Hi, I buy SIM908 module but can not find anywhere to explain its operation and connection with arduino .can you help me ?
Thanks.
I guess phone is same as SIM900/900A
Pins are marked RX/TX, Vcc (near 4V) and GND
Add SIM. blink every .8sec until connected to network - then blink every 3 sek
In middle of this page, u'll find an "online command tester"
http://m2msupport.net/m2msupport/software-and-at-commands-for-m2m-modules/
connect phone via usb<->serial adapter
Hi
I have bought the same GPRS and GPS board but with no documentation or sample code. I'll let you know if I find something.
olle@oversea.nu
All GPS modules support the NMEA interface, which is a serial data stream. So long
as to level convert (this is seemingly not a 5V device) you just listen/talk to it with
Serial or SoftwareSerial.
If the OP looks on the product page they linked to it has a link to a .rar file with documentation & schematics.
I have tried every possible setup!?
TX on Leonardo to TX on GPRS board and RX to RX
RX on Leonardo to TX on GPRS board and TX to RX
Used every suggested SoftwareSerial, 3 4, 7 8 9, 10 11, ...
Always with GND to GDN connected
Supply is 9V with 1A
Tried it on 20 different sample codes but....
I never get any response from the GPRS board. It-s connected to the net (blinka every 3 sec)
A simple thing as sending AT and get OK back, no.....
Hi,
Had the same issue, finally solved it!!!
Baud: 115200
Data bits: 8
Stop bits: 1
Parity: None
Flow Control: None
Connect GPRS TX/RX and GND
The missing part to your pain......
Connect a DC 3.3v source to pin VCC_MCU (along side your main DC 5v 1A input source)
Now you should get your 'OK', ok! 
Howser
So if I understand you correctly.
GPRSTXD to Arduino D7
GPRSRXDto Arduino D8
GND to GND
GPRS VCC_MCU to Arduino 3,3V
In the code do:
gprsSerial.begin(115200); // GPRS shield baud rate
How do I set the following??
Data bits: 8
Stop bits: 1
Parity: None
Flow Control: None
8-N-1 is the default setting. And I'm not sure you can change it easily.
You might want to try getting hold of the schematics for one of the SIM908 based shields and look at how they are connected to the Arduino?
Hi everybody,
you don't need to set baudrate and flow control because the module starts with a default baudrate of 115200 and there is no reason to modify it.
So if you want to use the arduino Serial Monitor to send AT cmd you simply have to set it at 115200 baudrate.
The wiring is really simple.
If you want to have a real time interaction with the modem by AT cmd:
// Arduino - RX --> module connector J6 GPRS-TXD (output from GPRS to Serial Monitor)
// Arduino - TX --> module connector J5 GPRS-RXD (cmd from Serial Monitor to GPRS)
// Arduino - GND --> module connector J5 GND
Note: you can get 5v power for Arduino directly from the module connecting Arduino VCC and Arduino GND to module connector J2 +/-
If you want to create a sketch the wiring is the same and you have to write a function to send AT cmd to the modem and read the response.
You have to open a serial connection 115200 and send AT cmd by the function Serial.println(ATcommand) and read the answer by the function Serial.read().
Hi. I am working motiondetectalert system and want to add sms alert also in this system. I have this same module but couldnt get it working.
Has anyone got this module working with Arduino and could past here example code and scematichs, please. ?
Best Regards Tuomo Vuorinen
Finland
Hi, i have this module.
Note: you can get 5v power for Arduino directly from the module connecting Arduino VCC and Arduino GND to module connector J2 +/-
- Sorry but is write on the board 3.5 -- 4.2V. If i apply 5V, board break???
- When i press PWRKEY for 1 second and release, GMS module shut down.. why?
I have connected
VBAT+ to 5V arduino
VBAT- to GND arduino
Hi. I just wanted to info u that I got this sim908 working. D-sun USB to TTL shifter (http://www.cpmspectrepi.webspace.virginmedia.com/raspberry_pi/MoinMoinExport/USBtoTtlSerialAdapters.html the red one!)
came with the board and I tested it with it and it worked.
TTL shifter was connected straight to my PC and I used ONLINE AT commender to test it. Here is screencapture of the happening. At first it worked just once, but after rebooting sim908 board now it working all the time and answering all the questions that are sended.
wiring:
USB to TTL SIM908
3.3V ----------------------------- VCC_MCU
TX-----------------------------------GPRS RXD
RX-----------------------------------GPRS TXD
GND------------------------------GND
Hi, please can you help me with the arduino code for this example??? I've the same problem with this module.... I don't know how connect arduino uno with it.... please someone help me with the code... thanks
ollemagnusson:
So if I understand you correctly.GPRSTXD to Arduino D7
GPRSRXDto Arduino D8
GND to GND
GPRS VCC_MCU to Arduino 3,3VIn the code do:
gprsSerial.begin(115200); // GPRS shield baud rate
How do I set the following??
Data bits: 8
Stop bits: 1
Parity: None
Flow Control: None