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problem is sending sms with 8051 by siemens C55

hi friends. I am trying to send sms with 8051(89c51rc2)and siemens C55.But I failed.I dont know why.When I try to send sms,cellphone turns off. My sch

Re: problem is sending sms with 8051 by siemens C55

sendString("079109459208003311000C910945664173350000AA05E8329BFD06");//sms center no:+905429800033, destination number:+905466143753, message:"HELLO"

Re: problem is sending sms with 8051 by siemens C55

yes it is pdu mode.Because my cellphone is siemens C55 and it supports only pdu mode.I can send sms by hyperterminal with pdu mode.And I simulated it

Re: problem is sending sms with 8051 by siemens C55

my cellphone is siemens c55 and pin configuration is:http://pinouts.ru/CellularPhones-P-W/siemens_c55_pinout.shtmlwhere is DTR?

Re: problem is sending sms with 8051 by siemens C55

problem seems here..CODE:void checkOK()
{
for(j=0;j<2;j++)
rcvd[j]=rcv();
if(rcvd[

Re: problem is sending sms with 8051 by siemens C55

also you dont need to send all those commands...just try to send at+cmgs.and dont check OK.

Re: problem is sending sms with 8051 by siemens C55

I know.But I wanna check my pdu mode.So I have to know right communication.And my schematic is right?

Re: problem is sending sms with 8051 by siemens C55

in schematic......try with DTR pin of mobile = high

Re: problem is sending sms with 8051 by siemens C55

But I dont understand DTR pin of mobile=highhow it will be.It necessary.And how?

Re: problem is sending sms with 8051 by siemens C55

this schematic is right too?

Re: problem is sending sms with 8051 by siemens C55

do you know pin configuration of your mobile connector??you are not using datacable right?

Re: problem is sending sms with 8051 by siemens C55

I am not using data cable.And ı know siemens c55 pin configuration.

Re: problem is sending sms with 8051 by siemens C55

as you said u are connecting it to c55 directly then there is no need of DTR.. just direct connection with tx, rx and gnd.Did you try what i said? did

Re: problem is sending sms with 8051 by siemens C55

ok.I changed my program.You said me change 'O' and 'K' replaca 'o' and 'k'.I did but I havent tried yet.I will try soon.Thnks for everything

Re: problem is sending sms with 8051 by siemens C55

I do not see any pull up resistor in your schematic.The 8051 port pin can sink 1.6mA (3.2mA for port 0) and source 60uA.When used as outputs, all port

Re: problem is sending sms with 8051 by siemens C55

You have to buffer, or add a pull up resistor to P3.1.Also led design is wrong. 8051 family has open drain output stage with a weak pull up. The cellp

Re: problem is sending sms with 8051 by siemens C55

hi gioppy.I didnt understand you.You said "add a pull up resistor to P3.1"I have done already it.After that "led desing is wrong"how?8051 family has

Re: problem is sending sms with 8051 by siemens C55

did you test what i said?

Re: problem is sending sms with 8051 by siemens C55

thnks gioppy.Can you make a right schematic for my project .Please...

Re: problem is sending sms with 8051 by siemens C55

In your schematic just add a 10k resistor between Vcc and P3.1......that's your pullup.Like Gioppy suggested your LED's are sourcing current from the

Re: problem is sending sms with 8051 by siemens C55

ajay I have tried your suggestion.But I am failed.Cell phone doesnt give me anything.Where is my mistake plsease help me

Re: problem is sending sms with 8051 by siemens C55

I gave you two suggestions which one you tried?replacing ok with OK?try abbas's suggestion too.. no need to wait for OK.. just try sending AT commands

Re: problem is sending sms with 8051 by siemens C55

problem can be in micro-mobile connection.can't say more about it

Re: problem is sending sms with 8051 by siemens C55

my schematic and my codes are correct?

Re: problem is sending sms with 8051 by siemens C55

try to send only 1 command..like atd , tell about response you get

Re: problem is sending sms with 8051 by siemens C55

Have you tried with the external pullup?

Re: problem is sending sms with 8051 by siemens C55

edit your main for a while and replace it with thisCODE:void main()
{
P2_0=0;
&n

Re: problem is sending sms with 8051 by siemens C55

ajay I havent anytime to do it.Have you any projects that is finished about it.please help me.I have many class too.I havent more timesplease help m

Re: problem is sending sms with 8051 by siemens C55

just I will change my main function?and but in main functiom havent delay when transmitting at commands

Re: problem is sending sms with 8051 by siemens C55

I didnt understand external puul-up.I know just need when we use P0 port.we have to use external pull up.for P2 port doesnt need external pull up ,doe

Re: problem is sending sms with 8051 by siemens C55

yeah put delay after each at command.

Re: problem is sending sms with 8051 by siemens C55

you can put delay after this command CODE:
sendString("AT+CMGS=19");
sendChar(0x0D);

Re: problem is sending sms with 8051 by siemens C55

ok thnks friends.I have sent sms by 8051.I did it.My mistake is connection from 8051 to GSM.Thnks a lot....

Re: problem is sending sms with 8051 by siemens C55

good glad it worked...