AT Co and Manual_V1.06.pdf.
9.1 Exa ple of using Co and to setup Baud Rate
It uses Co and AT+IPR to setup Baud Rate for the co unication
of Module. There are various ways to execute this co and.
Firstly, if user forgets what available Para eter of co and or
Baud Rate is, and including how to setup the value, it uses
Co and AT+IPR=? and follows by Enter to ask for ore
infor ation. The Module responds +IPR: and types the all
available Para eters of the Co and that are 0, 300, 1200, …,
115200 as shown in the exa ple below (the black essage is
co and that is put in to ask for and the red essage is the
response that the Module answered).
!!"#!#$!$%!&!"#!'%$!()&!""(#
*+
If user would like to know what the current Baud Rate is, it
uses the Co and AT+IPR? to read Para eter of this co and. The
Module responds +IPR: and follows by the current Para eter as
shown in the exa ple (0=Auto Baudrate).
*+
Referred to the exa ple above, the Para eter of the Co and IPR
is “0” that is Auto-Baud Rate, so the Module auto adjusts the
Baud Rate when it initially starts first ti e. If user would
like to set the fixed Baud Rate for the Module to keep running
with this fixed Baud Rate all the ti e, it can do it by using
the co and for at to setup. For exa ple, if setting Baud Rate
as 115200, it uses the co and for at as AT+IPR=115200 and then
follows by Enter as shown in the exa ple below;
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Manual of Board ET-BASE GSM SIM900
""(#
*+
After changed the Baud Rate as 115200 co pletely, it can
co unicate with Module by this fixed Baud Rate all the ti e.
9.2 How to set Flow Control
It can setup Flow Control or the for at of checking if the
Module SIM900 is ready to co unicate and trans it/receive
data. This Flow Control is i portant because speed of
processing data of each device is different. When it
receives/trans its a lot of data continuously but the receiver
is not ready to receive any data yet while the trans itter
continues trans itting data, so e data ay lost and error
happens. This SIM900 supports 2 types of Flow Control as
entioned below;
•Software Flow Control (XON/XOFF Flow Control): It uses
Software to check if the Module SIM900 is ready. It uses
Code XOF(13H) to stop trans itting data fro the trans itter
and it uses Code XON(11H) to notify or per it the
trans itter to trans it the next data to the Module. This
Flow Control type is suitable for connecting with the device
that has no any Flow Control such as Microcontroller or
device only uses 3 Cables (RXD, TXD and GND).
•Hardware Flow Control (RTS/CTS Flow Control): It uses
Hardware to check if Module SIM900 is ready. It uses
Active(“LOW”) Signal CTS to notify the trans itter to stop
trans itting data when the Module is not ready to receive
any data. On the contrary, it checks if the status of RTS is
Active before trans itting data; if it is Active, it eans
that the receiver is not ready to receive any data and user
needs to stop and wait until the status of RTS beco es
“HIGH”.
When Flow Control is set as No Flow Control, it uses Co and
AT+IFC=0,0 (Default value).
When Flow Control is set as XON/XOF, it uses Co and AT+IFC=1,1
When Flow Control is set as RTS/CTS, it uses Co and AT+IFC=2,2
9.3 How to setup Data For at of RS232
User can setup Data For at as required; in this case, user can
deter ine what for at of trans itting data is, what size of
data bit is, whether it checks Parity Bit, and how any Stop
Bit is. Nor ally, it sets Data 8 Bit, None parity, 1 Stop Bit.
However, user can change and edit this Data For at by Co and
AT+ICF.
It uses Co and AT+ICF=3,3 to setup Data For at as 8 Bit Data, None
Parity, 1 Stop Bit.
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Manual of Board ET-BASE GSM SIM900
9.4 How to Enable/Disable Echo
Echo is the return of a trans itted co and to its source when
user typed co ands on Progra Ter inal to notify user to know
what the typed and trans itted co and is (nor ally, it is
Default value). If user would like to disable this function, it
uses Co and ATE0&W and follows by Enter; when user types the
co and, user does not see it on Progra Ter inal because it
only displays the response fro Module SIM900. If user would
like to enable this function, it only uses the Co and ATE1&W
and follows by Enter.
10. How to Setup and Check Configuration
Nor ally, there are several ways to setup Configuration of
Module SIM900 such as conditions of co unicating with Module;
oreover, user can change and edit values as required such as Baud
rate or for at of Handshakes for co unication. Re e ber, it is
necessary to setup Configuration of the Module to suit user’s needs.
Nor ally, these conditions always have a fixed value after resetting
or Power ON; the Module sets conditions for its own when it starts
running by the values that are setup and saved in Configuration.
However, user can change and edit this Configuration as required.
There are 2 ways to setup conditions of the Module as described
below;
•Per anently Setup: It saves conditions of Module according to
the setting for at in the per anent e ory internal Module by
Co and AT&W. After Module starts running or after reset Module
in each ti e, the conditions of the Module always are set
according to the saved values in Configuration.
•Te porarily Setup: It uses AT Co ands to setup condition for
running Module but is does not save any Configuration by the
Co and AT&W; so, the operation of Module also changes and
varies according to the current co and. When reset the Module
or Power ON, the specification of Module also return to the old
one instantly.
It can use AT Co and to check and save Configurations into Module
SIM900 as follows;
•It uses Co and AT&V to co and the Module to show the current
Configuration.
•It uses Co and AT&F to reset all Configurations to be standard
value.
•It uses Co and AT&W; it saves the current Configurations that
are setup by user.
Suggested Configuration
•AT+CMGF=1 (SMS Message = Text Mode)
•ATE=1 (Echo Mode ON)
•AT+CSCLK=0 (Disable Sleep Mode)
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Manual of Board ET-BASE GSM SIM900
11. How to check data of Module SIM900
11.1 How to check signal quality
It uses the Co and , to check signal quality; this
co and is used to check the strength of signal. The odule responds
the nu eric value 0…31 or 00. If it is in the range of 2…30, it
eans that the signal is good; or, if it is 31, it eans that the
signal is excellent; or, if it is 99, it eans that it cannot check
any signal as shown in the exa ple below;
,
,"&!
*+
11.2 How to check Product ID
""-
*+
11.3 How to check Manufacturer ID
.
*/01
*+
11.4 How to check odel code
.
*/
*+
11.5 How to check Fir ware Version
.
23""')4"&$//5
*+
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Manual of Board ET-BASE GSM SIM900
11.6 How to check Serial Nu ber(IMEI) of Module
.6
"#%&""%($(
*+
11.7 How to check SIM Network Code of facilitator
*
*!!78.7
*+
12. How to ake, receive, and cancel a call
•It uses the Co and ATD to ake a call; the for at of co and
is to follow by the destination nu ber
•It uses the Co and ATDL to ake a call; it uses the telephone
nu ber that user has recently ade a call.
•It uses the Co and ATA to receive an inco ing telephone call.
When there is an inco ing call, user can hear ringtone fro
speaker (receiver) of handset; in this case, user can use the
Co and “ATA” to receive a call and speak instantly through
Handset or icrophone (trans itter) of ho e phone.
•It uses the Co and ATH to hang up a telephone or cancel a
call.
This is an exa ple of aking a call by VOICE, it has to end the
co and by se icolon sign (;) and Enter (0x0D); for exa ple, when it
akes a call to the telephone nu ber 0894469xxx, it is
%$$&999:
*+
If it akes a call but it does not answer the telephone or the
line is busy, the Module reports by the essage “BUSY” as shown in
the exa ple below;
%$$&999:
*+
4;
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Manual of Board ET-BASE GSM SIM900
This is an exa ple of checking balance of 1-2-CALL. If it is
general cell phone, it only types “*121#” and call; but, if it is
Module SIM900, it has to use the Co and ATD and follows by the sign
instead as shown in the exa ple below;
<"#"=
*+
!7> ? @ %)&%"999 3 """-&# 4- A 21 B 'C(C"'
D(4-.'.C.)4E>)1D391BFGF-33<(<)=7!&$
This is an exa ple of receiving a call. When there is an
inco ing telephone call in case of using Module SIM900, it shows the
essage “RING” and user can hear ringtone fro speaker (receiver) of
handset. It uses the Co and ATA in order to receive a call, or it
uses the Co and ATH to hang up or cancel or reject an inco ing call
as shown in the exa ple below;
6.
*+
It uses the Co and AT+CLIP=1 and follows by Enter in order to
show an inco ing telephone nu ber, the Module will show the inco ing
telephone nu ber as shown in the exa ple below;
6.
0H%$$&999I!"#!II!!II!
13. How to check balance by USSD
It also uses the Co and AT+CUSD and follows by USSD
(Unstructure Supple entary Service Data) to check balance. The
exa ple below shows how to check balance in case of 1-2-CALL.
"!7<"#"=7
*+
!7> ? @ %)&%"999 3 """-&# 4- A 21 B 'C(C"'
D(4-.'.C.)4E>)1D391BFGF-33<(<)=7!&$
ETT CO., LTD. -18- www.ettea .co
Manual of Board ET-BASE GSM SIM900
14. How to receive SMS
Nor ally, Module SIM900 can set 2 operation odes for essage
or SMS that are PDU Mode and Text Mode. Firstly, it is PDU Mode; it
receives and displays the operation of co and in the for at of
Binary Code. Secondly, it is Text Mode; it receives and displays the
operation of co and in the for at of text. In this case, Text Mode
is easier than PDU Mode because it is easier to co pile and
understand. This illustrates an exa ple of Text Mode.
•It uses the Co and AT+CMGF=1 to set the data for at as Text
Mode; when it sends SMS to Module, it shows essage to notify
user.
For exa ple, if the essage as +CMTI: “SM”,3 appears, it eans
that there is an inco ing essage and it is saved in the third
order of the e ory.
•It uses the Co and AT+CMGR to read essage. For exa ple, if
user requires reading the essage in the third order, it has to
use the Co and as AT+CMGR=3.
•It uses the Co and AT+CMGL="ALL" to show all essages that are
saved in the e ory; in this case, use can choose type of
essage as required such as new essage or all essages.
•It uses the Co and AT+CMGD to delete essage fro the e ory.
For exa ple, if user requires deleting the essage in the third
order, it has to use the Co and as AT+CMGD=3.
•It uses the Co and AT+CMGDA=”DEL ALL” to delete all essages
fro the e ory.
This is an exa ple of receiving SMS by sending the essage “Hello
12345” to Module SIM900B. When it received the essage co pletely,
it shows the essage text+CMTI: “SM”,n; in this case, n eans the
order of essage.
77!'
.'
.767!7&&%$$&9997!!7)C""C"!"'##(#%7
8"#'$(
*+
If user re-reads the old essage repeatedly, the status of
essage beco es “REC READ” instead to notify user to know that this
essage has been read co pletely as shown in the exa ple below;
.'
.77!7&&%$$&9997!!7)C""C"!"'##(#%7
8"#'$(
*+
ETT CO., LTD. -19- www.ettea .co
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