---
tags: Arduino
---
# ESP32 NodeMCU-32S Wi-Fi study

不錯的資料:
[ESP32教學](https://www.chosemaker.com/board/esp32/lesson-1/)
[ESP32 Arduino: Soft AP and Station modes](
https://techtutorialsx.com/2021/01/04/esp32-soft-ap-and-station-modes/)
[Create A Web Server w/ ESP32](https://electropeak.com/learn/create-a-web-server-w-esp32/)
[Asynchronous HTTP web server](https://techtutorialsx.com/2017/12/01/esp32-arduino-asynchronous-http-webserver/)
[ESP32 Basic Over The Air (OTA) Programming In Arduino IDE](https://lastminuteengineers.com/esp32-ota-updates-arduino-ide/)
[ESP32 I2C Communication](https://randomnerdtutorials.com/esp32-i2c-communication-arduino-ide/)
[How to use ESP32 Dual Core with Arduino IDE](https://randomnerdtutorials.com/esp32-dual-core-arduino-ide/)

回傳毫秒

 time = millis();

重開機

 ESP.restart();

---

## HW



---
## FW

### R/W flash
有512個位置,每個位置可以放一個byte(0~255)

#include <EEPROMh>

EEPROM.begin(size); //宣告使用EEPROM size個位置

EEPROM.write(add,data);
//全部寫完後:
EEPROM.commit();//一次寫入 or EEPROM.end();

EEPROM.read(add); 

### I2C

#include <Wire.h>

uint8_t slave_address=0x55;
uint8_t buffer[0x40];
uint8_t buffer_count;

void i2c_ram_cmd_send(uint8_t start_address, uint8_t length)
{
  Wire.beginTransmission(slave_address);
  Wire.write(start_address);
  Wire.endTransmission();
  Wire.requestFrom(slave_address, length);
}


void setup() {
  // put your setup code here, to run once:
  Wire.begin();
  Serial.begin(115200);
  while(!Serial);

  pinMode(5,OUTPUT);
}

void wait_data(uint8_t start_pos, uint8_t len)
{
  buffer_count=0;
  while (Wire.available())
  {
    buffer[start_pos+buffer_count] = Wire.read();
    buffer_count = buffer_count + 1;
    if(buffer_count>=len) break;
  }
}


void loop() {
  // put your main code here, to run repeatedly:
  uint8_t cnt;
  uint16_t val;
  while(true)
  {
    if(digitalRead(5))
      digitalWrite(5, LOW);
    else
      digitalWrite(5, HIGH);
      
    delay(1500);
    i2c_ram_cmd_send(0x00,0x20);
    wait_data(0x00,0x20);
    i2c_ram_cmd_send(0x20,0x20);
    wait_data(0x20,0x20);
    delay(500);
    wait_data(0x00, 0x00); //clear dummy 
  
    Serial.println("-");
    for(cnt=0;cnt<0x20;cnt+=2)
    {
      val=buffer[cnt]+buffer[cnt+1]*0x100;
       
      Serial.print(cnt/2);
      Serial.print("==>");
      Serial.println(val);
    }
    Serial.println("**");  
    Serial.println(" ");
  }
}

### Dual core work

TaskHandle_t Task1;
TaskHandle_t Task2;

void Task1code( void * pvParameters ){
  Serial.print("Task1 running on core ");
  Serial.println(xPortGetCoreID());

  for(;;){
    Serial.println(xPortGetCoreID());
    delay(1000);
  } 
}

void Task2code( void * pvParameters ){
  Serial.print("Task2 running on core ");
  Serial.println(xPortGetCoreID());

  for(;;){
    Serial.println(xPortGetCoreID());
    delay(500);
  } 
}
void setup() {
  // put your setup code here, to run once:

  Serial.begin(115200);
  
  xTaskCreatePinnedToCore(
      Task1code,  /* Task Function  */
      "Task1",    /* Name of the task */
      10000,      /* Stack size in words */
      NULL,       /* Task input parameter */
      1,          /* Priority of the task */
      &Task1,     /* Task handle. */
      0);         /* Core where the task should run */          
  
  delay(500);
  
  xTaskCreatePinnedToCore(
    Task2code,   /* Task function. */
    "Task2",     /* name of task. */
    10000,       /* Stack size of task */
    NULL,        /* parameter of the task */
    1,           /* priority of the task */
    &Task2,      /* Task handle */
    1); 
      
}

void loop() {
  // put your main code here, to run repeatedly:
}

### Client 連接
ESP32的預設WIFI模式是STA模式(Client)

#include "WiFi.h"

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

bool check_Wifi_status()
{
  int i=0;
  while(i++<20)
  {
    if(WiFi.status()==WL_CONNECTED) return true;
    delay(1000);
    Serial.print("Wifi status:");
    Serial.println(WiFi.status());
  }
  return false;
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  
  WiFi.begin(ssid,password);
  if(check_Wifi_status())
  {
    Serial.print("WiFi connect OK,local IP:");
    Serial.println(WiFi.localIP()); 
  }
  else
  {
    Serial.println("Wifi NG");
  }
}

void loop() {
  // put your main code here, to run repeatedly:

}

WiFi.status() return:
- WL_CONNECTED: assigned when connected to a WiFi network ==>3
- WL_NO_SHIELD: assigned when no WiFi shield is present ==>255
- WL_IDLE_STATUS: it is a temporary status assigned when WiFi.begin() is called and remains active until the number of attempts expires (resulting in WL_CONNECT_FAILED) or a connection is established (resulting in WL_CONNECTED) ==>0
- WL_NO_SSID_AVAIL: assigned when no SSID are available ==>1
- WL_SCAN_COMPLETED: assigned when the scan networks is completed ==>2
- WL_CONNECT_FAILED: assigned when the connection fails for all the attempts=>4
- WL_CONNECTION_LOST: assigned when the connection is lost =>5
- WL_DISCONNECTED: assigned when disconnected from a network ==>6

### Soft AP

相關函式:

bool softAP(const char* ssid, const char* passphrase = NULL, int channel = 1, int ssid_hidden = 0, int max_connection = 4)

channel:WiFi網絡信道，可選值1~13；
ssid_hidden是否對外隱藏SSID，0-不隱藏，1-隱藏
max_connection最大可接入數，可選值1~4

bool softAPConfig(IPAddress local_ip, IPAddress gateway, IPAddress subnet)

bool softAPdisconnect(bool wifioff = false)

關閉當前AP，若wifioff為true則還將還原網絡設置

### 建立Web Server,讓WiFi連線

#include "WiFi.h"
#include <WebServer.h>

char *ssid="GGG";
char *password="GGGGGG";
int statuscode;
String content;
String room_id="";
char htmlstr[700];

int temp=0;
int volt=0;

//set web server port
WebServer server(80);

void handle_root()
{
  snprintf(htmlstr,700,
  "<!DOCTYPE html>\
<html>\
<head>\
<title> GI GI BO BO！</title>\
<meta http-equiv='Content-Type' content='text/html; charset=utf-8'>\
</head>\
<body>\
<h1>STATUS:</h1>\
<p>Voltage: %d </p>\
<P>Temperature: %d </p>\
</body>\
</html>",temp,volt);
  
  server.send(200,"text/html",htmlstr);
}

void WebcreateServer()
{
      server.on("/", handle_root); 
   
}

bool check_Wifi_status()
{
  int i=0;
  while(i++<20)
  {
    if(WiFi.status()==WL_CONNECTED) return true;
    delay(1000);
    Serial.print("Wifi status:");
    Serial.println(WiFi.status());
  }
  return false;
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  
  WiFi.begin(ssid,password);
  if(check_Wifi_status())
  {
    Serial.print("WiFi connect OK,local IP:");
    Serial.println(WiFi.localIP()); 

    //setup webserver
    WebcreateServer();
    server.begin();
    Serial.println("Server start");
  }
  else
  {
    Serial.println("Wifi NG");
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  server.handleClient();
  temp++;
  volt+=2;
}

不同時間更新網頁,有不同的值

[使用snprintf()函式轉換動態字串、輸出ESP8266溫濕度網頁](https://swf.com.tw/?p=1159)

### Asynchronous HTTP web server 使用
[Installing the Asynchronous Web Server library](https://reacoda.gitbook.io/molemi-iot/introducing-the-nodemcu/display-the-dht11-sensor-reading-on-a-web-server-using-nodemcu./installing-dht-library-on-the-esp8266/installing-the-asynchronous-web-server-library)

//web server

AsyncWebServer server(80);

const char root[] PROGMEM = R"rawliteral(
<!DOCTYPE html>
<html>
<head>
<title> GI GI BO BO！</title>
<meta http-equiv='Content-Type' content='text/html; charset=utf-8'>
</head>
<body>
<h1>STATUS:</h1>
<p>%Voltage% </p>
<P>%Temperature% </p>
</body>
</html>
)rawliteral";

String processor(const String& var)
{
    String a;
    Serial.println(var);
    if(var=="Voltage")
      a="3200";
    else if(var== "Temperature")
      a=3500;
  return(a);  
}

void Task2code( void * pvParameters ){
  
  Serial.print("Task2 running on core ");
  Serial.println(xPortGetCoreID());
  
  server.on("/", HTTP_GET,[](AsyncWebServerRequest *request)
  {
    request->send_P(200, "text/html", root,processor);
  });
  server.begin();
  Serial.println("Server start");
  while(true)
  {
    delay(1);
  } 
}

[ESP32 Arduino Tutorial HTTP server:1. Template processing](https://www.dfrobot.com/blog-1103.html)
[IoT 練習 - ESP Web 介面溫溼度記錄器](https://blog.darkthread.net/blog/temp-humd-esp-web/)

### TCP client 連線

#include "WiFi.h"
#include <WebServer.h>

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

const IPAddress serverIP(192,168,0,5);
uint16_t serverPort=9876;

WiFiClient client;
bool communiction_path;
void setup() {
  // put your setup code here, to run once:
  communiction_path=false;
  Serial.begin(115200);
  Serial.print("connect. ");

  WiFi.begin(ssid,password);

  while(WiFi.status()!=WL_CONNECTED)
  {
    delay(500);
    Serial.print(". ");
  }
  Serial.println(". ");
  Serial.print("IP:");
  Serial.println(WiFi.localIP());

  Serial.print("access to server...");

  if(!client.connect(serverIP,serverPort))
  {
    Serial.println("fail");
  }
  else
  {
    Serial.println("sucess");
    
    client.print("START CONNECT TRANSMIT\r\n");
    delay(10);
    while(client.connected())
    {
      if(client.available())
      {
        String line=client.readStringUntil('\n');
        Serial.println(line);
        if(line=="CONNECT OK")
        {
          Serial.println("communication path ok");
          communiction_path=true;
          break;
        }
      }
    }
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  if(communiction_path)
  {
    while(client.connected())
    {
      if(client.available())
      {
        String line=client.readStringUntil('\n');
        Serial.println(line);
      }
    }   
    Serial.println("discoonct");
    client.stop();
  }
  delay(5000);
}

@@@

**HTML:**

<!DOCTYPE html>        -> 告訴瀏覽器是 HTML5網頁
<html>                 -> 表示html文件
  <head>               -> 標頭(宣告網頁資訊)
    <!-- 網頁的資訊 -->
  </head>
  <body>               -->使用者看的內容
    <!-- 網頁的內容 -->
  </body>
</html>

<head>
  <title>歡迎來到 GI GI BO BO ！</title>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>

看一下:

[Tables Generator 線上製作產生表格 HTML、LaTeX、Markdown 原始碼](https://free.com.tw/tables-generator/)