中国の Espressif Systems 社が作成したマイクロコントローラで、次の特徴を持つ。
比較項目 | ESP32 | ESP8266 |
対応する無線通信 | Wifi, Bluetooth | Wifi |
CPU | 32bit, dualcore, 240MHz | 32bit, singlecore, 80MHz |
Espressif 製のモジュール名 | ESP-WROOM-32 | ESP-WROOM-2 |
単体の価格(秋月電子) | 550円 | 400円 |
ESP32用の開発ボードはいくつかある。今回は、Switchscience の ESPr Developer 32 を使用する。
https://dl.espressif.com/dl/package_esp32_index.jsonを書き込み OK をクリックする。
接続できたと思ったら、次のプログラム(Arduino ではスケッチと呼ぶ)を試してみる。
void setup() { Serial.begin(115200); } void loop() { Serial.println("Hello World."); delay(1000); }うまくいけば、1秒(1000ミリ秒)に1回、"Hello World." と表示される。
#include "WiFi.h" void setup() { Serial.begin(115200); // Set WiFi to station mode and disconnect from an AP if it was previously connected WiFi.mode(WIFI_STA); WiFi.disconnect(); delay(100); Serial.println("Setup done"); } void loop() { Serial.println("scan start"); // WiFi.scanNetworks will return the number of networks found int n = WiFi.scanNetworks(); Serial.println("scan done"); if (n == 0) { Serial.println("no networks found"); } else { Serial.print(n); Serial.println(" networks found"); for (int i = 0; i < n; ++i) { // Print SSID and RSSI for each network found Serial.print(i + 1); Serial.print(": "); Serial.print(WiFi.SSID(i)); Serial.print(" ("); Serial.print(WiFi.RSSI(i)); Serial.print(")"); Serial.println((WiFi.encryptionType(i) == WIFI_AUTH_OPEN)?" ":"*"); delay(10); } } Serial.println(""); // Wait a bit before scanning again delay(5000); }うまくいけば、無線LANの情報が表示されるはずである。
本学の学内無線LAN は "Captive Portal" と呼ばれる仕組みを使っている。
ESP32 をこれに対応させることができれば、利用範囲は広まる。
-----BEGIN CERTIFICATE----- MIIDxTCCAq2gAwIBAgIBADANBgkqhkiG9w0BAQsFADCBgzELMAkGA1UEBhMCVVMx EDAOBgNVBAgTB0FyaXpvbmExEzARBgNVBAcTClNjb3R0c2RhbGUxGjAYBgNVBAoT EUdvRGFkZHkuY29tLCBJbmMuMTEwLwYDVQQDEyhHbyBEYWRkeSBSb290IENlcnRp ZmljYXRlIEF1dGhvcml0eSAtIEcyMB4XDTA5MDkwMTAwMDAwMFoXDTM3MTIzMTIz NTk1OVowgYMxCzAJBgNVBAYTAlVTMRAwDgYDVQQIEwdBcml6b25hMRMwEQYDVQQH EwpTY290dHNkYWxlMRowGAYDVQQKExFHb0RhZGR5LmNvbSwgSW5jLjExMC8GA1UE AxMoR28gRGFkZHkgUm9vdCBDZXJ0aWZpY2F0ZSBBdXRob3JpdHkgLSBHMjCCASIw DQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAL9xYgjx+lk09xvJGKP3gElY6SKD E6bFIEMBO4Tx5oVJnyfq9oQbTqC023CYxzIBsQU+B07u9PpPL1kwIuerGVZr4oAH /PMWdYA5UXvl+TW2dE6pjYIT5LY/qQOD+qK+ihVqf94Lw7YZFAXK6sOoBJQ7Rnwy DfMAZiLIjWltNowRGLfTshxgtDj6AozO091GB94KPutdfMh8+7ArU6SSYmlRJQVh GkSBjCypQ5Yj36w6gZoOKcUcqeldHraenjAKOc7xiID7S13MMuyFYkMlNAJWJwGR tDtwKj9useiciAF9n9T521NtYJ2/LOdYq7hfRvzOxBsDPAnrSTFcaUaz4EcCAwEA AaNCMEAwDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMCAQYwHQYDVR0OBBYE FDqahQcQZyi27/a9BUFuIMGU2g/eMA0GCSqGSIb3DQEBCwUAA4IBAQCZ21151fmX WWcDYfF+OwYxdS2hII5PZYe096acvNjpL9DbWu7PdIxztDhC2gV7+AJ1uP2lsdeu 9tfeE8tTEH6KRtGX+rcuKxGrkLAngPnon1rpN5+r5N9ss4UXnT3ZJE95kTXWXwTr gIOrmgIttRD02JDHBHNA7XIloKmf7J6raBKZV8aPEjoJpL1E/QYVN8Gb5DKj7Tjo 2GTzLH4U/ALqn83/B2gX2yKQOC16jdFU8WnjXzPKej17CuPKf1855eJ1usV2GDPO LPAvTK33sefOT6jEm0pUBsV/fdUID+Ic/n4XuKxe9tQWskMJDE32p2u0mYRlynqI 4uJEvlz36hz1 -----END CERTIFICATE-----
const char* ssid = "XXXXXXXXXXXXX"; // your network SSID (name of wifi network) const char* password = "XXXXXXXXXXXXX"; // your network password const char* IFTTTkey = "XXXXXXXXXXXXXXXXXXXXXX"; // IFTTT webhook key for me const char* server = "maker.ifttt.com"; // Server URL const char* EventName = "XXXXXXXXXX"; // IFTTT Event Name const char* ifttt_root_ca= \ "-----BEGIN CERTIFICATE-----\n" \ "MIIDxTCCAq2gAwIBAgIBADANBgkqhkiG9w0BAQsFADCBgzELMAkGA1UEBhMCVVMx\n" \ "EDAOBgNVBAgTB0FyaXpvbmExEzARBgNVBAcTClNjb3R0c2RhbGUxGjAYBgNVBAoT\n" \ "EUdvRGFkZHkuY29tLCBJbmMuMTEwLwYDVQQDEyhHbyBEYWRkeSBSb290IENlcnRp\n" \ "ZmljYXRlIEF1dGhvcml0eSAtIEcyMB4XDTA5MDkwMTAwMDAwMFoXDTM3MTIzMTIz\n" \ "NTk1OVowgYMxCzAJBgNVBAYTAlVTMRAwDgYDVQQIEwdBcml6b25hMRMwEQYDVQQH\n" \ "EwpTY290dHNkYWxlMRowGAYDVQQKExFHb0RhZGR5LmNvbSwgSW5jLjExMC8GA1UE\n" \ "AxMoR28gRGFkZHkgUm9vdCBDZXJ0aWZpY2F0ZSBBdXRob3JpdHkgLSBHMjCCASIw\n" \ "DQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAL9xYgjx+lk09xvJGKP3gElY6SKD\n" \ "E6bFIEMBO4Tx5oVJnyfq9oQbTqC023CYxzIBsQU+B07u9PpPL1kwIuerGVZr4oAH\n" \ "/PMWdYA5UXvl+TW2dE6pjYIT5LY/qQOD+qK+ihVqf94Lw7YZFAXK6sOoBJQ7Rnwy\n" \ "DfMAZiLIjWltNowRGLfTshxgtDj6AozO091GB94KPutdfMh8+7ArU6SSYmlRJQVh\n" \ "GkSBjCypQ5Yj36w6gZoOKcUcqeldHraenjAKOc7xiID7S13MMuyFYkMlNAJWJwGR\n" \ "tDtwKj9useiciAF9n9T521NtYJ2/LOdYq7hfRvzOxBsDPAnrSTFcaUaz4EcCAwEA\n" \ "AaNCMEAwDwYDVR0TAQH/BAUwAwEB/zAOBgNVHQ8BAf8EBAMCAQYwHQYDVR0OBBYE\n" \ "FDqahQcQZyi27/a9BUFuIMGU2g/eMA0GCSqGSIb3DQEBCwUAA4IBAQCZ21151fmX\n" \ "WWcDYfF+OwYxdS2hII5PZYe096acvNjpL9DbWu7PdIxztDhC2gV7+AJ1uP2lsdeu\n" \ "9tfeE8tTEH6KRtGX+rcuKxGrkLAngPnon1rpN5+r5N9ss4UXnT3ZJE95kTXWXwTr\n" \ "gIOrmgIttRD02JDHBHNA7XIloKmf7J6raBKZV8aPEjoJpL1E/QYVN8Gb5DKj7Tjo\n" \ "2GTzLH4U/ALqn83/B2gX2yKQOC16jdFU8WnjXzPKej17CuPKf1855eJ1usV2GDPO\n" \ "LPAvTK33sefOT6jEm0pUBsV/fdUID+Ic/n4XuKxe9tQWskMJDE32p2u0mYRlynqI\n" \ "4uJEvlz36hz1\n" \ "-----END CERTIFICATE-----\n";プログラム本体
/* IFTTT trigger sample */ #include <WiFiClientSecure.h> #include "WiFiIDs.h" WiFiClientSecure client; int val1 = 1000, val2 = 1001, val3 = 1002; // dummy data void setup() { // Serial Monitor Serial.begin(115200); // WiFi WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) { // attempt to connect to Wifi network: Serial.print("."); delay(500); } Serial.println("WiFi Connected"); // CACert client.setCACert(ifttt_root_ca); } void loop() { val3 = val2; val2 = val1; val1 = touchRead(T0); Serial.println(val1); if ( val1 + val2 + val3 < 80 ) { // touched Serial.println("\nStarting connection to server..."); if (!client.connect(server, 443)) { Serial.print ("Connection failed!"); Serial.println(server); return; } String request = "/trigger/"; request += EventName; request += "/with/key/"; request += IFTTTkey; request += "?value1=" + String(val1) + "&value2=" + String(val2) + "&value3=" + String(val3); Serial.println("GET " + request + " HTTP/1.1"); client.println("GET " + request + " HTTP/1.1"); client.print ("Host: "); client.println(server); client.println("Connection: close"); client.println(); while (client.connected()) { String line = client.readStringUntil('\n'); if (line == "\r") { Serial.println("headers received"); break; } } client.stop(); val1 = 1000, val2 = 1001, val3 = 1002; delay(10000); } delay(100); }