File content as of revision 2:8352ad91f2ee:

#include "GSMLibrary.h"
#include "gsmqueue.h"
#include <string.h>

#define TIME_CONST 1
#define SECONDS_TIMEOUT 10
#define TIMEOUTLIMIT TIME_CONST //$change check with main code this will set up condition fior timeout.

//definition for AT comands
#define AT_OK "AT"
#define AT_CSQ "AT+CSQ" 
#define AT_CREG "AT+CREG?"
#define AT_CMGF "AT+CMGF=1"
#define RECEIVER_PHONE_NUMBER "\"+18014722842\""
#define AT_CMGS "AT+CMGS=" RECEIVER_PHONE_NUMBER 

//Definition for at repsonses
//Please notice that after ":" the gsm will usually send aditional information
#define AT_OK_RESPONSE "OK" //Response after sending "AT" message
#define AT_CSQ_RESPONSE "+CSQ:" //+CSQ: <arg1>,<arg2> where <arg1> is signal strenght arg1 = 0-30 where a number below 10 means low signal strength and 99 is not knwn or detectable signal and arg2 is bit error rate form 0-7, 99 will represent error 
#define AT_CREG_RESPONSE "+CREG:"//+CREG: <arg1>,<arg2> where <arg1> = 0-2(see at comand descriptions), <arg2> =  0-5, 0 not registered to nework and not looking for one. 1 is conected to network, 2 is not conected but searching
#define AT_CMGF_RESPONSE "OK"
#define AT_CMGS_RESPONSE ">" //Message is written aftersymbol
#define AT_SENDSMS_RESPONSE "+CMGS:" // +CMGS: <id> this will include the message id. CMGS ERROR for error and 
#define AT_SUCCESS_REPSONSE "OK"


extern Serial pc;
extern Serial gsm;
extern uint8_t buffer[BUFFER_LENGTH];//buffer storing char
gsm_states gsm_current_state = GSM_INITIALIZE;

char correct = 0;
char send = 0;
char timeout_count = 0;
char received = 0;
char timeout_limit = TIMEOUTLIMIT;

void gsm_tick(){
    
    //post action
    switch(gsm_current_state){
        //when send flag is on , send AT_OK message to gsm.
        case GSM_INITIALIZE:
            pc.printf("gsm_initilize state\r\n");//&debug
            correct = 0;
            timeout_count = 0;
            received = 0;
            if(send){ //send first at_ok message
                 resetGSMIdleBit();
                 pc.printf("sending AT_OK\r\n");//&debug
                 gsm.puts(AT_OK);
                 gsm.puts("\r\n"); 
                 gsm_current_state = GSM_AT_OK;
            }
            else
                gsm_current_state = GSM_INITIALIZE;
            break;
         // check for repsonse to AT and if correct send AT+CSQ message   
        case GSM_AT_OK:
        timeout_count++;
        pc.printf("inside AT_OK state\r\n");//&debug
            if(getGSMIdleBit()){
                printQueue(); //$debug 
                if(findInQueue(AT_OK)){
                    timeout_count = 0;
                    resetGSMIdleBit();
                    pc.printf("sending AT_CSQ\r\n");//&debug
                    gsm.puts(AT_CSQ);
                    gsm.puts("\r\n"); 
                    gsm_current_state = GSM_AT_CSQ;
                }
                else
                    gsm_current_state = GSM_INITIALIZE;
            }
            if(timeout_count >= timeout_limit)
                gsm_current_state = GSM_INITIALIZE;
            break;
            
        case GSM_AT_CSQ:
            gsm_current_state = GSM_AT_CREG;
            break;
        case GSM_AT_CREG:
            gsm_current_state = GSM_AT_CMGF;
            break;
        case GSM_AT_CMGF:
            gsm_current_state = GSM_AT_CMGS;
            break;
        case GSM_AT_CMGS:
            gsm_current_state = GSM_AT_SENDSMS;
            break;
        case GSM_AT_SENDSMS:
            gsm_current_state = GSM_SUCCESS;
            break;
        case GSM_SUCCESS:
            gsm_current_state = GSM_INITIALIZE;
            break;
        default:
            pc.printf("This is a state error");
    }
    
}

//
void gsm_reset();


//
void gsm_initialize(){    
     SIM_SCGC6 |= SIM_SCGC6_DMAMUX_MASK;
      SIM_SCGC7 |= SIM_SCGC7_DMA_MASK;  
      pc.printf("initializing tregisters...!\r\n");
     // control register mux, enabling uart3 receive        
     DMAMUX_CHCFG0 |= DMAMUX_CHCFG_ENBL_MASK|DMAMUX_CHCFG_SOURCE(8); 
     
     // Enable request signal for channel 0 
     DMA_ERQ = DMA_ERQ_ERQ0_MASK;
     
      // select round-robin arbitration priority
     DMA_CR |= DMA_CR_ERCA_MASK;
     
     //enabled error interrupt for DMA0
     //DMA_EEI = DMA_EEI_EEI0_MASK ;
     //Addres for buffer
     DMA_TCD0_SADDR = (uint32_t) &UART_D_REG(UART3_BASE_PTR);
     DMA_TCD0_DADDR = (uint32_t) buffer;
     // Set an offset for source and destination address
     DMA_TCD0_SOFF = 0x00; 
     DMA_TCD0_DOFF = 0x01; // Destination address offset of 1 byte per transaction
     
     // Set source and destination data transfer size
     DMA_TCD0_ATTR = DMA_ATTR_SSIZE(0) | DMA_ATTR_DSIZE(0);
     
     // Number of bytes to be transfered in each service request of the channel
     DMA_TCD0_NBYTES_MLNO = 0x01;
     // Current major iteration count
    DMA_TCD0_CITER_ELINKNO = DMA_CITER_ELINKNO_CITER(BUFFER_LENGTH);
    DMA_TCD0_BITER_ELINKNO = DMA_BITER_ELINKNO_BITER(BUFFER_LENGTH);
    // Adjustment value used to restore the source and destiny address to the initial value
    // After reading 'len' number of times, the DMA goes back to the beginning by subtracting len*2 from the address (going back to the original address)
    DMA_TCD0_SLAST = 0;      // Source address adjustment
    DMA_TCD0_DLASTSGA = -BUFFER_LENGTH;  // Destination address adjustment     
    // Setup control and status register
    DMA_TCD0_CSR = 0;
       
    // enable interrupt call at end of major loop
    DMA_TCD0_CSR |= DMA_CSR_INTMAJOR_MASK;
    
    //Activate dma trasnfer rx interrupt
    UART_C2_REG(UART3) |= UART_C2_RIE_MASK;
    UART_C5_REG(UART3) |= UART_C5_RDMAS_MASK | UART_C5_ILDMAS_MASK | UART_C5_LBKDDMAS_MASK;
    //activate p fifo   
    UART_PFIFO_REG(UART3) |= UART_PFIFO_RXFE_MASK; //RXFE and buffer size of 1 word
    pc.printf("Initialization done...\n\r");
}



//initialization debuging purposes
void print_registers() {
    
   
    pc.printf("\n\rDMA REGISTERS\n\r");
    pc.printf("DMA_MUX: 0x%08x\r\n",DMAMUX_CHCFG0);
    pc.printf("SADDR0: 0x%08x\r\n",DMA_TCD0_SADDR);
    pc.printf("DADDR0: 0x%08x\r\n",DMA_TCD0_DADDR);
    pc.printf("CITER0: 0x%08x\r\n",DMA_TCD0_CITER_ELINKNO);
    pc.printf("BITER0: 0x%08x\r\n",DMA_TCD0_BITER_ELINKNO);
    pc.printf("DMA_CR: %08x\r\n", DMA_CR);
    pc.printf("DMA_ES: %08x\r\n", DMA_ES);
    pc.printf("DMA_ERQ: %08x\r\n", DMA_ERQ);
    pc.printf("DMA_EEI: %08x\r\n", DMA_EEI);
    pc.printf("DMA_CEEI: %02x\r\n", DMA_CEEI);
    pc.printf("DMA_SEEI: %02x\r\n", DMA_SEEI);
    pc.printf("DMA_CERQ: %02x\r\n", DMA_CERQ);
    pc.printf("DMA_SERQ: %02x\r\n", DMA_SERQ);
    pc.printf("DMA_CDNE: %02x\r\n", DMA_CDNE);
    pc.printf("DMA_SSRT: %02x\r\n", DMA_SSRT);
    pc.printf("DMA_CERR: %02x\r\n", DMA_CERR);
    pc.printf("DMA_CINT: %02x\r\n", DMA_CINT);
    pc.printf("DMA_INT: %08x\r\n", DMA_INT);
    pc.printf("DMA_ERR: %08x\r\n", DMA_ERR);
    pc.printf("DMA_HRS: %08x\r\n", DMA_HRS);
    pc.printf("DMA_TCD0_DOFF: %08x\r\n",DMA_TCD0_DOFF);
    pc.printf("\n\rUART REGISTERS\n\r");
    pc.printf("UART_BDH_REG: %08x\r\n",UART_BDH_REG(UART3)); 
    pc.printf("UART_C1_REG: %08x\r\n",UART_C1_REG(UART3));
    pc.printf("UART_C2_REG: %08x\r\n",UART_C2_REG(UART3));
    pc.printf("UART_S1_REG: %08x\r\n",UART_S1_REG(UART3));
    pc.printf("UART_s2_REG: %08x\r\n",UART_S2_REG(UART3));    
    pc.printf("UART_C3_REG: %08x\r\n",UART_C3_REG(UART3));
    pc.printf("UART_D_REG: %08x\r\n",UART_D_REG(UART3));
    pc.printf("UART_MA1_REG: %08x\r\n",UART_MA1_REG(UART3));
    pc.printf("UART_MA2_REG: %08x\r\n",UART_MA2_REG(UART3));
    pc.printf("UART_C4_REG: %08x\r\n",UART_C4_REG(UART3));
    pc.printf("UART_C5_REG: %08x\r\n",UART_C5_REG(UART3));
    pc.printf("UART_ED_REG: %08x\r\n",UART_ED_REG(UART3));       
    pc.printf("UART_MODEM_REG: %08x\r\n",UART_MODEM_REG(UART3));
    pc.printf("UART_IR_REG: %08x\r\n",UART_IR_REG(UART3)); 
    pc.printf("UART_PFIFO_REG: %08x\r\n",UART_PFIFO_REG(UART3));
    pc.printf("UART_CFIFO_REG: %08x\r\n",UART_CFIFO_REG(UART3));
    pc.printf("UART_SFIFO_REG: %08x\r\n",UART_SFIFO_REG(UART3)); 
    pc.printf("UART_TWFIFO_REG: %08x\r\n",UART_TWFIFO_REG(UART3));
    pc.printf("UART_TCFIFO_REG: %08x\r\n",UART_TCFIFO_REG(UART3)); 
    pc.printf("UART_RWFIFO_REG: %08x\r\n",UART_RWFIFO_REG(UART3)); 
    pc.printf("UART_RCFIFO_REG: %08x\r\n",UART_RCFIFO_REG(UART3));
  
}