Hi all,
I am using module sim908 in my project.
I want to know whether I use the same module UART of MCU for both GMS and GPS module of sim908.
Now, GSM module work well (can send/read sms, make voice call ...).
But I send "AT+CGPSPWR=1" to power up GPS then the modem do not respond anything.
Thank you!
Hi. I solved this problem. Now I use GSM and GPS with only one module UART.
I faced another 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,0.00,0.00,101010,,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??
Thank you
I have an application to use this module sim908 in a forest. far away from city but sky is clearly seen. Would the module function?
Sure, dear!
jurst to be sure.. given a clear sky, can a gps track location of any country in the world? I live in SL, so anywhere!! literally! be tracked?
also with regard to SIM908, is it bad to switch on the SIM908 module without connecting antenas? would it damage the module?
Hi, SIM908 need antenna to fix the location.
hi Amalinda,
yes, it is possible to use GPS literally anywhere in the world with GPS given that the module is receiving proper signals...
I've tried several GPS modules in many places around Sri Lanka, which were bought from ebay.
GPS satellites have covered the whole world!
Without the antenna, the RF power generated by the module reflects back to the source. Just think about an open ended transmission line.
Depending on the length of the transmission line, the built up voltage levels at the source varies. So, there's a probability of damaging your module.
Generally, it's a good idea (i would say a rule of thumb) to connect a proper antenna for any kind of RF transmitter/transceiver before turning it on.
If there's only a receiver, there's no chance to damage the device without an antenna since it's not transmitting RF signals.
Since SIM908 is a transceiver, always good to have an antenna connected before power it up...
Hi. I solved this problem. Now I use GSM and GPS with only one module UART.
I faced another 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,0.00,0.00,101010,,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??
Thank you
Hi. I solved this problem. Now I use GSM and GPS with only one module UART.
I faced another 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,0.00,0.00,101010,,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??
Thank you
Hi ThiVu
In my project is using sim908. Are You send comand AT for GPS via pins 68 and 71 (68:GsmRXD 71:GsmTXD ) ?
if I have to use both UART of sim908 need a MCU with 2 UART
thank you
-------------------------------------------------------------------------------------
- - - Updated - - -
Hi ThiVu
In my project is using sim908. Are You send comand AT for GPS via pins 68 and 71 (68:GsmRXD 71:GsmTXD ) ?
if I have to use both UART of sim908 need a MCU with 2 UART
thank you
-------------------------------------------------------------------------------------
GPRS_cmd("AT+CGPSPWR=1\r\n");
delay_ms(5000);
GPRS_cmd("AT+CGPSRST=0\r\n");
delay_ms(1000);
GPRS_cmd("AT+CPSRST?\r\n");
delay_ms(500);
GPRS_cmd("AT+CGPSINF=0\r\n");
delay_ms(2500);
GPRS_cmd("AT+CGPSSTATUS?\r\n");
delay_ms(500);
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?