GPS Tracker using SIM908

[vikasmaan]

Hello everyone,
I am working on a project of GPS tracker and I decided to use SIM908 which is a GSM/GPS/GPRS combo module having complete support of AT commands to control all functionalities. So I am planning to use microcontroller like 8051 with this module.
My only target with this project is to send gps location thru gsm and gprs when it will get a sms request for location. Otherwise
this device will be in sleep mode.

What I found is, this combo module has 1mA current requirements under sleep mode. So if we use a 960mAh Li-Ion battery with this product, then how many days it can stay with this battery?

One more thing please tell me if anyone already used this module for GPS tracker project, how much cost could occur for all this whole assembly including SIM908, microcontroller, any boards, and battery or if any other thing required.

I am kind of newbie for electronics project so please dont mind if my assumptions are wrong.

thanks

 

[anothermort]

So you know the sleep mode requirements of 1mA.
But what does it use when it is not in sleep mode and how often are you going to wake it up to use it.

As it will last a long time in sleep mode on that battery (approx 960 hours), but you need the other variables to find out its true runtime.
Is this battery also powering other functions i.e. a controlling micro

Hope that helps a bit.

 

[vikasmaan]

thanks anothermort for your reply.
You are correct. other modules will also be consuming the same battery. But I want all modules in full sleep mode except this
SIM908. SIM908 will be in some deep sleep mode and polling every 10 minutes for some new messages. I am not sure but deep sleep mode should be kind of where not battery should be consumed. So every 10 minute this module will wake up and check for SMS and if no SMS it will deep sleep again. So if this is the only requirement then how long this much capacity battery can run?

Please help me in find out the price also. which cheapest uC i should use and i tried SIM908 cost in market, it is around $27.

thanks in advance.

So you know the sleep mode requirements of 1mA.
But what does it use when it is not in sleep mode and how often are you going to wake it up to use it.

As it will last a long time in sleep mode on that battery (approx 960 hours), but you need the other variables to find out its true runtime.
Is this battery also powering other functions i.e. a controlling micro

Hope that helps a bit.

 

[anothermort]

So are you saying the 1ma is what the unit uses when it wakes up to check for sms every ten minutes?
Sorry just want to make sure I understand.
If so what does it use in deep sleep?


Have not used the SIM908, but any micro with a uart will do if you are just receiving the sms.
But best to ask someone with more knowledge of the SIM908.

 

[p.mansournia]

hi
I have problems in GPS run ( GPS data is not correct ....
What should I do?

 

[vikasmaan]

hi
I have problems in GPS run ( GPS data is not correct ....
What should I do?

We are also using SIM908c module for our project. But we are facing issue in sim network registration. After module power on sim network registration is failing every time. After power on module it returns "NORMAL POWER DOWN +CREG:3 +CGREG:3". Did you also face this issue ?

 

[chackad]

We are also using SIM908c module for our project. But we are facing issue in sim network registration. After module power on sim network registration is failing every time. After power on module it returns "NORMAL POWER DOWN +CREG:3 +CGREG:3". Did you also face this issue ?

is there any body that run gps sim908 ?
i need some data shuch as pdf file that describe How run GPS of Sim908 .
thanks.

 

[vuln3r]

We are also using SIM908c module for our project. But we are facing issue in sim network registration. After module power on sim network registration is failing every time. After power on module it returns "NORMAL POWER DOWN +CREG:3 +CGREG:3". Did you also face this issue ?

Dear vikasmaan,,
it seems like there's a power supply failure,,, please check your VBAT is in the recommended voltage range according to the datasheet (about 3.5V to 4.8V)

that much i can give right now... success to your project..

 

[vishwanath03]

Hi frds

We also planning to work on same project and we also select sim908, but i don't have any review of this chip, having some questions regarding its performance and connectivity. Is any body used this in field and wht you put in its review.

Thanks

 

[ayyoob]

i run sim908 too
but cant access to GPS and its status is unknown location
what to do?
plz!!

 

[ayyoob]

We are also using SIM908c module for our project. But we are facing issue in sim network registration. After module power on sim network registration is failing every time. After power on module it returns "NORMAL POWER DOWN +CREG:3 +CGREG:3". Did you also face this issue ?

hi vikasmaan
I work with sim908 too
I power on it and the module find and register to GSM net and some works like sending SMS.
but it can not find gps location properly and it status is "Location Unknown"
can you help me what to do?:???:

 

[eng.ahmed]

Hello Guys,
Actually are you using a Passive GPS Antenna or Active GPS Antenna, if Active one so don't forget to make sure that you're supplying the GPSANT pin with the antenna propper voltage!
Command procedure which worked with me after contacting the Technical Support:

// Memorizing GPS configurations' commands into Code Memory
char strGPS_PowerUp		[] PROGMEM = "AT+CGPSPWR=1\r\n";
char strGPS_Mode1		[] PROGMEM = "AT+CGPSRST=1\r\n";
char strGPS_BaudRate	[] PROGMEM = "AT+CGPSIPR=9600\r\n";
char strGPS_OutPut		[] PROGMEM = "AT+CGPSOUT=32\r\n";
char strGPS_PowerDown	[] PROGMEM = "AT+CGPSPWR=0\r\n";

 

[ThiVu]

hi vikasmaan
I work with sim908 too
I power on it and the module find and register to GSM net and some works like sending SMS.
but it can not find gps location properly and it status is "Location Unknown"
can you help me what to do?:???:

Hello Guys,
Actually are you using a Passive GPS Antenna or Active GPS Antenna, if Active one so don't forget to make sure that you're supplying the GPSANT pin with the antenna propper voltage!
Command procedure which worked with me after contacting the Technical Support:

// Memorizing GPS configurations' commands into Code Memory
char strGPS_PowerUp		[] PROGMEM = "AT+CGPSPWR=1\r\n";
char strGPS_Mode1		[] PROGMEM = "AT+CGPSRST=1\r\n";
char strGPS_BaudRate	[] PROGMEM = "AT+CGPSIPR=9600\r\n";
char strGPS_OutPut		[] PROGMEM = "AT+CGPSOUT=32\r\n";
char strGPS_PowerDown	[] PROGMEM = "AT+CGPSPWR=0\r\n";

I am also facing with this problem.
This is my command sequence:

send:AT

recv: 6

OK


send:AT+CSQ

recv: 20

+CSQ: 22,0



OK


send:AT+GSV

recv: 65

SIMCOM_Ltd

SIMCOM_SIM908

Revision:1137B03SIM908M64_ST



OK



send:AT+CGPSPWR=1

recv: 6

OK


send:AT+CGPSRST=0

recv: 6

OK


send:AT+CGPSOUT=255

recv: 6

OK


send:AT+CGPSIPR=115200

recv: 6

OK


send:AT+CGPSSTATUS?

recv: 39

+CGPSSTATUS: Location Unknown



OK


send:AT+CGPSINF=32

recv: 67

32,000054.001,V,0.000000,N,0.000000,E,0.00,0.00,10 1010,,E,A

OK

---------------
I received respond form CGPSSTATUS: Location Unknown
And data from CGPSINF seem to be invalid.
Could you help me to solve this.
Maybe I make mistake or forgot some command??
My GPS antenna is placed outside so I dont think the problem come from antenna.
Thank you

 

[Echo wang]

I am also facing with this problem.
This is my command sequence:

send:AT

recv: 6

OK


send:AT+CSQ

recv: 20

+CSQ: 22,0



OK


send:AT+GSV

recv: 65

SIMCOM_Ltd

SIMCOM_SIM908

Revision:1137B03SIM908M64_ST



OK



send:AT+CGPSPWR=1

recv: 6

OK


send:AT+CGPSRST=0

recv: 6

OK


send:AT+CGPSOUT=255

recv: 6

OK


send:AT+CGPSIPR=115200

recv: 6

OK


send:AT+CGPSSTATUS?

recv: 39

+CGPSSTATUS: Location Unknown



OK


send:AT+CGPSINF=32

recv: 67

32,000054.001,V,0.000000,N,0.000000,E,0.00,0.00,10 1010,,E,A

OK

---------------
I received respond form CGPSSTATUS: Location Unknown
And data from CGPSINF seem to be invalid.
Could you help me to solve this.
Maybe I make mistake or forgot some command??
My GPS antenna is placed outside so I dont think the problem come from antenna.
Thank you

Pls test your antenna operating voltage! Do it meet the requesting?

---------- Post added at 12:55 ---------- Previous post was at 12:51 ----------

hi vikasmaan
I work with sim908 too
I power on it and the module find and register to GSM net and some works like sending SMS.
but it can not find gps location properly and it status is "Location Unknown"
can you help me what to do?:???:

Hi, guy, same as Thivu, Pls test your antenna's operating voltage.
There are 2 pin supply the power to the antenna. Pls connect pin 75 and 76

---------- Post added at 13:04 ---------- Previous post was at 12:55 ----------

is there any body that run gps sim908 ?
i need some data shuch as pdf file that describe How run GPS of Sim908 .
thanks.

Pls offer your e-mail address

---------- Post added at 13:07 ---------- Previous post was at 13:04 ----------

We are also using SIM908c module for our project. But we are facing issue in sim network registration. After module power on sim network registration is failing every time. After power on module it returns "NORMAL POWER DOWN +CREG:3 +CGREG:3". Did you also face this issue ?

Pls check whether your AT command has keyed in "AT+CPOWD=1"?
If no, pls check PWRKEY.

 

[Echo wang]

hi
I have problems in GPS run ( GPS data is not correct ....
What should I do?

Could you offer detail information?

 

[Ichan]

Hi Echo wang,

Looks like you know much about SIM908.

I am struggling for several days now where the gps coordinate given by my SIM908 very much not accurate, it shows my home missed about 20km on google maps!

What could be the cause? I use 3-5V ceramic patch antenna with GPS-VANT-IN pin connected to VBAT (4.2V) and GPS-VANT-OUT left open, antenna connected through GPS RF connector.

TIA, Ichan.

 

[Echo wang]

Hi Echo wang,

Looks like you know much about SIM908.

I am struggling for several days now where the gps coordinate given by my SIM908 very much not accurate, it shows my home missed about 20km on google maps!

What could be the cause? I use 3-5V ceramic patch antenna with GPS-VANT-IN pin connected to VBAT (4.2V) and GPS-VANT-OUT left open, antenna connected through GPS RF connector.

TIA, Ichan.

Hi, dear Ican, pls kindly check the module version with "AT+CGMR" at first, pls send the version information to me.

 

[Ichan]

Hi Echo Wang, thanks for your respond.

The problem solved, my bad to miss interpret the output of AT+CGPSINF=0 command - here is my answer of my own similar question on other forum https://www.sonsivri.to/forum/index.php?topic=44973

The AT+CGMR command give me Revision:1137B03SIM908M64_ST, is there newer firmware available?

I have a feeling that you are one of Simcom FAE , how to get the tools for SIM908 EAT?

-ichan

 

[ThiVu]

Thank to all,
I have connected GPS-VANT-IN to 3,3V and my problem is solved.

 

[Echo wang]

Hi Echo Wang, thanks for your respond.

The problem solved, my bad to miss interpret the output of AT+CGPSINF=0 command - here is my answer of my own similar question on other forum https://www.sonsivri.to/forum/index.php?topic=44973

The AT+CGMR command give me Revision:1137B03SIM908M64_ST, is there newer firmware available?

I have a feeling that you are one of Simcom FAE , how to get the tools for SIM908 EAT?

-ichan

Hi, Ichan,
:razz: I am not SIMCOM FAE, but I have focus on SIMCOM module for 5years.
Your version B03 is the updated one.
I have SIM908 EAT, how could I send to you?