main.cpp

00001 /************************************************************************
00002  * Program  : ESP8266_HTTP_MQTT_Server from _Arduino_Esp_Comm
00003  * Descr.   : M3-ESP8266-Communication similar to Arduino communication
00004  * Input    : Get data from Esp8266 from serial
00005  *            Process data (i.e. digital and analog channels)
00006               ToDo: apply diffrent sensors over I2C, SPI, ...(i.e. LM75,...)
00007  * Output   : replay to Esp8266 over serial
00008  ************************************************************************/
00009 
00010 #include "mbed.h"
00011 #include <stdio.h>
00012 #include <string>
00013 
00014 DigitalOut  LedD1(LED1);
00015 DigitalOut  LedD2(LED2);
00016 DigitalOut  LedD3(LED3);
00017 DigitalOut  LedD4(LED4);
00018 BusOut ledbus(LED1, LED2, LED3, LED4);
00019 AnalogIn poti1(p19);
00020 AnalogIn poti2(p20);
00021 
00022 Serial wifi(p9, p10);       // M0, M3, (P1_0, P0_20) Bertl
00023 Serial pc(USBTX, USBRX);
00024 char recChar=0;
00025 bool recFlag=false;
00026 
00027 string fromEsp8266 = "";
00028 string toEsp8266 = "";
00029 string periodicMsg="";
00030 long lastMsg = 0;
00031 int url_decode(char *encoded_str, char *decoded_str);
00032 
00033 string getPoti(char potiNo)
00034 {
00035     char pValStr[20] = "ME-01";
00036     int n=-1;
00037     // pc.printf("Poti %c selected\r\n", potiNo);
00038     if (potiNo == 1)
00039         n = sprintf(pValStr, "%d", poti1.read_u16());
00040     else if (potiNo == 2)
00041         n = sprintf(pValStr, "%d", poti2.read_u16());
00042     if (n<=0)
00043         sprintf(pValStr, "ME01");
00044 
00045     pc.printf("Wert von Poti %c: %s\r\n", potiNo, pValStr);
00046     return pValStr;
00047 }
00048 
00049 /********************************************************
00050  *  Process Requests from ESP8266
00051  *  Input: global string fromEsp8266
00052  ********************************************************/
00053 void ProcessRequests()
00054 {
00055     int chan,state,button;
00056     float Ain;
00057     char szAin[20],szT[200];
00058     string poti;
00059 
00060     // process string if end of line
00061     if(fromEsp8266.substr(0,8)=="Arduino_") {   // Valid command from ESP8266?
00062         if(fromEsp8266.substr(8,2) == "SM") {  // Set Digital if true
00063             // --- Build Reply String -----------------------------------------------
00064             toEsp8266 = "Echoing your message: ";
00065             toEsp8266 += fromEsp8266.substr(10,50);
00066             wifi.printf("%s\n", toEsp8266);
00067             // ---- Set Periodic Message String -------------------------------------
00068             url_decode((char *)toEsp8266.c_str(), (char *)szT );
00069             periodicMsg = szT;
00070         } else if(fromEsp8266.substr(8,2) == "SD") { // Set Digital if true
00071             // --- Build Reply String -----------------------------------------------
00072             toEsp8266 = "Digital Channel ";
00073             toEsp8266 += fromEsp8266.substr(10,2); //Digital Channel
00074             toEsp8266 += " is ";
00075             toEsp8266 += (fromEsp8266.substr(12,1)=="0") ? "LO" : "HI";
00076             // ---- Send Reply String -----------------------------------------------
00077             wifi.printf("%s\n", toEsp8266);             // Send Reply String to Console
00078             // --- Set Digital Channel State ----------------------------------------
00079             chan = atoi(fromEsp8266.substr(10,2).c_str());
00080             state = atoi(fromEsp8266.substr(12,1).c_str());
00081             ledbus[chan-1] = state;                     // Set Digital Output per request
00082 
00083         } else if(fromEsp8266.substr(8,2) == "GD") {    // Get Digital if true
00084             // --- Get Digital Channel State ----------------------------------------
00085             chan = atoi(fromEsp8266.substr(10,2).c_str());
00086             state = LedD4.read();             // Set Digital Output per request
00087             // --- Build Reply String -----------------------------------------------
00088             toEsp8266 = "Digital Channel ";
00089             toEsp8266 += fromEsp8266.substr(10,2);      // Digital Channel
00090             toEsp8266 += " is ";
00091             toEsp8266 += (state==0) ? "LO" : "HI";
00092             // ---- Send Reply String -----------------------------------------------
00093             wifi.printf("%s\n",toEsp8266);              // Send Reply String to ESP
00094         } else if(fromEsp8266.substr(8,2) == "GA") {    // Get Analog if true
00095             // --- Get Analog Channel Reading ---------------------------------------
00096             chan = atoi(fromEsp8266.substr(10,2).c_str());
00097             //Ain = 0.0048828 * (float) analogRead(chan);        // Read analog input
00098             //ftoa(Ain,szAin, 2);
00099             poti = getPoti(chan);
00100             // --- Build Reply String -----------------------------------------------
00101             toEsp8266 = "Poti ";
00102             toEsp8266 += fromEsp8266.substr(10,2); //Analog Channel
00103             toEsp8266 += " is ";
00104             toEsp8266 += poti; //string(szAin);
00105             // ---- Send Reply String -----------------------------------------------
00106             wifi.printf("%s\n",toEsp8266);             // Send Reply String to ESP
00107         } else {
00108             // ---- Send Reply String -----------------------------------------------
00109             toEsp8266 = "Arduino does not recognize request.";
00110             //pc.printf("%s\n", toEsp8266);             // Send Reply String to Console
00111             wifi.printf("%s\n", toEsp8266);             // Send Reply String to ESP
00112         }
00113     }
00114     fromEsp8266 = "";
00115     //toEspSerial.flush();
00116 }
00117 
00118 /********************************************************
00119  *  URL Message Decoder
00120  ********************************************************/
00121 int url_decode(char *encoded_str, char *decoded_str)
00122 {
00123     // While we're not at the end of the string (current character not NULL)
00124     while (*encoded_str) {
00125         // Check to see if the current character is a %
00126         if (*encoded_str == '%') {
00127 
00128             // Grab the next two characters and move encoded_str forwards
00129             encoded_str++;
00130             char high = *encoded_str;
00131             encoded_str++;
00132             char low = *encoded_str;
00133 
00134             // Convert ASCII 0-9A-F to a value 0-15
00135             if (high > 0x39) high -= 7;
00136             high &= 0x0f;
00137 
00138             // Same again for the low byte:
00139             if (low > 0x39) low -= 7;
00140             low &= 0x0f;
00141 
00142             // Combine the two into a single byte and store in decoded_str:
00143             *decoded_str = (high << 4) | low;
00144         } else {
00145             // All other characters copy verbatim
00146             *decoded_str = *encoded_str;
00147         }
00148 
00149         // Move both pointers to the next character:
00150         encoded_str++;
00151         decoded_str++;
00152     }
00153     // Terminate the new string with a NULL character to trim it off
00154     *decoded_str = 0;
00155     return 0;
00156 }
00157 
00158 void flushSerialBuffer()
00159 {
00160     while (wifi.readable()) {
00161         wifi.getc();
00162     }
00163 }
00164 
00165 /********************************************************
00166  *  ISR readData and stored in global fromEsp8266 string
00167  ********************************************************/
00168 bool semi = false;
00169 bool blank = false;
00170 
00171 void readData()
00172 {
00173     recChar = wifi.getc();
00174     if (recChar != '\n') {
00175         if(recChar != ':') semi = true;
00176         if(semi && (recChar != ' ')) blank = true;
00177         if(semi && blank)
00178             fromEsp8266 += recChar;                        // add it to receive string
00179     } else {
00180         recFlag = true;
00181         semi = false;
00182         blank = false;
00183         flushSerialBuffer();
00184     }
00185 }
00186 
00187 int main()
00188 {
00189     pc.baud(115200);
00190     wifi.baud(115200);
00191     pc.printf("\f\n\r-------------ESP8266 Arduino -------------\n\r");
00192     wifi.attach(&readData);
00193     while(1) {
00194         if(recFlag) {
00195             pc.printf("readData: %s\n", fromEsp8266);
00196             ProcessRequests();
00197             recFlag=false;
00198         }
00199         LedD1 = 1;
00200         wait(0.2);
00201         LedD1 = 0;
00202         wait(0.2);
00203     }
00204 }