main.cpp

00001 #include "mbed.h"
00002 #include "ESP8266.h"                            //Include header file from Author: Antonio Quevedo
00003 #include "hcsr04.h"
00004 
00005 #define APIKEY E21WSWLRUWTIDWNX                 //Put "Write key" of your channel in thingspeak.com 
00006 #define IP "184.106.153.149"                    //IP Address of "api.thingspeak.com\"
00007 #define WIFI_SSID "some-ssid"
00008 #define WIFI_PASS "some-passwd"
00009 
00010 Serial pc(USBTX,USBRX);
00011 ESP8266 esp(D1, D0, 115200);                    //baud rate for wifi
00012 HCSR04  usensor(A4, A5);                        //Trigger, Echo
00013 
00014 char snd[255],rcv[1000],snd_Data[255];          //snd= string used to send command to ESP 8266 wii and  rcv = string used to receive response from ESP8266 wifi module 
00015 
00016 void esp_initialize(void);                      //Function used to initialize ESP8266 wifi module 
00017 void esp_send(char);                            //Function used to connect with thingspeak.com and update channel using ESP8266 wifi module 
00018 
00019 int ping()
00020 {
00021     usensor.start();
00022     wait_ms(500);
00023     return(usensor.get_dist_cm());
00024 }
00025 
00026 int main() 
00027 {    
00028     pc.baud(115200);                            //Baud rate used for communicating with Tera-term on PC
00029     
00030     pc.printf("START\r\n");                     //Starting point
00031     esp_initialize();
00032     
00033     int distance;
00034     char cd;
00035 
00036     while (1) 
00037     {   
00038         distance = ping();                      //ping function
00039         pc.printf("\n distance = %ld cm",distance);
00040         wait_ms(10000);
00041         if(distance<=30)
00042         {
00043             cd = 'd';
00044             esp_send(cd);
00045         }
00046         else
00047         {
00048             cd = 'a';
00049             esp_send(cd);
00050         }
00051     }
00052 }
00053 
00054 void esp_initialize(void)
00055 {    
00056     pc.printf("Initializing ESP\r\n"); 
00057       
00058     pc.printf("Reset ESP\r\n"); 
00059     esp.Reset();                                //RESET ESP
00060     esp.RcvReply(rcv, 400);                     //receive a response from ESP
00061     //pc.printf(rcv);                           //Print the response onscreen 
00062     wait(2);
00063     
00064     strcpy(snd,"AT");
00065     esp.SendCMD(snd);
00066     pc.printf(snd);
00067     //wait(2);
00068     esp.RcvReply(rcv, 400);       
00069     pc.printf(rcv);      
00070     wait(0.1);
00071     
00072     strcpy(snd,"AT+CWMODE=1");
00073     esp.SendCMD(snd);
00074     pc.printf(snd);
00075     wait(2);
00076 
00077     strcpy(snd,"AT+CWJAP=\"");
00078     strcat(snd,WIFI_SSID);
00079     strcat(snd,"\",\"");
00080     strcat(snd,WIFI_PASS);
00081     strcat(snd,"\"");
00082     
00083     esp.SendCMD(snd);
00084     pc.printf(snd);
00085     wait(5);
00086     esp.RcvReply(rcv, 400);       
00087     pc.printf("\n %s \n", rcv); 
00088     
00089     strcpy(snd,"AT+CIPMUX=0");
00090     esp.SendCMD(snd);
00091     pc.printf(snd);
00092     //wait(2);
00093     esp.RcvReply(rcv, 400);       
00094     pc.printf("\n %s \n", rcv); 
00095 }
00096 
00097 void esp_send(char ch)
00098 {
00099     //ESP updates the Status of Thingspeak channel//
00100     strcpy(snd,"AT+CIPSTART=");
00101     strcat(snd,"\"TCP\",\"");
00102     strcat(snd,IP);
00103     strcat(snd,"\",80");
00104     
00105     esp.SendCMD(snd); 
00106     pc.printf("S\r\n%s",snd);
00107     //wait(2);                                                    
00108     esp.RcvReply(rcv, 1000);
00109     pc.printf("R\r\n%s",rcv);
00110     wait(1);
00111     
00112     sprintf(snd,"GET https://api.thingspeak.com/update?api_key=E21WSWLRUWTIDWNX&field1=%c\n",ch);
00113     
00114     int i=0;
00115     for(i=0;snd[i]!='\0';i++);
00116     i++;
00117     char cmd[255];
00118     
00119     sprintf(cmd,"AT+CIPSEND=%d",i);             //Send Number of open connection and Characters to send 
00120     esp.SendCMD(cmd);
00121     pc.printf("S\r\n%s",cmd);
00122     while(i<=20 || rcv == ">")
00123     {
00124         esp.RcvReply(rcv, 1000);
00125         wait(100);
00126         i++;
00127     }
00128     pc.printf("R\r\n%s",rcv);
00129     esp.SendCMD(snd);                           //Post value to thingspeak channel
00130     pc.printf("S\r\n%s",snd);
00131     while(i<=20 || rcv == "OK")
00132     {
00133         esp.RcvReply(rcv, 1000);
00134         wait(100);
00135         i++;
00136     }
00137     pc.printf("R\r\n%s",rcv);
00138 }