April 2017 –

電子工作で離れた場所からコントロールしたいとき、どうしてもWiFiが欲しくなります。
ArduinoのWiFiシールドを探していたところ、このようなモジュールがあることを知りましたが、なんとこれだけでArduinoIDEが使えるようです。
サンプルプロジェクトにあるWebサーバを使って、ブラウザからオンボードのLEDをon/offするテストをしてみました。

/*
 *  This sketch demonstrates how to set up a simple HTTP-like server.
 *  The server will set a GPIO pin depending on the request
 *    http://server_ip/gpio/0 will set the GPIO2 low,
 *    http://server_ip/gpio/1 will set the GPIO2 high
 *  server_ip is the IP address of the ESP8266 module, will be 
 *  printed to Serial when the module is connected.
 */

#include <ESP8266WiFi.h>

const char* ssid = "ssid";
const char* password = "password";

// Create an instance of the server
// specify the port to listen on as an argument
WiFiServer server(80);

void setup() {
  Serial.begin(115200);
  delay(10);

  // prepare GPIO2
  pinMode(2, OUTPUT);
  digitalWrite(2, 0);
  
  // 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.println(WiFi.localIP());
}

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 req = client.readStringUntil('\r');
  Serial.println(req);
  client.flush();
  
  // Match the request
  int val;
  if (req.indexOf("/gpio/0") != -1)
    val = 0;
  else if (req.indexOf("/gpio/1") != -1)
    val = 1;
  else {
    Serial.println("invalid request");
    client.stop();
    return;
  }

  // Set GPIO2 according to the request
  digitalWrite(2, val);
  
  client.flush();

  // Prepare the response
  String s = "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n\r\n<!DOCTYPE HTML>\r\n<html>\r\nGPIO is now ";
  s += (val)?"high":"low";
  s += "</html>\n";

  // Send the response to the client
  client.print(s);
  delay(1);
  Serial.println("Client disonnected");

  // The client will actually be disconnected 
  // when the function returns and 'client' object is detroyed
}

* This sketch demonstrates how to set up a simple HTTP-like server.

* The server will set a GPIO pin depending on the request

* http://server_ip/gpio/0 will set the GPIO2 low,

* http://server_ip/gpio/1 will set the GPIO2 high

* server_ip is the IP address of the ESP8266 module, will be

* printed to Serial when the module is connected.

#include <ESP8266WiFi.h>

const char* ssid = "ssid";

const char* password = "password";

// Create an instance of the server

// specify the port to listen on as an argument

WiFiServer server(80);

void setup() {

Serial.begin(115200);

delay(10);

// prepare GPIO2

pinMode(2, OUTPUT);

digitalWrite(2, 0);

// Connect to WiFi network

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.println(WiFi.localIP());

}

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 req = client.readStringUntil('\r');

Serial.println(req);

client.flush();

// Match the request

int val;

if (req.indexOf("/gpio/0") != -1)

val = 0;

else if (req.indexOf("/gpio/1") != -1)

val = 1;

else {

Serial.println("invalid request");

client.stop();

return;

}

// Set GPIO2 according to the request

digitalWrite(2, val);

client.flush();

// Prepare the response

String s = "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n\r\n<!DOCTYPE HTML>\r\n<html>\r\nGPIO is now ";

s += (val)?"high":"low";

s += "</html>\n";

// Send the response to the client

client.print(s);

delay(1);

Serial.println("Client disonnected");

// The client will actually be disconnected

// when the function returns and 'client' object is detroyed

}

書き込み

設定

ブラウザからアクセス

シリアルモニタ

逆ですが、LowでLEDが光ります。
ライブラリのインストールには、
http://arduino.esp8266.com/versions/2.3.0/package_esp8266com_index.json
を環境設定のAdditional Boards Manager URLsに設定します。
(設定したのがしばらく前で参照元をわすれました^^;)

ArduinoIDEは、いろいろとそろっていて便利です。

_bitlife

MECHA & EMBEDDED

Month: April 2017

ESP8266 WiFi