ESPAT.cpp

00001 #include "ESPAT.h"
00002 #include "mbed.h"
00003 #include "string"
00004 
00005 /*
00006 Library for using an ESP8266 (e.g. ESP-01 board) with its AT command firmware as webserver
00007 Version: 1.0.0
00008 (C)2019 Elias Nestl
00009 */
00010 
00011 ESPAT::ESPAT(PinName tx, PinName rx, int baud) : espSerial(tx, rx, baud) {
00012 }
00013 
00014 //Serial pc(USBTX, USBRX, 115200);
00015 
00016 void ESPAT::readStrUntil(string * str, char until) {
00017     while (true) {
00018         char c = espSerial.getc();
00019         if (c != until) {
00020             *str += c;
00021         } else {
00022             break;
00023         }
00024     }
00025 }
00026 
00027 void ESPAT::waitFor(char * text) {
00028     //string s;
00029     for (int i = 0; i < strlen(text); i++) {
00030         char c = espSerial.getc();
00031         //s += c;
00032         if (c != text[i]) {
00033             i = 0;
00034         }
00035     }
00036     //pc.printf("%s", s.c_str());
00037 }
00038 
00039 void ESPAT::sendCommand(char * cmd, bool waitOk) {
00040     //pc.printf("%s\r\n", cmd);
00041     espSerial.printf("%s\r\n", cmd);
00042     if (waitOk) waitFor("OK");
00043 }
00044 
00045 void ESPAT::resetEsp() {
00046     sendCommand("AT+RST");
00047     waitFor("ready");
00048 }
00049 
00050 void ESPAT::initWifiStation(string ssid, string pwd) {
00051     sendCommand("AT+CWMODE_CUR=1");
00052     string wifiCmd = "AT+CWJAP_CUR=\"" + ssid + "\",\"" + pwd + "\"";
00053     sendCommand((char*) wifiCmd.c_str());
00054 }
00055 
00056 void ESPAT::initWifiAP(string ssid, string pwd, string channel, string encryption) {
00057     sendCommand("AT+CWMODE_CUR=2");
00058     string wifiCmd = "AT+CWSAP_CUR=\"" + ssid + "\",\"" + pwd + "\"," + channel + "," + encryption;
00059     sendCommand((char*) wifiCmd.c_str());
00060 }
00061 
00062 void ESPAT::initServer(void (*requestHandler)(int, string)) {
00063     sendCommand("AT+CIPMUX=1");
00064     sendCommand("AT+CIPSERVER=1,80");
00065     while (true) {
00066         // Input looks like this: +IPD,0,372:GET / HTTP/1.1
00067         waitFor("+IPD,");
00068         // Parse linkId
00069         int linkId = 0;
00070         char c;
00071         while (true) {
00072             c = espSerial.getc();
00073             if (c == ',') break;
00074             linkId = linkId * 10 + (c - '0');
00075         }
00076         // Parse path
00077         waitFor(":GET ");
00078         string path;
00079         readStrUntil(&path, ' ');
00080         // Send request to handler
00081         requestHandler(linkId, path);
00082     }
00083 }
00084 
00085 void ESPAT::tcpReply(int linkId, string data) {
00086     espSerial.printf("AT+CIPSEND=%d,%d\r\n", linkId, data.length());
00087     wait(0.1); // Can't use waitFor here as it isn't fast enough
00088     for (int i = 0; i < data.length(); i++) {
00089         // Artificially slowing down this to prevent errors
00090         espSerial.printf("%c", data[i]);
00091     }
00092     waitFor("SEND OK");
00093     espSerial.printf("AT+CIPCLOSE=%d\r\n", linkId);
00094     waitFor("OK");
00095 }
00096 
00097 void ESPAT::httpReply(int linkId, string code, string payload) {
00098     string data = "HTTP/1.1 " + code + "\r\nContent-Type: text/html\r\n\r\n" + payload;
00099     tcpReply(linkId, data);
00100 }