ESP32 Async web server / websocket weather station.

bmx280 connected to pins 21 and 22
sd card reader/writer on pins 5,18,19,and 23

• Sends weather data to a mysql database every minute.

• updates the clients every 30 seconds.

• reads the sensors every 30 seconds.

• connects to wifi

• retrieves time from ntp servers

• if index.htm is not present on the SD card, it loads a default webpage to the card.

• provides real time bi-directional communication between the clients and the ESP-32

• a new index.htm can be uploaded from the client interface, and once uploaded, all the clients will refresh to the new page.

• programming can be updated using the arduino OTA interface.

• it will maintain state between reboots.

  Database Table idweather = <{idweather: }>, date = <{date: }>, temp = <{temp: }>, press = <{press: }>, p64 = <{p64: }>, humid = <{humid: }>

Files

• weatherotawebsocketserver03182021.ino
• WiFiCred.h
• bcbaws.h
• bcbsdcard.h
• bcbbmx.h

weatherotawebsocketserver03182021.ino

internal rtc variables

const char *ntpServer = "pool.ntp.org";

const long gmtOffset_sec = -18000;

const int daylightOffset_sec = 3600;

define functions

void TaskRelay(void *pvParameters); // maintains the websocket display

void initWiFi(); initializes wifi

void initTime(); initializes the real-time clock.

String printLocalHour(); retrieves the time

String printLocalTime(); retrieves the date and time

void updateDB(); send data to the mysql database

WiFiCred.h

put your wifi credentials here

//wifi connection credentials

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

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

bcbaws.h

variables

//set initial state

struct State {   
  float humidity;
  float pressure;
  double pressure64;
  float temp;	  String filename;
  bool reload;
  String json;
  bool ota;
  float dew () {
    return  temp - ((100 - humidity) / 5.);
  }

};

State state = {0.00, 0.00, 0.00, 0.00,false,"",false};


// web server variables

AsyncWebServer server(80);

AsyncWebSocket ws("/ws");

bool wifiavail = false;

define functions

String getJson(bool b); creates the json object for sending to the client

void notifyClients(); sends data to clients

void notifyInitialClients; sends data to clients with a flag

void handleWebSocketMessage(void *arg, uint8_t *data, size_t len); handles websocket messages

void onEvent(AsyncWebSocket *server, AsyncWebSocketClient *client,
	     AwsEventType type, void *arg, uint8_t *data, size_t len);
	     
void initWebSocket(); initializes websockets

void initWebServer(); initializes webserver

void parseCommand(String command); parses commands from the clients

bcbsdcard.h

variables

const char htmlCode[]PROGMEM default webpage

xSemaphoreHandle semFile = xSemaphoreCreateMutex(); // file 
operation lock

functions

void initSDCard();

void appendFile(fs::FS &fs, const char * path, const char * message);

void renameFile(fs::FS &fs, const char * path1, const char * path2);

void deleteFile(fs::FS &fs, const char * path);

// write the default index.htm to SPIFFS 

//  check if index exists and only update if it doesn't

void checkForIndex();

bcbbmx.h

variables

#define BMX_ADDRESS 0x76

//create a BMx280I2C object using the I2C interface with I2C Address 0x76

BMx280I2C bmx280(BMX_ADDRESS);

functions

void initBmx280()

void doSensorMeasurement()

index.htm

variables

var gateway = `ws://${window.location.hostname}/ws`;

var websocket;

var state = {};

var json = {};

functions

function initWebSocket() opens a connection to the server

function onOpen(event) connection opened

function onClose(event) connection closed

function onMessage(event) message handler

function onLoad(event) page is loaded

function processFile(e) read a text file, break it into 512k chunks and send it to the server

function sendMessage(data, index) send a message to the server.