Pic18F4550 + SIMCOM SIM900D GSM/GPRS

[tacbanon]

Check does it send correctly with HT. Use your usb ttl uart converter board.
Try to send CRLF then pause 100, and then send command...

On the SERIAL COMMUNICATORl, sending AT commands had no problems( w/ CR and CRLF).


Regards,
tacbanon

[tacbanon]

I tried other serial communicator, and I'm not sure if I found the trouble...

When I disable the Append New Line


With New line after sending

Do you think adding new line after each send will solve it - how?

HSEROUT ["AT",13] 
HSERIN 4000, GSM_CHECK_ERR, [WAIT("OK")]

The code above does not detect "OK".

regards,
tacbanon

[pedja089]

Try to connect PC to PIC, instead of modem...
Also use Rx on PC board to sniff what is happening when pic and modem communicate...

[tacbanon]

I tried to modify my hardware setup to detect whats going IN and OUT in the GSM module (below). I test each button(Button1-Button3) and each corresponding response of the GSM shown in the serial communicator.


I noticed that everything seems normal..but when I tried the connection PIC-GSM... I have the same issue.
So sending PIC to GSM AT commands is not issue..I think when receiving incoming data from GSM to PIC is where the trouble is.

Regards,
tacbanon

[tacbanon]

I noticed that everything seems normal..but when I tried the connection PIC-GSM... I have the same issue.

What I meant was, when I set the entire connection between PIC-GSM I have the trouble again(need to press the reset button on my Labx2 devboard)

[tacbanon]

For testing I removed all HSERIN command to see if it will continue each line. And below is the results.

Here is the code I'm using...

 asm
    __CONFIG    _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & _USBDIV_2_1L
    __CONFIG    _CONFIG1H, _FOSC_HSPLL_HS_1H & _FCMEN_OFF_1H & _IESO_OFF_1H
    __CONFIG    _CONFIG2L, _PWRT_ON_2L & _BOR_ON_2L  & _BORV_2_2L  & _VREGEN_ON_2L   
    __CONFIG    _CONFIG2H, _WDT_OFF_2H 
    __CONFIG    _CONFIG3H, _MCLRE_ON_3H & _LPT1OSC_OFF_3H & _PBADEN_OFF_3H & _CCP2MX_ON_3H 
    __CONFIG    _CONFIG4L, _STVREN_ON_4L & _LVP_OFF_4L & _ICPRT_OFF_4L  & _XINST_OFF_4L & _DEBUG_OFF_4L 
endasm

        
        DEFINE OSC 48
  

        DEFINE HSER_RCSTA 90h ' enable serial port, 
        DEFINE HSER_TXSTA 20h  ' enable transmit, * we change 20h to 36 for 115200          
        DEFINE HSER_BAUD 9600
        DEFINE HSER_CLOERR  1 ' automatic clear overrun error  
        
        TRISC  = %10000000    ' PORTC.7 is the RX input, PORTC.6 is the TX output
                              
    
    '   Serial communication definition
    '   ===============================
        '
ADCON1 = %00001111      'Set up ADCON1 register no matter what you're doing!!!!!!
'::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::

INCLUDE "MODEDEFS.BAS"       ' Include Shiftin/out modes


'*****************************************************************************     


INTCON2.7 = 0        ' Enable PORTB pull-ups

TRISB = %11111000
TRISC = %10000000
led1 var PortC.0
cntr var byte
cntr = 0
TRISD = %00000000

 
Serout2 PORTD.5, 84, [$1B,$63,$30]  
Serout2 PORTD.5, 84, [$1B,$45, "Start GSM SIMU"]   ' Serial LCD
main:

PAUSE 1000
HSEROUT ["AT",13,10]                    'Send AT to modem followed by a CR
pause 200
cntr=cntr+1
Serout2 PORTD.5, 84, [$1B,$45,"Start GSM SIMU"]
Serout2 PORTD.5, 84, [$D,"AT -Done",#cntr]
cntr=cntr+1

pause 1000
HSEROUT["AT+CMGF=1",13]             'Here the GSM module is being entered in TEXT MODE.
PAUSE 1000
HSEROUT ["AT+CSQ",13,10]                    
pause 200
Serout2 PORTD.5, 84, [$1B,$45,"Start GSM SIMU"]
Serout2 PORTD.5, 84, [$D, "SIGNAL CHK",#cntr]


PAUSE 1000
HSEROUT ["AT+CGMI",13,10]                           'Ask model name
pause 200
cntr=cntr+1
Serout2 PORTD.5, 84, [$1B,$45,"Start GSM SIMU"]
Serout2 PORTD.5, 84, [$D, "MANUFACT CHK",#cntr]

Pause 1000
Serout2 PORTD.5, 84, [$1B,$45,"Start GSM SIMU"]
Serout2 PORTD.5, 84, [$D,"GSM TEST DONE!",#cntr]

End     ' End of program

Can anyone pin point what I'm doing wrong in my code..and why HSERIN is not detecting data coming out from GSM?
I Appreciate any help.

Thanks in advance,
tacbanon

[pedja089]

Maybe problem is in supply voltage. Modem works on 2.8V(it have internal regulator), so pic should work on 3.3V, and you must have serial resistor on pic TX. So modem can't draw any current from pic TX pin.