nodemcu-lab-1/src/main.cpp

#include <Arduino.h>
#include <ESP8266WiFi.h>
//#include <WiFiClient.h>
#include <ESP8266WebServer.h>
//#include <ESP8266mDNS.h>
#include <html.h>
#include <Graph.h>
#include <Sensor.h>
#include <WebSocketsServer.h>
#include <ArduinoJson.h>
#include "CpuLoad.h"

const char *ssid = "NodeMCU";

ESP8266WebServer server(80);
Sensor accelerometer = Sensor();
Graph graphAcc = Graph(200, 50);

long int lastDataSend = 0;

WebSocketsServer webSocket = WebSocketsServer(81);

void handleAccelerometer()
{
    int16_t bias = 0;
    const int arr_size = 10000;
    char *html_code = new char[arr_size];
    memset(html_code, '\0', sizeof(char) * arr_size);

    bias += getHtml(HTML_BEGIN, *html_code, arr_size, 0);
    bias += getHtml(STYLE, *html_code, arr_size, bias);
    bias += getHtml(SCRIPT_BEGIN, *html_code, arr_size, bias);
    // for (int i = 0; i != graphAcc.graphSize - 1; i++)
    // {
    //     bias += snprintf((html_code + bias), arr_size - bias, "context.lineTo(%i*2, %i);\n", i, graphAcc.graphArray[i]);
    // }
    bias += getHtml(SCRIPT_END, *html_code, arr_size, bias);
    //bias += snprintf((html_code+bias), arr_size - bias, "<br />Current accelerometer: %i", acc);
    bias += getHtml(HTML_END, *html_code, arr_size, bias);

    server.send(200, "text/html", html_code);

    delete[] html_code;
}

void cookAccelerometer(String &in, int *in_array, int array_size) {
    String *output = &in;
    int *array = in_array;
    DynamicJsonBuffer jsonBuffer;
    JsonObject& root = jsonBuffer.createObject();
    JsonArray& data = root.createNestedArray("data");
    for (int i = 0; i != array_size; i++) {
        data.add(*(array + i));
    }
    root.printTo(*output);
}

int lowFreqFilter(int inputValue, int lastFilteredValue, int alpha) {
    return (lastFilteredValue +  alpha * (inputValue - lastFilteredValue)+100);
}

void updateAccelerometer()
{
    if ((millis() - accelerometer.lastUpdate) > (1000 / graphAcc.graphUpdateRate))
    {   
        int filteredAcc = 0;
        accelerometer.lastValue = map(analogRead(A0), 368, 768, 200, 0);

        if (graphAcc.graphCounter != 0) {
            //filteredAcc = lowFreqFilter(accelerometer.lastValue, graphAcc.graphArray[graphAcc.graphCounter - 1], 0.5);
            filteredAcc = graphAcc.graphArray[graphAcc.graphCounter - 1] + 0.5 * (accelerometer.lastValue - graphAcc.graphArray[graphAcc.graphCounter - 1]);
        }

        if (graphAcc.graphCounter < graphAcc.graphSize - 1)
        {   
            graphAcc.graphArray[graphAcc.graphCounter] = filteredAcc;
            graphAcc.graphCounter++;
        }
        else
        {
            for (int i = 0; i != graphAcc.graphCounter; i++)
            {
                graphAcc.graphArray[i] = graphAcc.graphArray[i + 1];
            }
            graphAcc.graphArray[graphAcc.graphCounter] = filteredAcc;
        }


        accelerometer.lastUpdate = millis();
    }
}


void handleNotFound()
{
    String message = "File Not Found\n\n";
    message += "URI: ";
    message += server.uri();
    message += "\nMethod: ";
    message += (server.method() == HTTP_GET) ? "GET" : "POST";
    message += "\nArguments: ";
    message += server.args();
    message += "\n";
    for (uint8_t i = 0; i < server.args(); i++)
    {
        message += " " + server.argName(i) + ": " + server.arg(i) + "\n";
    }
    server.send(404, "text/plain", message);
}

void sendAccelerometerData() {
    if (millis() - lastDataSend > 50) {
        String word;
        cookAccelerometer(word, graphAcc.graphArray, graphAcc.graphSize);
        webSocket.broadcastTXT(word);
        lastDataSend = millis();
    }
}

//** WEBSOCKET TEST **//
void webSocketEvent(uint8_t num, WStype_t type, uint8_t *payload, size_t length)
{
    switch (type)
    {
    case WStype_DISCONNECTED:
        Serial.printf("[%u] Disconnected!\n", num);
        break;
    case WStype_CONNECTED:
    {
        IPAddress ip = webSocket.remoteIP(num);
        Serial.println("Client connected!");
        Serial.printf("[%u] Connected from %d.%d.%d.%d url: %s\n", num, ip[0], ip[1], ip[2], ip[3], payload);
    }
    break;
    }
}
//** WEBSOCKET TEST END**//

void setup(void)
{
    Serial.begin(115200);
    Serial.setDebugOutput(true);
    Serial.println();

    pinMode(A0, INPUT);
    WiFi.softAP(ssid);

    IPAddress myIP = WiFi.softAPIP();
    Serial.print("AP IP address: ");
    Serial.println(myIP);

    server.on("/accelerometer", handleAccelerometer);
    server.on("/", []() {
        server.send(200, "text/html", "<a href=\"http://192.168.4.1/accelerometer\">Main Page</a>");
    });
    server.onNotFound(handleNotFound);

    server.begin();
    Serial.println("HTTP server started");

    //** WEBSOCKET TEST **//

    webSocket.begin();
    webSocket.onEvent(webSocketEvent);
    //** WEBSOCKET TEST END**//
}

void loop(void)
{   
    updateCpuTime(0);

    server.handleClient();
    webSocket.loop();
    updateAccelerometer();
    sendAccelerometerData();
    
    updateCpuTime(1);
    printCpuLoad();
}