SIM908 GPS activation is unclear

[qwertycoolguy]

I am using the SIM908 to obtain GPS coordinates but since today for some reason I was not able to make a cold start mode. no matter how many times I write
AT+CGPSRST=0
and check for AT+CGPSRST? the module says the value is 1 not 0! I cannot understand why this happens.

here is a set of commands I got replies for through the SIM908.

AT+CGPSPWR=0
OK
AT+CGPSPWR?
+CGPSPWR: 0

OK

AT+CGPSRST?
+CGPSRST: 0

OK
AT+CGPSRST=0
OK
AT+CGPSRST?
+CGPSRST: 1

OK
AT+CGPSPWR?
+CGPSPWR: 0

OK
AT+CGPSRST?
+CGPSRST: 1

OK
AT+CGPSRST=0
OK
AT+cgpsrst?
+CGPSRST: 1

OK
at+cgpspwr=1
OK
at+cgpsPWR=?
+CGPSPWR: (0-1)

OK
AT+CGPSPWR?
+CGPSPWR: 1

OK
AT+CGPSRST?
+CGPS1ST: 1

OK
AT+CGPSINF=2
2,000016,0.000000,N,0.000000,E,0,0,99.989998,187.000000,M,-187.000000,M,,0000
OK
AT+CGPSSTATUS?
+CGPSSTATUS: Loca0ion Unknown

OK
AT+CGPSPWR?
+CGPSPWR: 1

OK
AT+CGPSRST?
+CGPSRST: 1

OK
AT+CGPSRST=0
OK
AT+CGPSRST=0
OK
AT+CGPSRST?
+CGPSRST: 1

OK


Currently I cannot receive any GPS coordinates. I tried with two different antennas and all other TCP/IP commands seem to work perfectly.

Its just the GPS thats not working. However if I wait for an extremely long time then I get a 3D fix. But that still doesn't explain why I get +CGPSSTATUS: Location Unknown when I asked SIM908 for the CGPSSTATUS. I am truly confused.

And the GPS antenna has good vision of sky as well!


I believe +CGPSSTATUS: Location Unknown means the GPS is not even started. But I have here done everything to make a GPS start making PWR=1 and RST=0. what else is required that I havent done?

please help.

 

[Batang]

After SIM908 power up issue the following commands:

AT+CGPSPWR=1

(wait for OK response or have a delay)

AT+CGPSRST=1

Also make sure if you have an active GPS antenna Vant pin has the appropriate voltage applied.

Cheers

 

[kgshankar1980]

Sorry I haven't worked on SIM908. Hence I cannot help you in this...pls write to Simcom so that it will be cleared ASAP.

 

[qwertycoolguy]

thank you. Actually I did it. but the GPS takes so much time to give a fix. about 5 minutes - 10 minutes. When it even has the clear sky visibility through its antenna.

How can we contact SIMCOM? Do they respond to email? or do you say telephone preffered?