# Arduino UNO R4 Wi-FiでWi-Fi通信

# ひとまず Arduino UNO R4 Wi-Fiを使えるようにする

::: success
Raspberry Pi にArduino IDEをインストールすれば，Raspberry PiからArduino UNO R4 Wi-Fiをコーディングできます．Raspberry Pi 5はARMコアの64bitなので，Arduino IDEはレガシー版(1.8)を使ってください．
:::

:::info
ボードマネージャでArduino UNO R4のボードをインストールして下さい．
:::

## あとは以下のスケッチを実行

#include "Arduino_LED_Matrix.h"
#define LOOPSIZE 12

ArduinoLEDMatrix matrix;

void setup() {
  Serial.begin(96000);
  matrix.begin();
}

const uint32_t CIST_logo[][4] = {
  {
    0x100f010,
    0x82006fe3,
    0x103204c0,
    66
  },
  {
    0x807808,
    0x410037f1,
    0x88190260,
    66
  },
  {
    0x403c04,
    0x20809bf0,
    0xc40c8130,
    66
  },
  {
    0x201e02,
    0x1040cdf0,
    0x62064098,
    66
  },
  {
    0x100f81,
    0x20e6f0,
    0x3103204c,
    66
  },
  {
    0x80080740,
    0x8010f378,
    0x18019026,
    66
  },
  {
    0x400c0320,
    0x4008f9b4,
    0xc80c013,
    66
  },
  {
    0x200e0110,
    0x2004fcd2,
    0x6406809,
    66
  },
  {
    0x100f0008,
    0x1002fe61,
    0x3203c04,
    66
  },
  {
    0x8078084,
    0x17f30,
    0x81901602,
    66
  },
  {
    0x403c042,
    0x800bf9c,
    0x40c80301,
    66
  },
  {
    0x201e021,
    0x400dfc6,
    0x20640980,
    66
  }
};

void loop(){
  for(int i=0;i<LOOPSIZE;i++){
    matrix.loadFrame(CIST_logo[i]);
    delay(CIST_logo[i][3]);
    }
}

何が出るかな．


LEDマトリクスの黄色部分の32bitのHEX表記
LEDマトリクスの水色部分の32bitのHEX表記
LEDマトリクスの緑色部分の32bitのHEX表記

の順で並んでいます．

https://ledmatrix-editor.arduino.cc/

で描画し，右上の`</>`マークを押すとダウンロードできます．

# Wi-Fi

#define SECRET_SSID "HSP"
#define SECRET_PASS "2025oc0802"

#include "WiFiS3.h"
//#include "arduino_secrets.h" 
///////please enter your sensitive data in the Secret tab/arduino_secrets.h
char ssid[] = SECRET_SSID;        // your network SSID (name)
char pass[] = SECRET_PASS;    // your network password (use for WPA, or use as key for WEP)
int keyIndex = 0;                 // your network key index number (needed only for WEP)

int led =  LED_BUILTIN;
int status = WL_IDLE_STATUS;
WiFiServer server(80);

void setup() {
  Serial.begin(9600);      // initialize serial communication
  pinMode(led, OUTPUT);      // set the LED pin mode

  // check for the WiFi module:
  if (WiFi.status() == WL_NO_MODULE) {
    Serial.println("Communication with WiFi module failed!");
    // don't continue
    while (true);
  }

  String fv = WiFi.firmwareVersion();
  if (fv < WIFI_FIRMWARE_LATEST_VERSION) {
    Serial.println("Please upgrade the firmware");
  }

  // attempt to connect to WiFi network:
  while (status != WL_CONNECTED) {
    Serial.print("Attempting to connect to Network named: ");
    Serial.println(ssid);                   // print the network name (SSID);

    // Connect to WPA/WPA2 network. Change this line if using open or WEP network:
    status = WiFi.begin(ssid, pass);
    // wait 10 seconds for connection:
    delay(10000);
  }
  server.begin();                           // start the web server on port 80
  printWifiStatus();                        // you're connected now, so print out the status
}


void loop() {
  WiFiClient client = server.available();   // listen for incoming clients

  if (client) {                             // if you get a client,
    Serial.println("new client");           // print a message out the serial port
    String currentLine = "";                // make a String to hold incoming data from the client
    while (client.connected()) {            // loop while the client's connected
      if (client.available()) {             // if there's bytes to read from the client,
        char c = client.read();             // read a byte, then
        Serial.write(c);                    // print it out to the serial monitor
        if (c == '\n') {                    // if the byte is a newline character

          // if the current line is blank, you got two newline characters in a row.
          // that's the end of the client HTTP request, so send a response:
          if (currentLine.length() == 0) {
            // HTTP headers always start with a response code (e.g. HTTP/1.1 200 OK)
            // and a content-type so the client knows what's coming, then a blank line:
            client.println("HTTP/1.1 200 OK");
            client.println("Content-type:text/html");
            client.println();

            // the content of the HTTP response follows the header:
            client.print("<p style=\"font-size:7vw;\">Click <a href=\"/H\">here</a> turn the LED on<br></p>");
            client.print("<p style=\"font-size:7vw;\">Click <a href=\"/L\">here</a> turn the LED off<br></p>");
            
            // The HTTP response ends with another blank line:
            client.println();
            // break out of the while loop:
            break;
          } else {    // if you got a newline, then clear currentLine:
            currentLine = "";
          }
        } else if (c != '\r') {  // if you got anything else but a carriage return character,
          currentLine += c;      // add it to the end of the currentLine
        }

        // Check to see if the client request was "GET /H" or "GET /L":
        if (currentLine.endsWith("GET /H")) {
          digitalWrite(LED_BUILTIN, HIGH);               // GET /H turns the LED on
        }
        if (currentLine.endsWith("GET /L")) {
          digitalWrite(LED_BUILTIN, LOW);                // GET /L turns the LED off
        }
      }
      
    }
    // close the connection:
    client.stop();
    Serial.println("client disconnected");
  }
}

void printWifiStatus() {
  // print the SSID of the network you're attached to:
  Serial.print("SSID: ");
  Serial.println(WiFi.SSID());

  // print your board's IP address:
  IPAddress ip = WiFi.localIP();
  Serial.print("IP Address: ");
  Serial.println(ip);

  // print the received signal strength:
  long rssi = WiFi.RSSI();
  Serial.print("signal strength (RSSI):");
  Serial.print(rssi);
  Serial.println(" dBm");
  // print where to go in a browser:
  Serial.print("To see this page in action, open a browser to http://");
  Serial.println(ip);
}

1. シリアルモニタにWebサーバ(Arduino)のIPアドレスが示されるので，それをメモする．以下の例では"192.168.11.6"です．
2. スマホでWebブラウザを立ち上げる．
3. ブラウザのURLに上記IPアドレスを入れる．
4. 以下のような画面で，LEDを点灯/消灯させる．


:::warning
注目するのはArduino UNO R4 Wi-Fiのボードに内蔵のLEDです．
:::

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# LEDマトリクスの制御とWi-Fi通信を組み合わせれば，スマホの操作でロゴを流す/止めるが出来るはず．