/* ====== ESP8266 Demo ======
* Print out analog values
* (Updated Dec 14, 2014)
* ==========================
*
* Change SSID and PASS to match your WiFi settings.
* The IP address is displayed to soft serial upon successful connection.
*
* Ray Wang @ Rayshobby LLC
* [URL]http://rayshobby.net/?p=9734[/URL] */
// comment this part out if not using LCD debug
#define BUFFER_SIZE 512
#define SSID "your_ssid" // change this to match your WiFi SSID
#define PASS "your_password" // change this to match your WiFi password
#define PORT "8080" // using port 8080 by default
char buffer[BUFFER_SIZE];
/*
// If using Software Serial for debug
// Use the definitions below
//#include <SoftwareSerial.h>
//SoftwareSerial dbg(7,8); // use pins 7, 8 for software serial
//#define esp Serial
*/
// If your MCU has dual USARTs (e.g. ATmega644)
// Use the definitions below
#define dbg Serial // use Serial for debug
#define esp Serial1 // use Serial1 to talk to esp8266
// By default we are looking for OKrn
char OKrn[] = "OKrn";
byte wait_for_esp_response(int timeout, char* term=OKrn) {
unsigned long t=millis();
bool found=false;
int i=0;
int len=strlen(term);
// wait for at most timeout milliseconds
// or if OKrn is found
while(millis()<t+timeout) {
if(esp.available()) {
buffer[i++]=esp.read();
if(i>=len) {
if(strncmp(buffer+i-len, term, len)==0) {
found=true;
break;
}
}
}
}
buffer[i]=0;
dbg.print(buffer);
return found;
}
void setup() {
// assume esp8266 operates at 115200 baud rate
// change if necessary to match your modules' baud rate
esp.begin(115200);
dbg.begin(9600);
dbg.println("begin.");
setupWiFi();
// print device IP address
dbg.print("device ip addr:");
esp.println("AT+CIFSR");
wait_for_esp_response(1000);
}
bool read_till_eol() {
static int i=0;
if(esp.available()) {
buffer[i++]=esp.read();
if(i==BUFFER_SIZE) i=0;
if(i>1 && buffer[i-2]==13 && buffer[i-1]==10) {
buffer[i]=0;
i=0;
dbg.print(buffer);
return true;
}
}
return false;
}
void loop() {
int ch_id, packet_len;
char *pb;
if(read_till_eol()) {
if(strncmp(buffer, "+IPD,", 5)==0) {
// request: +IPD,ch,len:data
sscanf(buffer+5, "%d,%d", &ch_id, &packet_len);
if (packet_len > 0) {
// read serial until packet_len character received
// start from :
pb = buffer+5;
while(*pb!=':') pb++;
pb++;
if (strncmp(pb, "GET /", 5) == 0) {
wait_for_esp_response(1000);
dbg.println("-> serve homepage");
serve_homepage(ch_id);
}
}
}
}
}
void serve_homepage(int ch_id) {
String header = "HTTP/1.1 200 OKrnContent-Type: text/htmlrnConnection: closernRefresh: 5rn";
String content="";
// output the value of each analog input pin
for (int analogChannel = 0; analogChannel < 6; analogChannel++) {
int sensorReading = analogRead(analogChannel);
content += "analog input ";
content += analogChannel;
content += " is ";
content += sensorReading;
content += "<br />n";
}
header += "Content-Length:";
header += (int)(content.length());
header += "rnrn";
esp.print("AT+CIPSEND=");
esp.print(ch_id);
esp.print(",");
esp.println(header.length()+content.length());
if(wait_for_esp_response(2000, "> ")) {
esp.print(header);
esp.print(content);
} else {
esp.print("AT+CIPCLOSE=");
esp.println(ch_id);
}
}
void setupWiFi() {
// try empty AT command
esp.println("AT");
wait_for_esp_response(1000);
// set mode 1 (client)
esp.println("AT+CWMODE=1");
wait_for_esp_response(1000);
// reset WiFi module
esp.print("AT+RSTrn");
wait_for_esp_response(1500);
delay(3000);
// join AP
esp.print("AT+CWJAP="");
esp.print(SSID);
esp.print("","");
esp.print(PASS);
esp.println(""");
// this may take a while, so wait for 5 seconds
wait_for_esp_response(5000);
esp.println("AT+CIPSTO=30");
wait_for_esp_response(1000);
// start server
esp.println("AT+CIPMUX=1");
wait_for_esp_response(1000);
esp.print("AT+CIPSERVER=1,"); // turn on TCP service
esp.println(PORT);
wait_for_esp_response(1000);
}
