Erwan's Blog

Last ESP8266 example for the day (credit goes here) : a web server turning a lef off and on.

#include 
 
const char* ssid = "livebox0";
const char* password = "password";
 
int ledPin = 2; // GPIO2
WiFiServer server(80);
 
void setup() {
  Serial.begin(115200);
  delay(10);
 
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
 
  // Connect to WiFi network
  Serial.println();
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
 
  WiFi.begin(ssid, password);
 
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected");
 
  // Start the server
  server.begin();
  Serial.println("Server started");
 
  // Print the IP address
  Serial.print("Use this URL to connect: ");
  Serial.print("http://");
  Serial.print(WiFi.localIP());
  Serial.println("/");
 
}
 
void loop() {
  // Check if a client has connected
  WiFiClient client = server.available();
  if (!client) {
    return;
  }
 
  // Wait until the client sends some data
  Serial.println("new client");
  while(!client.available()){
    delay(1);
  }
 
  // Read the first line of the request
  String request = client.readStringUntil('\r');
  Serial.println(request);
  client.flush();
 
  // Match the request
 
  int value = LOW;
  if (request.indexOf("/LED=ON") != -1)  {
    digitalWrite(ledPin, HIGH);
    value = HIGH;
  }
  if (request.indexOf("/LED=OFF") != -1)  {
    digitalWrite(ledPin, LOW);
    value = LOW;
  }
 
// Set ledPin according to the request
//digitalWrite(ledPin, value);
 
  // Return the response
  client.println("HTTP/1.1 200 OK");
  client.println("Content-Type: text/html");
  client.println(""); //  do not forget this one
  client.println("");
  client.println("");
 
  client.print("Led pin is now: ");
 
  if(value == HIGH) {
    client.print("On");
  } else {
    client.print("Off");
  }
  client.println("

");
  client.println("Click here turn the LED on pin 2 ON
");
  client.println("Click here turn the LED on pin 2 OFF
");
  client.println("");
 
  delay(1);
  Serial.println("Client disonnected");
  Serial.println("");
 
}

In a previous article, we saw how I flashed my new ESP8266.

Now lets see how to « talk » with this module.

First wiring : chpd high, 3v3+gnd, tx to rx / rx to tx.

Lets launch putty,
select serial,
enter the right com port (com7 for me, using my usb to serial adapter),
select 9600 bauds (if it does not work, try 57600 or 115200).

Lets try the below command (ctrl/m + ctrl/j to enter):
-AT should respond OK
-AT+GMR should to get the firmware revision
-AT+CWMODE=3 to select AP & STA mode
-AT+CWLAP to list access points
-AT+CWJAP=“SSID”,“password” to connect to an AP
-AT+CIFSR to retrieve the ip (at this point you should be able to ping the module on your home wifi network)

Just received my esp2866.
Read more about it here.
In short it is a wireless soc which you can control from a MCU (like Arduino) thru serial OR use directly as MCU (from Arduino IDE).

First things first : lets flash it with the latest firmware.

1-get the firmware here.
2-get the flasher here.
3-wire 3v3 and ground.
4-wire tx to rx, and rx to tx (I use a usb to serial ftdi adapter)
5-set gpio0 to low (ground)
6-reboot (power off/on will do)
7-flash
8-set gpio0 free
9-reboot and enjoy