+ Post New Thread
Page 1 of 3 1 2 3 LastLast
Results 1 to 20 of 42
  1. #1
    Member level 3
    Points: 1,010, Level: 7
    behnam9856's Avatar
    Join Date
    Jan 2010
    Posts
    63
    Helped
    11 / 11
    Points
    1,010
    Level
    7

    Problem in module Sim908 - doesnt work

    Hi,

    when I turn on Sim908, It just send IIII???? and I dont receive anything more!

    also when I send AT commands, nothing happens!

    and Netlight LED shows that module is not registered in the network, 64ms on, 800ms off

    any one can help me plz...

    best regards

  2. #2
    Member level 3
    Points: 1,010, Level: 7
    behnam9856's Avatar
    Join Date
    Jan 2010
    Posts
    63
    Helped
    11 / 11
    Points
    1,010
    Level
    7

    Re: Problem in module Sim908 - doesnt work

    my problems in lat post solved.

    sim908 worked correctly and registered into network. but after a few minutes sim908 could not resister to network and i got this error: +CPIN: NOT READY

    and after a while i got this for one of our operators +CPIN: NOT INSERTED

    with another operator, first of all module send message to enter pin code and after it, some times i get +CPIN: NOT READY and error for AT+CPIN="XXXX"

    and sometimes it registers to the network and maybe i shows +CPIN: NOT READY after a while!

    anyone know why? plz reply... its urgent to solve this problem,

    best regards



    •   AltAdvertisment

        
       

  3. #3
    Banned
    Points: 3,760, Level: 14
    Achievements:
    7 years registered

    Join Date
    Feb 2010
    Location
    Muscat, Oman, Oman
    Posts
    388
    Helped
    64 / 64
    Points
    3,760
    Level
    14

    Re: Problem in module Sim908 - doesnt work

    can u share ur schematic . specially for the Power supply and simcard interface?

    if the powersupply cant provide the required power when the GSM module is transmitting , you can have such problems.

    Are u using 220nF cap at sim interface?



  4. #4
    Member level 3
    Points: 1,010, Level: 7
    behnam9856's Avatar
    Join Date
    Jan 2010
    Posts
    63
    Helped
    11 / 11
    Points
    1,010
    Level
    7

    Re: Problem in module Sim908 - doesnt work

    here's shematic.


    it worket correctly before!

    i checked voltage on sim vdd and i got that when the module is off, sim vdd is 0.87v and when module turns on, for one second it goes to 1.xx volts and then returns to 0.87 volts.

    but with another operator, some times the voltage is 3.x volt on sim vdd and after entering pin code, voltage is 2.x volts... but more times my voltage is on 0.87v

    ps: in the schematic as you see, sim card holder is 8 pins (2 pins are hide), but i used 6 pins in pcb



  5. #5
    Junior Member level 2
    Points: 2,194, Level: 10
    Achievements:
    7 years registered

    Join Date
    Jun 2007
    Posts
    22
    Helped
    1 / 1
    Points
    2,194
    Level
    10

    Re: Problem in module Sim908 - doesnt work

    A 78M05?????? Didn't you read the SIM908 datasheet?



  6. #6
    Member level 3
    Points: 1,010, Level: 7
    behnam9856's Avatar
    Join Date
    Jan 2010
    Posts
    63
    Helped
    11 / 11
    Points
    1,010
    Level
    7

    Re: Problem in module Sim908 - doesnt work

    yes, but i used 7805cv in pcb and it works!

    I have a sim900 and the regulator's 7805cv... works pretty good!
    Last edited by behnam9856; 4th May 2012 at 22:34.



  7. #7
    Member level 3
    Points: 1,010, Level: 7
    behnam9856's Avatar
    Join Date
    Jan 2010
    Posts
    63
    Helped
    11 / 11
    Points
    1,010
    Level
    7

    Re: Problem in module Sim908 - doesnt work

    no any idea?



  8. #8
    Member level 3
    Points: 1,010, Level: 7
    behnam9856's Avatar
    Join Date
    Jan 2010
    Posts
    63
    Helped
    11 / 11
    Points
    1,010
    Level
    7

    Re: Problem in module Sim908 - doesnt work

    All right... Solved!



    •   AltAdvertisment

        
       

  9. #9
    Banned
    Points: 3,760, Level: 14
    Achievements:
    7 years registered

    Join Date
    Feb 2010
    Location
    Muscat, Oman, Oman
    Posts
    388
    Helped
    64 / 64
    Points
    3,760
    Level
    14

    Re: Problem in module Sim908 - doesnt work

    what was the problem and how you solved that?



    •   AltAdvertisment

        
       

  10. #10
    Newbie level 4
    Points: 1,128, Level: 7

    Join Date
    Jun 2008
    Posts
    5
    Helped
    0 / 0
    Points
    1,128
    Level
    7

    Re: Problem in module Sim908 - doesnt work

    Can you please tell me the solution as I am also facing problem with SIM908.Its not generating SIMVDD. WHen module powers ON,it generates SIM VDD for few milliseconds and then goes to zero.

    I am using LM350 for SIM module supply.

    Its urgent.Please reply.

    Thanks,
    AMit


    Quote Originally Posted by behnam9856 View Post
    All right... Solved!



  11. #11
    Member level 3
    Points: 1,010, Level: 7
    behnam9856's Avatar
    Join Date
    Jan 2010
    Posts
    63
    Helped
    11 / 11
    Points
    1,010
    Level
    7

    Re: Problem in module Sim908 - doesnt work

    allright, my problem was because of GND wire and noise on the circuit!

    i designed another PCB with wide GND wire, alsi i used polygon under sim908 and around it...

    i used LM75CV and a 1n4007 for power...

    here's my pcb in altium designer 9.4

    http://www.4shared.com/file/_8jtFaHX/Sim908.html

    hope to help u...

    P.S, try to use MAX3232 instead of MAX232 if u're using COM port.


    1 members found this post helpful.

  12. #12
    Newbie level 4
    Points: 1,128, Level: 7

    Join Date
    Jun 2008
    Posts
    5
    Helped
    0 / 0
    Points
    1,128
    Level
    7

    Re: Problem in module Sim908 - doesnt work

    Thanks a lot for your reply.
    I will try these changes.

    regards,
    Amit

    Quote Originally Posted by behnam9856 View Post
    allright, my problem was because of GND wire and noise on the circuit!

    i designed another PCB with wide GND wire, alsi i used polygon under sim908 and around it...

    i used LM75CV and a 1n4007 for power...

    here's my pcb in altium designer 9.4

    http://www.4shared.com/file/_8jtFaHX/Sim908.html

    hope to help u...

    P.S, try to use MAX3232 instead of MAX232 if u're using COM port.



  13. #13
    Newbie level 4
    Points: 84, Level: 1

    Join Date
    Aug 2012
    Posts
    6
    Helped
    1 / 1
    Points
    84
    Level
    1

    Re: Problem in module Sim908 - doesnt work

    Hi, I am vipintruder ;P

    behnam9856: Could you tell me how you solve the problem with IIII menssage please?

    When I turn on Sim908, It just send IIII... and I dont receive anything more.

    Best regards.



  14. #14
    Member level 3
    Points: 1,633, Level: 9
    Achievements:
    7 years registered
    kvtal's Avatar
    Join Date
    Sep 2009
    Location
    india
    Posts
    64
    Helped
    5 / 5
    Points
    1,633
    Level
    9

    Re: Problem in module Sim908 - doesnt work

    can u plese repost ur schematic im also trying a circuit with sim908
    vital kantamneni



  15. #15
    Member level 3
    Points: 1,010, Level: 7
    behnam9856's Avatar
    Join Date
    Jan 2010
    Posts
    63
    Helped
    11 / 11
    Points
    1,010
    Level
    7

    Re: Problem in module Sim908 - doesnt work

    Quote Originally Posted by vipintruder View Post
    Hi, I am vipintruder ;P

    behnam9856: Could you tell me how you solve the problem with IIII menssage please?

    When I turn on Sim908, It just send IIII... and I dont receive anything more.

    Best regards.
    is your module baud rate automatic? set a baud rate for module like 9600

    Quote Originally Posted by kvtal View Post
    can u plese repost ur schematic im also trying a circuit with sim908
    here's the schematic: http://www.novinupload.com/uploads/13452712681.png



  16. #16
    Newbie level 4
    Points: 84, Level: 1

    Join Date
    Aug 2012
    Posts
    6
    Helped
    1 / 1
    Points
    84
    Level
    1

    Re: Problem in module Sim908 - doesnt work

    How can I set a baud rate for module like 9600?, because I can't send any AT command.

    I have connected the module to my PC by RS-232 (with RS232-TTL conversor). I recived the IIII message only when I configure the software (GtkTerm - "like hyperterminal in Windows") with 115200 bauds, but I can't write any command in it.

    Thank you for your response and your help.

    Best regards.


    1 members found this post helpful.

    •   AltAdvertisment

        
       

  17. #17
    Junior Member level 2
    Points: 2,194, Level: 10
    Achievements:
    7 years registered

    Join Date
    Jun 2007
    Posts
    22
    Helped
    1 / 1
    Points
    2,194
    Level
    10

    Re: Problem in module Sim908 - doesnt work

    You can and you must write, according to the datasheet. Read it.



  18. #18
    Member level 3
    Points: 1,633, Level: 9
    Achievements:
    7 years registered
    kvtal's Avatar
    Join Date
    Sep 2009
    Location
    india
    Posts
    64
    Helped
    5 / 5
    Points
    1,633
    Level
    9

    Re: Problem in module Sim908 - doesnt work

    than q very much for ur schematic
    which microcontroller u used for ur aplication
    vital kantamneni



  19. #19
    Member level 3
    Points: 1,010, Level: 7
    behnam9856's Avatar
    Join Date
    Jan 2010
    Posts
    63
    Helped
    11 / 11
    Points
    1,010
    Level
    7

    Re: Problem in module Sim908 - doesnt work

    Quote Originally Posted by kvtal View Post
    than q very much for ur schematic
    which microcontroller u used for ur aplication
    than q? what u mean?

    I used Avr family, ATmega128.

    p.s, use MAX3232 instead of max232...



  20. #20
    Member level 3
    Points: 1,633, Level: 9
    Achievements:
    7 years registered
    kvtal's Avatar
    Join Date
    Sep 2009
    Location
    india
    Posts
    64
    Helped
    5 / 5
    Points
    1,633
    Level
    9

    Re: Problem in module Sim908 - doesnt work

    sorry its thanx
    vital kantamneni



--[[ ]]--