Sim900 a gsm modem manual www.onlineTPS.com Features: Supply power: DC 9V to 12V (DC 9V typical) NOTE: Recommended power supply DC 9V/3A Onboard Features: 1. Onboard Power ON & Network indicator LED 2. Onboard indicator LED & buzzer for incoming message & call indication 3. Onboard provision to select the power on of SIM900A (either automatic or manual) using the jumper with onboard switch for manual POWER‐ON. 4. Onboard DB9 connector for connecting modem directly to computers serial port. 5. 3 pin male header (TTL) interface for connecting SIM900 directly with microcontroller. 6. Onboard Audio (speaker and microphone) interface pins. 7. Onboard PWM and ADC channels(SIM900A PWM and ADC PINS)

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SIM90
00/900
0AGSM MO M
M ODEM
Package contents:
e
¾ SIM900A GS MODEM with Antenn
SM na.
¾ DOCUMENT TATION CD.
Feature
es:
¾ Supply powe DC 9V to 12V (DC 9V typical) NOT Recomme
er: t TE: ended power supply DC 9V/3A
¾ Onboard Fea
atures:
1. O
Onboard Pow ON & Net
wer twork indicator LED
2. O
Onboard indiccator LED & buzzer for inncoming mes ssage & call indication
i
3. O
Onboard prov vision to sele the powe on of SIM9
ect er 900A (either automatic oor
m
manual) using the jumper with onboa switch for manual PO
g r ard OWER‐ON.
4. O
Onboard DB9 connector for connectin modem directly to com
9 f ng mputers seri port.
ial
5. 3 pin male he
eader (TTL) innterface for connecting S
c SIM900 direc with
ctly
m
microcontroll er.
6. O
Onboard Audio (speaker and microph
a hone) interfa ce pins.
7. O
Onboard PWM and ADC c
M channels(SIMM900A PWM and ADC PIN NS)
Note: This Manual is only for customers of www.onlinetps.com / Total Project Solutions, public
release or web publishing is prohibited without prior permission from Tot al Project Solutions – India
Product Disclaimer
The rec ommendations and s uggestions regarding product applic at ion and use that are offered on
www.onlinetps.com, in our produc t broch ures, or information provided by any employee, broker, or dis tributor of
TPS (Tot al Project Solutions), are a guid e in the use of this product and are not a guarantee to their performance s ince TPS,
has no control over the use to that other parties may apply the product. Specification may change without an y not ice.
Not suitable for critical or indu strial appli cations unless stated, please c larify any doubts before using. V1.0R0.0
Copyright © 2010 Total Project Solutions
E7/83F, Ashoka Society , Arera Colony, Bhopal 462016 (M.P.) India
e-mail: onlinetps.com@gmail.com +91-9826015410 , +91-755-2420735

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PI
INOUT:
1. DC IN Jack: D Input PIN for GSM MODEM.
DC N
2. Power Enab Switch: This is Power enable switc to Turn ON or turn OF power to t
ble ch FF the
board. When pressed tu ON the board and when released turns OFF the board
urns b d t
3. Power Indiccator LED: Modem power indicator LED.
4. EXT‐EN: Exteernal enable pin to turn ON or OFF S
es n SIM900A mo odule with exxternal contr
rolling
circuit.
5. S/W: Onboa switch to turn ON or OFF SIM900 module manually.
ard o r 0A m
6. Power ON selection jum mper: To sele the powe ON mode o the SIM90 (Manual or
ect er of 00A
Automatic)
7. RI LED and Buzzer: Incom messag and call in
B ming ge ndicator LED and buzzer.
State RI Response
Standbby High
Voice C
Call Th PIN is cha
he anged to Low when any of the follow events o
w. wing occurs the PI will
IN
chhanged to Hi igh
1..Establish the call
2..Hang up the call
e
Data ca
all Th PIN is cha
he anged to Low when any of the follow events o
w. wing occurs the PI will
IN
chhanged to Hi igh
1..Establish the call
2..Hang up the call
e
SMS Th PIN changed to LOW and kept LO for 120ms when SMS is received and then
his OW a
chhanged to HI IGH.
URC Th PIN changed to LOW and kept LO for 120ms when URC is reported and then
his OW
it is changed to HIGH.
t
8. Buzzer Enab Jumper: J
ble Jumper to en
nable or disa onboard buzzer.
able d

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9. Network Indicator LED: Network Status Indicator LED.
State SIM900 function
Off SIM900 is not running
64ms On/ 800ms Off SIM900 does not find the network
64ms On/ 3000ms Off SIM900 find the network
64ms On/ 300ms Off GPRS communication
10. ADC and PWM Pins: ADC and PWM Pins of SIM900A.(Refer page 9,10 for ADC and PWM
commands)
11. Audio Interface: Audio Pins (Speaker and microphone pins) of SIM900/900A.
12. SIM Interface: SIM Card holder Interface.
13. Vout: Regulated 4.2V output voltage for external application circuit.

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POWERI
ING SIM900/
/900A MOD
DEM:
A) POWERING SIM900/900 Modem in Automatic Mode:
0A c
Step 1: Put the jumper between ST & AUT PINS.
n P
Step 2: Connect one end of the serial Cable at the DB9 serial connec of the modem and
e s ctor m
another end at comp
puters serial port.
Insert a valid SIM card in the onboard SIMCARD holder.
Step 3: I d d h
Step 4: A V~12V DC voltage source at DC‐IN jac of SM900A modem.
Apply the 9V ck A
Step 5: N press th Power‐ON switch to turn on the b
Now he N board.

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B) POWERING SIM900/900 modem in Manual M
0A n Mode:
Step 1: P the jump between ST & MAN P
Put per PINS.
Step 2: C
Connect one end of the s
e serial Cable at the DB9 se
a erial connect of the mo
tor odem and an
nother
end at computers se
erial port.
Step 3: I
Insert a valid SIM card in the onboard SIMCARD holder.
d d h
oltage source at DC‐IN ja of SM900
Step 4: : Apply the 9V~12V DC vo
9 ack 0/900A modem.
Step 5: N press th Power ON switch to tu on the board.
Now he N urn
Step 6: N press onboard Switch (S/W) and keep it pre
Now d essed for at le 1 sec an then relea the
east nd ase
switch O apply the pulse shown below at EXT‐EN pin.
OR n
5Sec>TTON>1
HIGH
TOFF>= 1.7 Sec
LOW
NOTE: A work LED will blink at the rate of 64ms ON time/8
After power ON the netw
O s 800ms OFF Time and
once the sim900/900A modem is registered to the network the netw
e work LED will blink at the rate of
l e
64ms ON Time/3000 OFF Tim
N 0ms me.

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Conn
necting SIM90 mo
g 00A odem t Computer
to
Step 1: c
configure the Modem fo either man
or nual or auto
omatic powe ON mode using on boa
er ard
jumper and other se etting as exp
plained before in POWE 00/900A Mod
ERING SIM90 dem.
Open the computers hyp terminal application to launch the applicati goto
Step 2: O per l n, t ion
Start>Al programs>
ll >Accessories
s>Communic
cations>hype terminal
er
Step 2:
Step 3:
Step 4:
Now writ any name on the nam tab and click OK
te e me

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Now sele the COM port
ect M
Hyp
perTerminal Setting
Bau rate: 9600
ud 0
Dat Bits: 8
ta
Pari None
ity:
Stop bits: 1
p
Flow Control: None
w N
Now clic on the res
ck store default setting and click OK
t d

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Now the connection is established and you ca send the A
c s d an AT‐Comman to the GS modem
nds SM
NOT A HEX str such as “ 49 49 49 49 FF FF FF FF” will be s
TE: ring “00 9 sent out through serial po at
ort
the baud rate of 115200 imm
b f mediately aft SIM900 is powered on The string shall be ignored
ter s n. g
since it is used fo synchroniz
e or zation with PC tool. Only enter the AT commands through ser port
P y T s rial
afte SIM900/90 is power ON and unsolicited re
er 00A red u RDY” is receiv from seri port.
esult code “R ved ial
IF auuto‐bauding is enabled, the unsolicited result co “RDY” and so on are not indicat when
d, odes a e ted
usta up the ME and the “A prefix not “at” prefix must be set at the begin
art E, AT” nning of eachh
commmand line.

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ADC commands:
D m s
Note: This Manual is only for customers of www.onlinetps.com / Total Project Solutions, public
release or web publishing is prohibited without prior permission from Tot al Project Solutions – India
Product Disclaimer
The rec ommendations and s uggestions regarding product applic at ion and use that are offered on
www.onlinetps.com, in our produc t broch ures, or information provided by any employee, broker, or dis tributor of
TPS (Tot al Project Solutions), are a guid e in the use of this product and are not a guarantee to their performance s ince TPS,
has no control over the use to that other parties may apply the product. Specification may change without an y not ice.
Not suitable for critical or indu strial appli cations unless stated, please c larify any doubts before using. V1.0R0.0
Copyright © 2010 Total Project Solutions
E7/83F, Ashoka Society , Arera Colony, Bhopal 462016 (M.P.) India
e-mail: onlinetps.com@gmail.com +91-9826015410 , +91-755-2420735

10. www.onlineTPS.com
PWM commands:
W m d