ESP32: Laboratorios

ESP32: Laboratórios

A placa Heltec ESP32 LoRa é uma placa de desenvolvimento que integra três formas distintas de comunicação: Wifi, Bluetooth e a rede de comunicação de longo alcance LoRa. Além disto a placa apresenta um display OLED, o que facilita o controle da operação do dispositivo localizado em locais remotos.

Referências sobre o Heltec ESP32

• Heltec ESP32+LoRa Series Quick Start: https://heltec-automation-docs.readthedocs.io/en/latest/esp32/quick_start.html

Instalação da placa do Heltec ESP32 com a IDE do Arduino

1. IDE -> Arquivo -> Preferências
2. URLs Adicionais para Gerenciadores de Placa: https://github.com/Heltec-Aaron-Lee/WiFi_Kit_series/releases/download/0.0.5/package_heltec_esp32_index.json
3. Ferramentas -> Gerenciadores de Placa -> Instalar Heltec ESP32 Series Dev/boards
4. Selecionar placa WiFi LoRa 32

Laboratório 1: Wifi

Exemplo pronto da biblioteca padrão do Arduino: Arquivo -> Exemplos -> Wifi -> SimpleWifiServer:

• Configurar apenas ssid e passwd da rede Wifi;
• Identificar via terminal serial o endereço IP recebido pelo ESP32;
• Será possível controlar led (gpio 5, ou outro) via nagerador Web.

Laboratório 2: Bluetooth

Exemplo pronto da biblioteca padrão do Arduino: Arquivo -> Exemplos -> BluetoothSerial -> SerialToSerialBT:

Exemplo de interação bluetooth entre ESP32 e Android Serial Bluetooth Terminal.

• Carregar código no ESP32;
• Instalar aplicativo Serial Bluetooth Terminal no Android;
• Parear o ESP32 com o Android;
• Trocar mensagens seriais entre o terminal do ESP32 e o aplicativo Serial Bluetooth Terminal

Laboratório 3: Bluetooth Low Energy - BLE

Ver detalhes do BLE: https://randomnerdtutorials.com/esp32-bluetooth-low-energy-ble-arduino-ide/.

Biblioteca: https://github.com/nkolban/ESP32_BLE_Arduino

• Exemplo pronto Arquivo -> Exemplos -> ESP BLE Arduino -> BLEserver;
• Instalar aplicativo BLE Terminal no Android;
• Conectar ao dispositivo.

Laboratório 4: Servidor Web e Display OLED

Exemplo de Web Server construído a partir de dois exemplos prontos

• Wifi: busca de redes e conexão baseadas no exemplo:

Arquivo -> Exemplos -> Heltec ESP Dev-Boards -> Factory_Tests -> WIFI_Kit_32_Factory_Test
* Servidor Web: baseado no exemplo:
Arquivo -> Exemplos -> Wifi -> SimpleWiFiServer

Código

<syntaxhighlight lang="c"> /*

* Web Server
* 
* Wifi: busca de redes e conexão baseadas no exemplo:
* Arquivo -> Exemplos -> Heltec ESP Dev-Boards -> Factory_Tests -> WIFI_Kit_32_Factory_Test
* 
* Servidor Web: baseado no exemplo:
* Arquivo -> Exemplos -> Wifi -> SimpleWiFiServer

• /

1. include "heltec.h"
2. include "WiFi.h"
3. include "images.h"

WiFiServer server(80);

void logo(){ Heltec.display -> clear(); Heltec.display -> drawXbm(0,5,HelTec_LOGO_width,HelTec_LOGO_height,(const unsigned char *)HelTec_LOGO_bits); Heltec.display -> display();

 delay(1000);
 Heltec.display->clear();

}

void wifi_logo(){

 Heltec.display -> clear();
 Heltec.display->drawXbm(34, 19, WiFi_Logo_width, WiFi_Logo_height, WiFi_Logo_bits);
 Heltec.display -> display();
 delay(1000);
 Heltec.display->clear();

}

void WIFISetUp(void) { // Set WiFi to station mode and disconnect from an AP if it was previously connected WiFi.disconnect(true); delay(1000); WiFi.mode(WIFI_STA); WiFi.setAutoConnect(true); WiFi.begin("Zhone_EB1C","aaaaabbbbb"); delay(100);

byte count = 0; while(WiFi.status() != WL_CONNECTED && count < 10) { count ++;

   if (count == 1) Serial.println("Connecting...");

delay(500);

   Heltec.display->clear();

Heltec.display -> drawString(0, 0, "Connecting..."); Heltec.display -> display(); }

Heltec.display -> clear(); if(WiFi.status() == WL_CONNECTED) { Heltec.display -> drawString(0, 0, "Connecting...OK."); Heltec.display -> display(); delay(500);

   Heltec.display -> drawString(0, 10, "IP address: ");
   Heltec.display -> display();
   delay(500);
   Heltec.display -> drawString(0, 20, WiFi.localIP().toString());
   Heltec.display -> display();
   delay(2000);
   Serial.println("WiFi connected");
   Serial.println("IP address: ");
   Serial.println(WiFi.localIP());

} else { Heltec.display -> clear(); Heltec.display -> drawString(0, 0, "Connecting...Failed"); Heltec.display -> display();

   Serial.println("Connecting...Failed");

// while(1); } Heltec.display -> drawString(0, 40, "WIFI Setup done"); Heltec.display -> display();

 Serial.println("WIFI Setup done");

delay(500);

 Heltec.display->clear();

}

void WIFIScan(void) { Heltec.display -> drawString(0, 20, "Scan start..."); Heltec.display -> display();

 Serial.println("Scan start...");

int n = WiFi.scanNetworks(); Heltec.display -> drawString(0, 30, "Scan done"); Heltec.display -> display();

 Serial.println("Scan done");

delay(500); Heltec.display -> clear();

if (n == 0) { Heltec.display -> clear(); Heltec.display -> drawString(0, 0, "no network found"); Heltec.display -> display();

   Serial.println("No network found");

while(1); } else {

   Serial.print(n);

Heltec.display -> drawString(0, 0, (String)n); Heltec.display -> drawString(14, 0, "networks found:"); Heltec.display -> display();

   Serial.print(n);
   Serial.println(" networks found:");

delay(500);

for (int i = 0; i < n; ++i) { // Print SSID and RSSI for each network found Heltec.display -> drawString(0, (i+1)*9,(String)(i + 1)); Heltec.display -> drawString(6, (i+1)*9, ":"); Heltec.display -> drawString(12,(i+1)*9, (String)(WiFi.SSID(i))); Heltec.display -> drawString(90,(i+1)*9, " ("); Heltec.display -> drawString(98,(i+1)*9, (String)(WiFi.RSSI(i))); Heltec.display -> drawString(114,(i+1)*9, ")"); // display.println((WiFi.encryptionType(i) == WIFI_AUTH_OPEN)?" ":"*");

     Serial.print(i+1);
     Serial.print(" : ");
     Serial.print(WiFi.SSID(i));
     Serial.print(" (");
     Serial.print(WiFi.RSSI(i));
     Serial.println(")");

delay(10); } }

Heltec.display -> display(); delay(800); Heltec.display -> clear();

}

void setup() { pinMode(LED,OUTPUT);

Heltec.begin(true /*DisplayEnable Enable*/, false /*LoRa Enable*/, true /*Serial Enable*/);

logo();

 wifi_logo();
 WIFIScan();

WIFISetUp();

 //WiFi.disconnect(true);//重新初始化WIFI
 //delay(1000);
 //WiFi.mode(WIFI_STA);
 //WiFi.setAutoConnect(true);

 server.begin();
 Heltec.display -> drawString(0, 0, "Waiting Web Clients");
 Heltec.display -> display();

}

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
   Heltec.display -> clear();
   Heltec.display -> drawString(0, 0, "New Web Client");
   Heltec.display -> display();
   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 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("Click <a href=\"/H\">here</a> to turn the LED on.
");
           client.print("Click <a href=\"/L\">here</a> to turn the LED off.
");

           // 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, HIGH);               // GET /H turns the LED on
         Heltec.display -> drawString(0, 10, "Turn LED on");
         Heltec.display -> display();
       }
       if (currentLine.endsWith("GET /L")) {
         digitalWrite(LED, LOW);                // GET /L turns the LED off
         Heltec.display -> drawString(0, 10, "Turn LED off");
         Heltec.display -> display();
         
       }
     }
   }
   // close the connection:
   client.stop();
   Serial.println("Client Disconnected.");
 }

}

Referências

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Evandro.cantu (discussão) 15h48min de 8 de fevereiro de 2022 (-03)

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