I have to make this project for my school but i can't make it run. I've problems with message extraction and with the interrupt. Please help. This is my code
#include <reg51.h> #include <string.h> sbit Water=P2^0; sbit Window=P2^1; //declarations void clear(void); void tx0(unsigned char); void delay_sms (unsigned int); void SMSString(char*text) ; void init(); void read_text(unsigned char * , unsigned char * , unsigned char *); unsigned char j,abc; unsigned char idata msg1[150]; unsigned char rec_no[20]; unsigned char time_date[20]; unsigned char choice=0; unsigned char idata tmp10[16]; void serial () interrupt 4 { msg1[abc]=SBUF; abc++; RI=0; } void main (void) { clear(); init(); Window=0; Water=0; SMSString("AT\r"); // AT commands to initialize gsm modem delay_sms(1000); SMSString( "ATe0\r"); // turn off echo delay_sms(1000); SMSString( "AT&W\r"); // save settings delay_sms(1000); SMSString( "AT+CMGF=1\r"); // select text mode for sms delay_sms(1000); SMSString( "AT+CNMI=2,1,0,0,0\r"); // notification of new sms delay_sms(1000); SMSString( "AT+CMGR=1\r"); // AT command to read sms delay_sms(1000); do { IE=0X90; // Enable serial interrupt delay_sms(1000); // i get a response like this // +CMGR: "REC UNREAD","+3069********",,"11/04/09,11:26:48+12" // Window on // OK // I think that's the format the 8051 get +CMTI: "SM",1\r+CMGR: "REC UNREAD","+306982037789",,"11/04/09,11:26:48+12"\rStatus\n\rOK\r // read sms and store in buffer msg1 read_text(msg1,rec_no,time_date); if(strncmp("Water on",msg1,8)==0) { Water=1; strncpy(tmp10,"Water Window ",16); tmp10[6]=Water; tmp10[15]=Window; SMSString("AT+CMGS=\""); SMSString(rec_no); SMSString("\"+<CR>"); delay_sms(1000); SMSString(tmp10); SMSString("\n\r"); delay_sms(1000); } else if(strncmp("Water off",msg1,9)==0) { Water=0; strncpy(tmp10,"Water Window ",16); tmp10[6]=Water; tmp10[15]=Window; SMSString("AT+CMGS=\""); SMSString(rec_no); SMSString("\"+<CR>"); delay_sms(1000); SMSString(tmp10); SMSString("\n\r"); delay_sms(1000); } else if(strncmp("Window on",msg1,9)==0) { Window=1; strncpy(tmp10,"Water Window ",16); tmp10[6]=Water; tmp10[15]=Window; SMSString("AT+CMGS=\""); SMSString(rec_no); SMSString("\"+<CR>"); delay_sms(1000); SMSString(tmp10); SMSString("\n\r"); delay_sms(1000); } else if(strncmp("Window off",msg1,10)==0) { Window=0; strncpy(tmp10,"Water Window ",16); tmp10[6]=Water; tmp10[15]=Window; SMSString("AT+CMGS=\""); SMSString(rec_no); SMSString("\"+<CR>"); delay_sms(1000); SMSString(tmp10); SMSString("\n\r"); delay_sms(1000); } else if(strncmp("Status",msg1,6)==0) { strncpy(tmp10,"Water Window ",16); tmp10[6]=Water; tmp10[15]=Window; SMSString("AT+CMGS=\""); SMSString(rec_no); SMSString("\"+<CR>"); delay_sms(1000); SMSString(tmp10); SMSString("\n\r"); delay_sms(1000); } else { SMSString("AT+CMGS=\""); SMSString(rec_no); SMSString("\"+<CR>\r"); delay_sms(1000); SMSString("Wrong Command"); SMSString("\n\r"); delay_sms(1000); SMSString(rec_no); delay_sms(1000); SMSString(msg1); delay_sms(1000); } SMSString("AT+CMGD=1\r"); delay_sms(1000); IE=0X00; // Disable serial interrupt delay_sms(1000); } while(1); } void init(void) { j=0; abc=0; TL1=0XFD; //9600 @ 11.0592 TH1=0xFD; TMOD=0x20; SCON=0x50; TR1=1; } void SMSString(unsigned char* text) //function to send SMS using GSM modem { while (*text) { tx0(*text++); } } void tx0(unsigned char x) //send data to serial port 0 { EA=0; SBUF=x; while(TI==0); TI=0; EA=1; } void delay_sms (unsigned int count) { unsigned int i; while(count) { i = 115; while(i>0) i--; count--; } } void read_text( unsigned char *msg,unsigned char *no ,unsigned char *time) { unsigned char *temp; temp=msg; do msg++; while(*msg!='+'); do msg++; while(*msg!='+'); do msg++; while(*msg!='+'); // reaching number do *no++=*msg++; while(*msg!='"'); // reaching time *no++='\0'; msg++; msg++; msg++; do *time++=*msg++; while(*msg!='"'); // reaching message *time='\0'; do msg++; while(*msg!='\r'); msg++; do *temp++=*msg++; while(*msg!='\n'); // reaching the end of message *temp='\0'; } void clear(void) { unsigned char a; for(a=0;a<100;a++) msg1[a]=0x00; }
Note that debugging is an inherent part of the development process.
It is time for you to start debugging what you've written.
Here are some debugging tips & techniques:
www.8052.com/.../120313
www.techonlineindia.com/.../Developing_a_good_bedside_manner.aspx
You haven't mentioned what specific processor you are using.
If your processor doesn't have on-chip debug, then the easiest way to debug it is to run it in the Simulator, redirect the UART IO to the COM port, and connect your GSM modem to the COM port.
http://www.keil.com/support/man/docs/uv4/uv4_db_dbg_serialwin.htm
See comments here about arbitrary delays: http://www.keil.com/forum/18684/ See also: http://www.keil.com/forum/18696/
See comments here about delay loops in 'C': www.8052.com/.../181806 www.8052.com/.../181789
Your code would be easier to read, maintain, and debug with proper indentation, meaningful names (not "abc" and magic numbers), and a good deal more descriptive comments.
void serial () interrupt 4 { msg1[abc]=SBUF; abc++; RI=0; }
abc being a meaningful name "advanced buffer counter" or what?
It most definitely seems to be the insert position in your receive buffer for serial data. So why name it something like that?
And msg1 seems to be your receive buffer for serial data, so why not name it something like that?
You have msg1 defined as 150 characters large - your interrupt handler doesn't check where you are. What happens if you receive 151 characters? Would that be good?
You initialize abc to zero. But how do you get your receive interrupt to reuse msg1 for receiving data after you have processed some received data?
strncpy(tmp10,"Water Window ",16); tmp10[6]=Water; tmp10[15]=Window;
You are mixing ASCII and binary data in the same string. Do you think that is good? What about instead doing sprintf() to create a fully ASCII string with the values of "Water" and "Window" inserted?
Your read_text() function is more or less a random noise.
Don't you think you should process your answers line-by-line, and then look at the start of each received line to figure out what command you are decoding? Then it would be much better to split the parameters on the commas (while remembering that a comman can exist within a "" string too) when trying to locate the time and message.
SMSString("AT+CMGS=\""); SMSString(rec_no); SMSString("\"+<CR>");
On one hand - don't you think some things deserves to be a specific function, that does know to send a command and also does know to check for expected - or unexpected - answers? And what is "<CR>"?
What is delay_sms(1000)? Wouldn't it be better to implement a delay function that has a known property like creating delays in ms resolution, and then do delay_ms(POWER_ON_SETTLE_TIME) or similar? In your case, you have zero documentation what delay_sms() does that makes it meaningful to be called or to have "sms" as part of the name.
And why do you have so many hard-coded delays? Don't you think you should be more dynamic - send an SMS command and then listen for the characters being received from the modem on the fly? All you need is a timeout value when to give up. But if you get the answer much faster, then you don't have any reason to continue waiting. After all - how do you know what is a reasonable time to wait? Will that wait time always be true? Even with another operator or with overloaded network or with bad signal strength?
Especially considering that the maximum length of an SMS is - what?
In processors with limited memory, you normally don't have large buffers for storing worst-case multiline data. The normal way to handle things is to have a state machine that processers received characters on-the-fly (either directly from the serial port but often using a smaller ring-buffer to reduce the tight time coupling between serial port and processing).
The state machine can then figure out what is the start of a new text line, what is echo, what is answer, etc. And when processing answers, it can on-the-fly decode the individual fields in the answer to extract time, message etc. And such state machines can also take care of any unexpected unsolicited messages you may receive from a modem, such as a ring message if someone happens to ring the subscriber number while you think you are about to check for reception of an SMS - the modem promises that any unsolicited messages will not be inlined inside other text l ines so it's trivial for a state machine to handle them while handling all other answers.
So you can constantly check if your state machine have found something interesting you want to handle - like an unsolicited message that the modem has an overtemperature or other interesting messages it may be capable to report. And you can send commands to the modem and within a timeout interval check that you get expected responses - any enabled echo strings, ok/error strings, any specific answer string. When you have received what you should recieve or an error message, you can then figure out what to do next, i.e. if you have more strings to send to the modem.
Yes, State Machines are ideal for this kind of problem!
The use of State Machines is mentioned in one of the threads previously linked: http://www.keil.com/forum/18696/
First of all i want to thank you for you time. I have an Philips 89C51RD+. The delay_sms() creates a delay in ms, e.x. delay_sms(1000) creates 1sec delay. I'll try to fix the things you recommended but i really don't understand state machines. I'll sent you the new code when i done it.
As the linked article says, you really need to learn about State Machines!
en.wikibooks.org/.../Modems_and_AT_Commands
They are an (almost) essential tool in this type of problem, and an invaluable tool in many other types of problem.
Time invested now in learning about State Machines will reap bountiful rewards in the future...
Here's a simple tutorial: www.8052.com/.../47505
Only under a very limited set of circumstances - some of which you haven't specified, and some of which are not within your control as a 'C' programmer!!
See: www.8052.com/.../162556
The delay_sms() creates a delay in ms, e.x. delay_sms(1000) creates 1sec delay. maybe today, maybe tomorrow, maybe not next week
NOBODY knows what a compiler will do to a delay routine, delays MUST be done in assemble or with timers
Also, why is there no indentions in your code, it is very tough to read
Erik
I fix some of the errors you indicated me but still the code is not running properly. I can receive whatever i sent with the SMSString() but i can't receive the sms to the microcontroller and of course i can't get the phone number and the message from it. This is my fixed code
#include <reg51.h> #include <string.h> sbit Water=P2^0; sbit Window=P2^1; //declarations void clear(void); void tx0(unsigned char); void delay_sms (unsigned int); void SMSString(char*text) ; void init(); void Status(); void init_modem(); void process_modem_character(unsigned char *); unsigned char idata phone[15]; // Store received phone number unsigned char idata msg1[100]; // Store received message unsigned char j,abc; //unsigned char idata tmp10[27]; void serial () interrupt 4 using 1 { if(RI) //receive mode { RI=0; abc=SBUF; if(abc<100) { msg1[abc++]=SBUF; } else { RI=1; } } } void main (void) { clear(); init(); init_modem(); do { IE=0X90; // Enable serial interrupt delay_sms(1000); // i get a response like this // +CMGR: "REC UNREAD","+3069********",,"11/04/09,11:26:48+12" // Window on // OK // I think that's the format the 8051 get // \+CMTI\: \"SM\",1\r+CMGR: \"REC UNREAD\"\,\"+306982037789\"\,\,\"11\/04\/09\,11\:26\:48\+12\"\rStatus\n\rOK\r process_modem_character(msg1); // read sms and store it if(strncmp("Water on",msg1,8)==0) { Water=1; Status(); } else if(strncmp("Water off",msg1,9)==0) { Water=0; Status(); } else if(strncmp("Window on",msg1,9)==0) { Window=1; Status(); } else if(strncmp("Window off",msg1,10)==0) { Window=0; Status(); } else if(strncmp("Status",msg1,6)==0) { Status(); } else { SMSString("AT+CMGS=\""); SMSString(phone); SMSString("\"+<CR>\r"); delay_sms(1000); SMSString("Wrong Command"); SMSString("\n\r"); delay_sms(1000); SMSString(phone); delay_sms(1000); SMSString(msg1); delay_sms(1000); } SMSString("AT+CMGD=1\r"); delay_sms(1000); IE=0X00; // Disable serial interrupt delay_sms(1000); } while(1); } void init(void) { j=0; abc=0; TL1=0XFD; //9600 @ 11.0592 TH1=0xFD; TMOD=0x20; SCON=0x50; TR1=1; } void SMSString(unsigned char* text) //function to send SMS using GSM modem { while (*text) { tx0(*text++); } } void tx0(unsigned char x) //send data to serial port 0 { EA=0; SBUF=x; while(TI==0); TI=0; EA=1; } void delay_sms (unsigned int count) { unsigned int i; while(count) { i = 115; while(i>0) i--; count--; } } void init_modem(void) { Window=0; Water=0; SMSString("AT\r"); // AT commands to initialize gsm modem delay_sms(1000); SMSString( "ATe0\r"); // turn off echo delay_sms(1000); SMSString( "AT&W\r"); // save settings delay_sms(1000); SMSString( "AT+CMGF=1\r"); // select text mode for sms delay_sms(1000); SMSString( "AT+CNMI=2,1,0,0,0\r"); // notification of new sms delay_sms(1000); SMSString( "AT+CMGR=1\r"); // AT command to read sms delay_sms(1000); } void Status(void) { //tmp10 = sprintf( SBUF, "Water is %s and Window is %s\n" , Water, Window); SMSString("AT+CMGS=\""); SMSString(phone); SMSString("\"+<CR>"); delay_sms(1000); //SMSString(tmp10); SMSString("\n\r"); delay_sms(1000); } enum States { STATE_IDLE, STATE_FIND_CMT, STATE_CMT_GET_NUMBER, STATE_CMT_GET_COMMA, STATE_CMT_GET_MSG_START, STATE_CMT_GET_MSG, } state = STATE_IDLE; const char* pattern; int ch; void process_modem_character(unsigned char*msg) { switch (state) { case STATE_IDLE: if (msg == '+') { state = STATE_FIND_CMT; pattern = "\+CMTI\: \"SM\",1\r+CMGR: \"REC UNREAD\"\,\""; } break; case STATE_FIND_CMT: if (*pattern != msg) { state = STATE_IDLE; } else { pattern++; if (*pattern == '\0') { state = STATE_CMT_GET_NUMBER; ch = 0; } } break; case STATE_CMT_GET_NUMBER: if (msg == '\"') { state = STATE_CMT_GET_COMMA; } else if (ch >= sizeof(phone)) { // Too long phone number :( state = STATE_IDLE; } else { ch++; phone[ch] = *msg; phone[ch] = '\0'; } break; case STATE_CMT_GET_COMMA: if (msg == ' ') { ; // Ignore white space } else if (msg == ',') { state = STATE_CMT_GET_MSG_START; } else { // Invalid character received state = STATE_IDLE; } break; default: // Invalid state. state = STATE_IDLE; } // switch } // process_modem_character void clear(void) { unsigned char a; for(a=0;a<100;a++) msg1[a]=0x00; }
Please help
This is not how to receive data:
void serial () interrupt 4 using 1 { if (RI) { //receive mode RI=0; abc=SBUF; if(abc<100) { msg1[abc++]=SBUF; } else { RI=1; } } }
Seems more like random changes.
Look at standard example code for receiving serial data in interrupt handler. But abc (which you haven't still renamed to something meaningful) should not be assigned from SBUF - for every character received on the UART you may only read one (1) time from SBUF.
And you call process_modem_character(msg1) without caring if msg1 contains any characters. And your state machine doesn't consume any characters. And you have code like:
if (*pattern != msg) ...
but pattern is a pointer to char and msg is a pointer to unsigned char. Besides mixing char and unsigned char - what does the star do? *pattern would be the character pointed to by pattern. But msg is not a character but a pointer - comparing a character and a pointer isn't meaningful.
Try to implement a ring buffer or incomming data, and have your processing check if the ring buffer have data available. Then eat data and switch states depending on what you find. And keep track of pauses where you have no data or line endings to synchronize your state machine.
You don't get anything to work for the simple reason that you have neither tried to debug this code by running it and comparing what happens with what you expected, nor have you tried to just in your head evaluate these lines and figure out what values the different variables might have and what would happen if you step the code in your head. The major part of writing code is actually stepping the code in the head - we can't run a debugger until we have code, but we must be able to read and understand without debugger to be able to write the code in the first place.
void serial () interrupt 4 using 1 { if (RI) { //receive mode RI=0; abc=SBUF; if(abc<100) { msg1[abc++]=SBUF; } else { RI=1; /////////// this will get you right back into the ISR } } }
I had to reformat your code to verufy this, what is wrong with lining the braces up???, look at the comment above.
abc=SBUF; .... msg1[abc++]=SBUF;
storing in a buffer indexed by the hex value of the character received?????
It looks to me as if you do not believe in the adage "think before you do"
Brace positioning is very much a matter of strongly-held personal preference.
Many people like their braces on the end of the "controlling" line:
if( test ) { // stuff } else { // alternative stuff }
Some people (like me) like their braces alone on a line, aligned with the "controlling" line
Some people (quite inexplicably, IMO) like their braces alone on a line, aligned with the "controlled" line(s)
To name but three.
The important thing is, whatever you choose, to be consistent
plenty more here: en.wikipedia.org/.../Indent_style