DFRobot_sim808.cpp

/*!
 * @file DFRobot_sim808.cpp
 * @A library  for DFRobot's SIM808 GPS/DFRobot_SIM808/GSM Shield
 *
 * @copyright	[DFRobot](http://www.dfrobot.com), 2016
 *
 * @author [Jason](jason.ling@dfrobot.com)
 * @version  V1.0
 * @date  2016-09-23
 
 * The MIT License (MIT)
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
 

#include <stdio.h>
#include "DFRobot_sim808.h"

extern Stream *serialSIM808;

DFRobot_SIM808* DFRobot_SIM808::inst;
char receivedStackIndex = 0;
char receivedStack[130];
const char *des = "$GPRMC";

//char *receivedStack="$GPRMC,165445.000,A,3110.8635,N,12133.4627,E,0.58,70.26,220916,,,A*57";

DFRobot_SIM808::DFRobot_SIM808(HardwareSerial *mySerial)
{
    inst = this;	
	serialFlag = 1;
	hgprsSerial = mySerial;
    sim808_init(mySerial, 1);
}

DFRobot_SIM808::DFRobot_SIM808(SoftwareSerial *mySerial)
{
    inst = this;
	serialFlag = 0;
	gprsSerial = mySerial;
   sim808_init(mySerial, 0);
}

bool DFRobot_SIM808::init(void)
{
    //閿熸枻鎷烽敓绱窽鎸囬敓鏂ゆ嫹閿熻鍑ゆ嫹閿熸枻鎷锋晥
	if(!sim808_check_with_cmd("AT\r\n","OK\r\n",CMD)){   
	    
		return false;
		
    }
	//閿熸枻鎷烽敓绲奍M閿熻鍑ゆ嫹閿熸枻鎷锋簮閿熺晫璇濋敓鏂ゆ嫹閿熸枻鎷烽敓鏂ゆ嫹閿熸枻鎷�
	// 1 : OK
    if(!sim808_check_with_cmd("AT+CFUN=1\r\n","OK\r\n",CMD)){
        return false;
    }

	//閿熸枻鎷烽敓绲奍M閿熸枻鎷风姸鎬�
    if(!checkSIMStatus()) {
		return false;
    }
    return true;
}

bool DFRobot_SIM808::checkPowerUp(void)
{
  return sim808_check_with_cmd("AT\r\n","OK\r\n",CMD);
}

void DFRobot_SIM808::powerUpDown(uint8_t pin)
{
  // power on pulse for SIM900 Shield
  digitalWrite(pin,LOW);
  delay(1000);
  digitalWrite(pin,HIGH);
  delay(2000);
  digitalWrite(pin,LOW);
  delay(3000);
}

void DFRobot_SIM808::powerReset(uint8_t pin)
{
  // reset for SIM800L board.
  // RST pin has to be OUTPUT, HIGH
  digitalWrite(pin,LOW);
  delay(1000);
  digitalWrite(pin,HIGH);
  delay(3000);  
}
  
  
bool DFRobot_SIM808::checkSIMStatus(void)
{
    char gprsBuffer[32];
    int count = 0;
    sim808_clean_buffer(gprsBuffer,32);
    while(count < 3) {
        sim808_send_cmd("AT+CPIN?\r\n");
        sim808_read_buffer(gprsBuffer,32,DEFAULT_TIMEOUT);
        if((NULL != strstr(gprsBuffer,"+CPIN: READY"))) {  //閿熸枻鎷风ずSIM鐘舵€侀敓鏂ゆ嫹閿熸枻鎷�
            break;
        }
        count++;
        delay(300);
    }
    if(count == 3) {
        return false;
    }
    return true;
}

bool DFRobot_SIM808::sendSMS(char *number, char *data)
{
    //char cmd[32];
    if(!sim808_check_with_cmd("AT+CMGF=1\r\n", "OK\r\n", CMD)) { // Set message mode to ASCII
        return false;
    }
    delay(500);
	sim808_flush_serial();
	sim808_send_cmd("AT+CMGS=\"");
	sim808_send_cmd(number);
    //sprintf(cmd,"AT+CMGS=\"%s\"\r\n", number);
	//snprintf(cmd, sizeof(cmd),"AT+CMGS=\"%s\"\r\n", number);
//    if(!sim808_check_with_cmd(cmd,">",CMD)) {
    if(!sim808_check_with_cmd("\"\r\n",">",CMD)) {
        return false;
    }
    delay(1000);
    sim808_send_cmd(data);
    delay(500);
    sim808_send_End_Mark();
    return sim808_wait_for_resp("OK\r\n", CMD);
}

char DFRobot_SIM808::isSMSunread()
{
    char gprsBuffer[48];  //48 is enough to see +CMGL:
    char *s;
    
	 sim808_check_with_cmd("AT+CMGF=1\r\n","OK\r\n",CMD);
    delay(1000);

    //List of all UNREAD SMS and DON'T change the SMS UNREAD STATUS
    sim808_send_cmd(F("AT+CMGL=\"REC UNREAD\",1\r\n"));
    /*If you want to change SMS status to READ you will need to send:
          AT+CMGL=\"REC UNREAD\"\r\n
      This command will list all UNREAD SMS and change all of them to READ
      
     If there is not SMS, response is (30 chars)
         AT+CMGL="REC UNREAD",1  --> 22 + 2
                                 --> 2
         OK                      --> 2 + 2

     If there is SMS, response is like (>64 chars)
         AT+CMGL="REC UNREAD",1
         +CMGL: 9,"REC UNREAD","XXXXXXXXX","","14/10/16,21:40:08+08"
         Here SMS text.
         OK  
         
         or

         AT+CMGL="REC UNREAD",1
         +CMGL: 9,"REC UNREAD","XXXXXXXXX","","14/10/16,21:40:08+08"
         Here SMS text.
         +CMGL: 10,"REC UNREAD","YYYYYYYYY","","14/10/16,21:40:08+08"
         Here second SMS        
         OK           
    */

    sim808_clean_buffer(gprsBuffer,31); 
    sim808_read_buffer(gprsBuffer,30,DEFAULT_TIMEOUT); 
    //Serial.print("Buffer isSMSunread: ");Serial.println(gprsBuffer);

    if(NULL != ( s = strstr(gprsBuffer,"OK"))) {
        //In 30 bytes "doesn't" fit whole +CMGL: response, if recieve only "OK"
        //    means you don't have any UNREAD SMS
        delay(50);
        return 0;
    } else {
        //More buffer to read
        //We are going to flush serial data until OK is recieved
        sim808_wait_for_resp("OK\r\n", CMD);        
        //sim808_flush_serial();
        //We have to call command again
        sim808_send_cmd("AT+CMGL=\"REC UNREAD\",1\r\n");
        sim808_clean_buffer(gprsBuffer,48); 
        sim808_read_buffer(gprsBuffer,47,DEFAULT_TIMEOUT);
		//Serial.print("Buffer isSMSunread 2: ");Serial.println(gprsBuffer);       
        if(NULL != ( s = strstr(gprsBuffer,"+CMGL:"))) {
            //There is at least one UNREAD SMS, get index/position
            s = strstr(gprsBuffer,":");
            if (s != NULL) {
                //We are going to flush serial data until OK is recieved
                sim808_wait_for_resp("OK\r\n", CMD);
                return atoi(s+1);
            }
        } else {
            return -1; 

        }
    } 
    return -1;
}

bool DFRobot_SIM808::readSMS(int messageIndex, char *message, int length, char *phone, char *datetime)  
{
  /* Response is like:
  AT+CMGR=2
  
  +CMGR: "REC READ","XXXXXXXXXXX","","14/10/09,17:30:17+08"
  SMS text here
  
  So we need (more or lees), 80 chars plus expected message length in buffer. CAUTION FREE MEMORY
  */

    int i = 0;
    char gprsBuffer[80 + length];
    //char cmd[16];
	char num[4];
    char *p,*p2,*s;
    
    sim808_check_with_cmd("AT+CMGF=1\r\n","OK\r\n",CMD);
    delay(1000);
	//sprintf(cmd,"AT+CMGR=%d\r\n",messageIndex);
    //sim808_send_cmd(cmd);
	sim808_send_cmd("AT+CMGR=");
	itoa(messageIndex, num, 10);
	sim808_send_cmd(num);
	sim808_send_cmd("\r\n");
    sim808_clean_buffer(gprsBuffer,sizeof(gprsBuffer));
    sim808_read_buffer(gprsBuffer,sizeof(gprsBuffer));
      
    if(NULL != ( s = strstr(gprsBuffer,"+CMGR:"))){
        // Extract phone number string
        p = strstr(s,",");
        p2 = p + 2; //We are in the first phone number character
        p = strstr((char *)(p2), "\"");
        if (NULL != p) {
            i = 0;
            while (p2 < p) {
                phone[i++] = *(p2++);
            }
            phone[i] = '\0';            
        }
        // Extract date time string
        p = strstr((char *)(p2),",");
        p2 = p + 1; 
        p = strstr((char *)(p2), ","); 
        p2 = p + 2; //We are in the first date time character
        p = strstr((char *)(p2), "\"");
        if (NULL != p) {
            i = 0;
            while (p2 < p) {
                datetime[i++] = *(p2++);
            }
            datetime[i] = '\0';
        }        
        if(NULL != ( s = strstr(s,"\r\n"))){
            i = 0;
            p = s + 2;
            while((*p != '\r')&&(i < length-1)) {
                message[i++] = *(p++);
            }
            message[i] = '\0';
        }
        return true;
    }
    return false;    
}

bool DFRobot_SIM808::readSMS(int messageIndex, char *message,int length)
{
    int i = 0;
    char gprsBuffer[100];
    //char cmd[16];
	char num[4];
    char *p,*s;
	
    sim808_check_with_cmd("AT+CMGF=1\r\n","OK\r\n",CMD);
    delay(1000);
	sim808_send_cmd("AT+CMGR=");
	itoa(messageIndex, num, 10);
	sim808_send_cmd(num);
	sim808_send_cmd("\r\n");
//  sprintf(cmd,"AT+CMGR=%d\r\n",messageIndex);
//    sim808_send_cmd(cmd);
    sim808_clean_buffer(gprsBuffer,sizeof(gprsBuffer));
    sim808_read_buffer(gprsBuffer,sizeof(gprsBuffer),DEFAULT_TIMEOUT);
    if(NULL != ( s = strstr(gprsBuffer,"+CMGR:"))){
        if(NULL != ( s = strstr(s,"\r\n"))){
            p = s + 2;
            while((*p != '\r')&&(i < length-1)) {
                message[i++] = *(p++);
            }
            message[i] = '\0';
            return true;
        }
    }
    return false;   
}

bool DFRobot_SIM808::deleteSMS(int index)
{
    //char cmd[16];
	char num[4];
    //sprintf(cmd,"AT+CMGD=%d\r\n",index);
    sim808_send_cmd("AT+CMGD=");
	itoa(index, num, 10);
	sim808_send_cmd(num);
	//snprintf(cmd,sizeof(cmd),"AT+CMGD=%d\r\n",index);
    //sim808_send_cmd(cmd);
    //return 0;
    // We have to wait OK response
	//return sim808_check_with_cmd(cmd,"OK\r\n",CMD);
	return sim808_check_with_cmd("\r","OK\r\n",CMD);	
}

bool DFRobot_SIM808::callUp(char *number)
{
    //char cmd[24];
    if(!sim808_check_with_cmd("AT+COLP=1\r\n","OK\r\n",CMD)) {
        return false;
    }
    delay(1000);
	//HACERR quitar SPRINTF para ahorar memoria ???
    //sprintf(cmd,"ATD%s;\r\n", number);
    //sim808_send_cmd(cmd);
	sim808_send_cmd("ATD");
	sim808_send_cmd(number);
	sim808_send_cmd(";\r\n");
    return true;
}

void DFRobot_SIM808::answer(void)
{
    sim808_send_cmd("ATA\r\n");  //TO CHECK: ATA doesnt return "OK" ????
}

bool DFRobot_SIM808::hangup(void)
{
    return sim808_check_with_cmd("ATH\r\n","OK\r\n",CMD);
}

bool DFRobot_SIM808::disableCLIPring(void)
{
    return sim808_check_with_cmd("AT+CLIP=0\r\n","OK\r\n",CMD);
}

bool DFRobot_SIM808::getSubscriberNumber(char *number)
{
	//AT+CNUM								--> 7 + CR = 8
	//+CNUM: "","+628157933874",145,7,4		--> CRLF + 45 + CRLF = 49
	//										-->
	//OK									--> CRLF + 2 + CRLF = 6

    byte i = 0;
    char gprsBuffer[65];
    char *p,*s;
	sim808_flush_serial();
    sim808_send_cmd("AT+CNUM\r\n");
    sim808_clean_buffer(gprsBuffer,65);
    sim808_read_buffer(gprsBuffer,65,DEFAULT_TIMEOUT);
	//Serial.print(gprsBuffer);
    if(NULL != ( s = strstr(gprsBuffer,"+CNUM:"))) {
        s = strstr((char *)(s),",");
        s = s + 2;  //We are in the first phone number character 
        p = strstr((char *)(s),"\""); //p is last character """
        if (NULL != s) {
            i = 0;
            while (s < p) {
              number[i++] = *(s++);
            }
            number[i] = '\0';
        }
        return true;
    }  
    return false;
}

bool DFRobot_SIM808::isCallActive(char *number)
{
    char gprsBuffer[46];  //46 is enough to see +CPAS: and CLCC:
    char *p, *s;
    int i = 0;

    sim808_send_cmd("AT+CPAS\r\n");
    /*Result code:
        0: ready
        2: unknown
        3: ringing
        4: call in progress
    
      AT+CPAS   --> 7 + 2 = 9 chars
                --> 2 char              
      +CPAS: 3  --> 8 + 2 = 10 chars
                --> 2 char
      OK        --> 2 + 2 = 4 chars
    
      AT+CPAS
      
      +CPAS: 0
      
      OK
    */

    sim808_clean_buffer(gprsBuffer,29);
    sim808_read_buffer(gprsBuffer,27);
    //HACERR cuando haga lo de esperar a OK no me har閾哸 falta esto
    //We are going to flush serial data until OK is recieved
    sim808_wait_for_resp("OK\r\n", CMD);    
    //Serial.print("Buffer isCallActive 1: ");Serial.println(gprsBuffer);
    if(NULL != ( s = strstr(gprsBuffer,"+CPAS:"))) {
      s = s + 7;
      if (*s != '0') {
         //There is something "running" (but number 2 that is unknow)
         if (*s != '2') {
           //3 or 4, let's go to check for the number
           sim808_send_cmd("AT+CLCC\r\n");
           /*
           AT+CLCC --> 9
           
           +CLCC: 1,1,4,0,0,"656783741",161,""
           
           OK  

           Without ringing:
           AT+CLCC
           OK              
           */

           sim808_clean_buffer(gprsBuffer,46);
           sim808_read_buffer(gprsBuffer,45);
			//Serial.print("Buffer isCallActive 2: ");Serial.println(gprsBuffer);
           if(NULL != ( s = strstr(gprsBuffer,"+CLCC:"))) {
             //There is at least one CALL ACTIVE, get number
             s = strstr((char *)(s),"\"");
             s = s + 1;  //We are in the first phone number character            
             p = strstr((char *)(s),"\""); //p is last character """
             if (NULL != s) {
                i = 0;
                while (s < p) {
                    number[i++] = *(s++);
                }
                number[i] = '\0';            
             }
             //I need to read more buffer
             //We are going to flush serial data until OK is recieved
             return sim808_wait_for_resp("OK\r\n", CMD); 
           }
         }
      }        
    } 
    return false;
}

bool DFRobot_SIM808::getDateTime(char *buffer)
{
	//If it doesn't work may be for two reasons:
	//		1. Your carrier doesn't give that information
	//		2. You have to configurate the SIM808 IC.
	//			- First with SIM808_Serial_Debug example try this AT command: AT+CLTS?
	//			- If response is 0, then it is disabled.
	//			- Enable it by: AT+CLTS=1
	//			- Now you have to save this config to EEPROM memory of SIM808 IC by: AT&W
	//			- Now, you have to power down and power up again the SIM808 
	//			- Try now again: AT+CCLK?
	//			- It should work
	
	//AT+CCLK?						--> 8 + CR = 9
	//+CCLK: "14/11/13,21:14:41+04"	--> CRLF + 29+ CRLF = 33
	//								
	//OK							--> CRLF + 2 + CRLF =  6

    byte i = 0;
    char gprsBuffer[50];
    char *p,*s;
	sim808_flush_serial();
    sim808_send_cmd("AT+CCLK?\r");
    sim808_clean_buffer(gprsBuffer,50);
    sim808_read_buffer(gprsBuffer,50,DEFAULT_TIMEOUT);
    if(NULL != ( s = strstr(gprsBuffer,"+CCLK:"))) {
        s = strstr((char *)(s),"\"");
        s = s + 1;  //We are in the first phone number character 
        p = strstr((char *)(s),"\""); //p is last character """
        if (NULL != s) {
            i = 0;
            while (s < p) {
              buffer[i++] = *(s++);
            }
            buffer[i] = '\0';            
        }
        return true;
    }  
    return false;
}

bool DFRobot_SIM808::getSignalStrength(int *buffer)
{
	//AT+CSQ						--> 6 + CR = 10
	//+CSQ: <rssi>,<ber>			--> CRLF + 5 + CRLF = 9						
	//OK							--> CRLF + 2 + CRLF =  6

	byte i = 0;
	char gprsBuffer[26];
	char *p, *s;
	char buffers[4];
	sim808_flush_serial();
	sim808_send_cmd("AT+CSQ\r");
	sim808_clean_buffer(gprsBuffer, 26);
	sim808_read_buffer(gprsBuffer, 26, DEFAULT_TIMEOUT);
	if (NULL != (s = strstr(gprsBuffer, "+CSQ:"))) {
		s = strstr((char *)(s), " ");
		s = s + 1;  //We are in the first phone number character 
		p = strstr((char *)(s), ","); //p is last character """
		if (NULL != s) {
			i = 0;
			while (s < p) {
				buffers[i++] = *(s++);
			}
			buffers[i] = '\0';
		}
		*buffer = atoi(buffers);
		return true;
	}
	return false;
}

bool DFRobot_SIM808::sendUSSDSynchronous(char *ussdCommand, char *resultcode, char *response)
{
	//AT+CUSD=1,"{command}"
	//OK
	//
	//+CUSD:1,"{response}",{int}

	byte i = 0;
    char gprsBuffer[200];
    char *p,*s;
    sim808_clean_buffer(response, sizeof(response));
	
	sim808_flush_serial();
    sim808_send_cmd("AT+CUSD=1,\"");
    sim808_send_cmd(ussdCommand);
    sim808_send_cmd("\"\r");
	if(!sim808_wait_for_resp("OK\r\n", CMD))
		return false;
    sim808_clean_buffer(gprsBuffer,200);
    sim808_read_buffer(gprsBuffer,200,DEFAULT_TIMEOUT);
    if(NULL != ( s = strstr(gprsBuffer,"+CUSD: "))) {
        *resultcode = *(s+7);
		resultcode[1] = '\0';
		if(!('0' <= *resultcode && *resultcode <= '2'))
			return false;
		s = strstr(s,"\"");
        s = s + 1;  //We are in the first phone number character
        p = strstr(s,"\""); //p is last character """
        if (NULL != s) {
            i = 0;
            while (s < p) {
              response[i++] = *(s++);
            }
            response[i] = '\0';            
        }
		return true;
	}
	return false;
}

bool DFRobot_SIM808::cancelUSSDSession(void)
{
    return sim808_check_with_cmd("AT+CUSD=2\r\n","OK\r\n",CMD);
}

//Here is where we ask for APN configuration, with F() so we can save MEMORY
bool DFRobot_SIM808::join(const __FlashStringHelper *apn, const __FlashStringHelper *userName, const __FlashStringHelper *passWord)
{
	byte i;
    char *p, *s;
    char ipAddr[32];
    //Select multiple connection
    //sim808_check_with_cmd("AT+CIPMUX=1\r\n","OK",DEFAULT_TIMEOUT,CMD);

    //set APN. OLD VERSION
    //snprintf(cmd,sizeof(cmd),"AT+CSTT=\"%s\",\"%s\",\"%s\"\r\n",_apn,_userName,_passWord);
    //sim808_check_with_cmd(cmd, "OK\r\n", DEFAULT_TIMEOUT,CMD);
    sim808_send_cmd("AT+CSTT=\"");
    if (apn) {
      sim808_send_cmd(apn);
    }
    sim808_send_cmd("\",\"");
    if (userName) {
      sim808_send_cmd(userName);
    }
    sim808_send_cmd("\",\"");
    if (passWord) {
      sim808_send_cmd(passWord);
    }
    sim808_check_with_cmd("\"\r\n", "OK\r\n", CMD);
    

    //Brings up wireless connection
    sim808_check_with_cmd("AT+CIICR\r\n","OK\r\n", CMD);

    //Get local IP address
    sim808_send_cmd("AT+CIFSR\r\n");
    sim808_clean_buffer(ipAddr,32);
    sim808_read_buffer(ipAddr,32);
	//Response:
	//AT+CIFSR\r\n       -->  8 + 2
	//\r\n				 -->  0 + 2
	//10.160.57.120\r\n  --> 15 + 2 (max)   : TOTAL: 29 
	//Response error:
	//AT+CIFSR\r\n       
	//\r\n				 
	//ERROR\r\n
    if (NULL != strstr(ipAddr,"ERROR")) {
		return false;
	}
    s = ipAddr + 11;
    p = strstr((char *)(s),"\r\n"); //p is last character \r\n
    if (NULL != s) {
        i = 0;
        while (s < p) {
            ip_string[i++] = *(s++);
        }
        ip_string[i] = '\0';            
    }
    _ip = str_to_ip(ip_string);
    if(_ip != 0) {
        return true;
    }
    return false;
} 

void DFRobot_SIM808::disconnect()
{
    sim808_send_cmd("AT+CIPSHUT\r\n");
}

bool DFRobot_SIM808::connect(Protocol ptl,const char * host, int port, int timeout, int chartimeout)
{
    //char cmd[64];
	char num[4];
    char resp[96];

    //sim808_clean_buffer(cmd,64);
    if(ptl == TCP) {
		sim808_send_cmd("AT+CIPSTART=\"TCP\",\"");
		sim808_send_cmd(host);
		sim808_send_cmd("\",");
		itoa(port, num, 10);
		sim808_send_cmd(num);
		sim808_send_cmd("\r\n");
//        sprintf(cmd, "AT+CIPSTART=\"TCP\",\"%s\",%d\r\n",host, port);
    } else if(ptl == UDP) {
		sim808_send_cmd("AT+CIPSTART=\"UDP\",\"");
		sim808_send_cmd(host);
		sim808_send_cmd("\",");
		itoa(port, num, 10);
		sim808_send_cmd(num);
		sim808_send_cmd("\r\n");

	//        sprintf(cmd, "AT+CIPSTART=\"UDP\",\"%s\",%d\r\n",host, port);
    } else {
        return false;
    }
    

    //sim808_send_cmd(cmd);
    sim808_read_buffer(resp, 96, timeout, chartimeout);
	//Serial.print("Connect resp: "); Serial.println(resp);    
    if(NULL != strstr(resp,"CONNECT")) { //ALREADY CONNECT or CONNECT OK
        return true;
    }
    return false;
}

//Overload with F() macro to SAVE memory
bool DFRobot_SIM808::connect(Protocol ptl,const __FlashStringHelper *host, const __FlashStringHelper *port, int timeout, int chartimeout)
{
    //char cmd[64];
    char resp[96];

    //sim808_clean_buffer(cmd,64);
    if(ptl == TCP) {
        sim808_send_cmd(F("AT+CIPSTART=\"TCP\",\""));   //%s\",%d\r\n",host, port);
    } else if(ptl == UDP) {
        sim808_send_cmd(F("AT+CIPSTART=\"UDP\",\""));   //%s\",%d\r\n",host, port);
    } else {
        return false;
    }
    sim808_send_cmd(host);
    sim808_send_cmd(F("\","));
    sim808_send_cmd(port);
    sim808_send_cmd(F("\r\n"));
//	Serial.print("Connect: "); Serial.println(cmd);
    sim808_read_buffer(resp, 96, timeout, chartimeout);
//	Serial.print("Connect resp: "); Serial.println(resp);    
    if(NULL != strstr(resp,"CONNECT")) { //ALREADY CONNECT or CONNECT OK
        return true;
    }
    return false;
}

bool DFRobot_SIM808::is_connected(void)
{
    char resp[96];
    sim808_send_cmd("AT+CIPSTATUS\r\n");
    sim808_read_buffer(resp,sizeof(resp),DEFAULT_TIMEOUT);
    if(NULL != strstr(resp,"CONNECTED")) {
        //+CIPSTATUS: 1,0,"TCP","216.52.233.120","80","CONNECTED"
        return true;
    } else {
        //+CIPSTATUS: 1,0,"TCP","216.52.233.120","80","CLOSED"
        //+CIPSTATUS: 0,,"","","","INITIAL"
        return false;
    }
}

bool DFRobot_SIM808::close()
{
    // if not connected, return
    if (!is_connected()) {
        return true;
    }
    return sim808_check_with_cmd("AT+CIPCLOSE\r\n", "CLOSE OK\r\n", CMD);
}

int DFRobot_SIM808::readable(void)
{
    return sim808_check_readable();
}

int DFRobot_SIM808::wait_readable(int wait_time)
{
    return sim808_wait_readable(wait_time);
}

int DFRobot_SIM808::wait_writeable(int req_size)
{
    return req_size+1;
}

int DFRobot_SIM808::send(const char * str, int len)
{
    //char cmd[32];
	char num[4];
    if(len > 0){
        //snprintf(cmd,sizeof(cmd),"AT+CIPSEND=%d\r\n",len);
		//sprintf(cmd,"AT+CIPSEND=%d\r\n",len);
		sim808_send_cmd("AT+CIPSEND=");
		itoa(len, num, 10);
		sim808_send_cmd(num);
		if(!sim808_check_with_cmd("\r\n",">",CMD)) {
        //if(!sim808_check_with_cmd(cmd,">",CMD)) {
            return 0;
        }
        /*if(0 != sim808_check_with_cmd(str,"SEND OK\r\n", DEFAULT_TIMEOUT * 10 ,DATA)) {
            return 0;
        }*/
        delay(500);
        sim808_send_cmd(str);
        delay(500);
        sim808_send_End_Mark();
        if(!sim808_wait_for_resp("SEND OK\r\n", DATA, DEFAULT_TIMEOUT * 10, DEFAULT_INTERCHAR_TIMEOUT * 10)) {
            return 0;
        }        
    }
    return len;
}
    

int DFRobot_SIM808::recv(char* buf, int len)
{
    sim808_clean_buffer(buf,len);
    sim808_read_buffer(buf,len);   //Ya he llamado a la funcion con la longitud del buffer - 1 y luego le estoy a甯絘diendo el 0
    return strlen(buf);
}

void DFRobot_SIM808::listen(void)
{
	 if(serialFlag)
		; //hgprsSerial->listen();
	 else
		 gprsSerial->listen();

}

bool DFRobot_SIM808::isListening(void)
{
	// if(serialFlag)
		// return hgprsSerial.isListening();
	// else
		// return gprsSerial.isListening();
}

uint32_t DFRobot_SIM808::str_to_ip(const char* str)
{
    uint32_t ip = 0;
    char* p = (char*)str;
    for(int i = 0; i < 4; i++) {
        ip |= atoi(p);
        p = strchr(p, '.');
        if (p == NULL) {
            break;
        }
        ip <<= 8;
        p++;
    }
    return ip;
}

char* DFRobot_SIM808::getIPAddress()
{
    //I have already a buffer with ip_string: snprintf(ip_string, sizeof(ip_string), "%d.%d.%d.%d", (_ip>>24)&0xff,(_ip>>16)&0xff,(_ip>>8)&0xff,_ip&0xff); 
    return ip_string;
}

unsigned long DFRobot_SIM808::getIPnumber()
{
    return _ip;
}
/* NOT USED bool DFRobot_SIM808::gethostbyname(const char* host, uint32_t* ip)
{
    uint32_t addr = str_to_ip(host);
    char buf[17];
    //snprintf(buf, sizeof(buf), "%d.%d.%d.%d", (addr>>24)&0xff, (addr>>16)&0xff, (addr>>8)&0xff, addr&0xff);
    if (strcmp(buf, host) == 0) {
        *ip = addr;
        return true;
    }
    return false;
}
*/

bool DFRobot_SIM808::getLocation(const __FlashStringHelper *apn, float *longitude, float *latitude)
{    	
	int i = 0;
    char gprsBuffer[80];
	char buffer[20];
    char *s;
    
	//send AT+SAPBR=3,1,"Contype","DFRobot_SIM808"
	sim808_check_with_cmd("AT+SAPBR=3,1,\"Contype\",\"DFRobot_SIM808\"\r","OK\r\n",CMD);
	//sen AT+SAPBR=3,1,"APN","DFRobot_SIM808_APN"
	sim808_send_cmd("AT+SAPBR=3,1,\"APN\",\"");
	if (apn) {
      sim808_send_cmd(apn);
    }
    sim808_check_with_cmd("\"\r","OK\r\n",CMD);
	//send AT+SAPBR =1,1
	sim808_check_with_cmd("AT+SAPBR=1,1\r","OK\r\n",CMD);
	
	//AT+CIPGSMLOC=1,1
	sim808_flush_serial();
	sim808_send_cmd("AT+CIPGSMLOC=1,1\r");
	sim808_clean_buffer(gprsBuffer,sizeof(gprsBuffer));	
	sim808_read_buffer(gprsBuffer,sizeof(gprsBuffer),2*DEFAULT_TIMEOUT,6*DEFAULT_INTERCHAR_TIMEOUT);
	//Serial.println(gprsBuffer);
    
	if(NULL != ( s = strstr(gprsBuffer,"+CIPGSMLOC:")))
	{
		s = strstr((char *)s, ",");
		s = s+1;
		//Serial.println(*s);
		i=0;
		while(*(++s) !=  ',')
			buffer[i++]=*s;
		buffer[i] = 0;
		*longitude = atof(buffer);
		       
		i=0;
		while(*(++s) !=  ',')
			buffer[i++]=*s;
		buffer[i] = 0;
		*latitude = atof(buffer);            
		return true;
	}
	return false;
}

bool DFRobot_SIM808::attachGPS()
{
	 if(!sim808_check_with_cmd("AT+CGNSPWR=1\r\n", "OK\r\n", CMD)) { 
        return false;
    }
	 if(!sim808_check_with_cmd("AT+CGNSTST=1\r\n", "OK\r\n", CMD)) { 
        return false;
    }
	return true;
}

bool DFRobot_SIM808::detachGPS()
{
	 if(!sim808_check_with_cmd("AT+CGNSPWR=0\r\n", "OK\r\n", CMD)) { 
        return false;
    }
	return true;
}

bool DFRobot_SIM808::getGPRMC()
{
	char c;
	static bool endflag  = false;
	static char count;
		
	while(serialSIM808->available())   //閿熸枻鎷烽敓鏂ゆ嫹閿熸枻鎷烽敓鏂ゆ嫹閿熸枻鎷�
	{	c = serialSIM808->read();
		if(endflag)
		{
			if(count--)
			{
				receivedStack[receivedStackIndex++] = c;
			}
			else{
				endflag = false;
				receivedStack[receivedStackIndex] = '\0';
				return true;
			}			
		}
		else
		{	
			switch(c)
			{
					
				case '$':									
					receivedStackIndex = 0;
					receivedStack[receivedStackIndex++] = c;								
					break;
				case '*':
					endflag = true;
					count = 2;
					receivedStack[receivedStackIndex++] = c;									
					break;
				default:
					if(receivedStackIndex < 120)
						receivedStack[receivedStackIndex++] = c;
					break;
			
			}
			return false;
		}
		return false;
	}
	return false;
}

bool DFRobot_SIM808::parseGPRMC(char *gpsbuffer)
{
	if(strstr(gpsbuffer,des) == NULL)  //閿熸枻鎷烽敓鏂ゆ嫹$GPRMC閿熻鍑ゆ嫹閿熸枻鎷烽敓鏂ゆ嫹澶撮敓鏂ゆ嫹GPS閿熸枻鎷锋伅
	{
		receivedStackIndex = 0;
		return false;
	}
	else
	{		
		if(gpsbuffer[18] == 'A')        //閿熷彨璁规嫹閿熸枻鎷烽敓鏂ゆ嫹閿熻鍑ゆ嫹閿熸枻鎷锋晥
			return true;
		else
		{
			//Serial.print("NO :");
			//Serial.println(gpsbuffer[18]);
			return false;
		}
			
	}
		
}

// Parse a (potentially negative) number with up to 2 decimal digits -xxxx.yy
int32_t DFRobot_SIM808::parseDecimal(const char *term)
{
  bool negative = *term == '-';
  if (negative) ++term;
  int32_t ret = 100 * (int32_t)atol(term);
  while (isdigit(*term)) ++term;
  if (*term == '.' && isdigit(term[1]))
  {
    ret += 10 * (term[1] - '0');
    if (isdigit(term[2]))
      ret += term[2] - '0';
  }
  return negative ? -ret : ret;
}

 void DFRobot_SIM808::getTime(uint32_t time){
	 GPSdata.hour     =  time / 1000000;
	 GPSdata.minute  = (time / 10000) % 100;
	 GPSdata.second = (time / 100) % 100;
	 GPSdata.centisecond =  time % 100;
 }

 
  void DFRobot_SIM808::getDate(uint32_t date){
	 uint16_t year = date % 100;
	 GPSdata. year    =  year + 2000;	 
	 GPSdata.month  = (date / 100) % 100;
	 GPSdata.day = date / 10000;
 }
 
 
bool DFRobot_SIM808::getGPS() 
{
	 if(!getGPRMC())    //没有得到$GPRMC字符串开头的GPS信息
		 return false;
	// Serial.println(receivedStack);
	 if(!parseGPRMC(receivedStack))  //不是$GPRMC字符串开头的GPS信息
		 return false;  
		
	// skip mode
    char *tok = strtok(receivedStack, ",");     //起始引导符
    if (! tok) return false;

   // grab time                                  //<1> UTC时间，格式为hhmmss.sss；
   // tok = strtok(NULL, ",");
	char *time = strtok(NULL, ",");
    if (! time) return false;
	uint32_t newTime = (uint32_t)parseDecimal(time);
	getTime(newTime);

    // skip fix
    tok = strtok(NULL, ",");              //<2> 定位状态，A=有效定位，V=无效定位
    if (! tok) return false;

    // grab the latitude
    char *latp = strtok(NULL, ",");       //<3> 纬度ddmm.mmmm(度分)格式(前面的0也将被传输)
    if (! latp) return false;

    // grab latitude direction              // <4> 纬度半球N(北半球)或S(南半球)
    char *latdir = strtok(NULL, ",");
    if (! latdir) return false;

    // grab longitude                       //<5> 经度dddmm.mmmm(度分)格式(前面的0也将被传输)
    char *longp = strtok(NULL, ",");
    if (! longp) return false;

    // grab longitude direction            //<6> 经度半球E(东经)或W(西经)
    char *longdir = strtok(NULL, ",");
    if (! longdir) return false;

    float latitude = atof(latp);
    float longitude = atof(longp);

	GPSdata.lat = latitude/100;

    // convert longitude from minutes to decimal  
	GPSdata.lon= longitude/100;

    // only grab speed if needed                  //<7> 地面速率(000.0~999.9节，前面的0也将被传输)
   // if (speed_kph != NULL) {

      // grab the speed in knots
      char *speedp = strtok(NULL, ",");
      if (! speedp) return false;

      // convert to kph
      //*speed_kph = atof(speedp) * 1.852;
	  GPSdata.speed_kph= atof(speedp) * 1.852;

   // }

    // only grab heading if needed             
   // if (heading != NULL) {

      // grab the speed in knots
      char *coursep = strtok(NULL, ",");
      if (! coursep) return false;

      //*heading = atof(coursep);
		GPSdata.heading = atof(coursep);
   // }
	
	// grab date
	char *date = strtok(NULL, ",");   
    if (! date) return false;
	uint32_t newDate = atol(date);
	getDate(newDate);

    // no need to continue
   // if (altitude == NULL){
   //   return true;
	//}
	return true;
}

void DFRobot_SIM808::latitudeConverToDMS()
{
    float temp;
    latDMS.degrees = (int)GPSdata.lat; 
    temp = (GPSdata.lat - latDMS.degrees)*60;
    latDMS.minutes = (int)temp;
    latDMS.seconeds = (temp - latDMS.minutes)*60;
}

void DFRobot_SIM808::LongitudeConverToDMS()
{
    float temp;
    longDMS.degrees = (int)GPSdata.lon; 
    temp = (GPSdata.lon - longDMS.degrees)*60;
    longDMS.minutes = (int)temp;
    longDMS.seconeds = (temp - longDMS.minutes)*60;
}