M5Stack MQTT Client demo

M5Stack_MQTT_Client.ino

#include <M5Stack.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>

#include "time.h"
#define JST     3600*9

#include <Arduino.h>
#include <vector>
#include <M5GFX.h>
M5GFX display;

#define LINE_COUNT 4

std::vector<int> points[LINE_COUNT];
int colors[] = { TFT_RED, TFT_GREEN, TFT_BLUE, TFT_CYAN, TFT_MAGENTA, TFT_YELLOW };
int xoffset, yoffset, point_count;
int virtual_width;
int virtual_height;
int zoom = 1;


WiFiClient wifiClient;
PubSubClient client(wifiClient);

const char* ssid = "<wifi ssid>";
const char* wifi_password = "<wifi passwoord>";
const char* mqttServer = "<mqtt server>";
const char* mqttClientID = "M5Core";
const char* mqttUsername = "<mqtt username>";
const char* mqttPassword = "<mqtt password>";
const char* mqttTopicName = "homeassistant/sensor/m5atom";
const int mqttPort = 1883;



void wifi_connect(void) {
  Serial.print("WiFi Connenting");
  //M5.Lcd.print("WiFi Connenting");
  WiFi.begin(ssid, wifi_password);
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    //M5.Lcd.print(".");
    delay(1000);
  }
  Serial.println("");
//  M5.Lcd.println("");
  Serial.print("Connected : ");
  //M5.Lcd.print("Connected : ");
  Serial.println(WiFi.localIP());
//  M5.Lcd.println(WiFi.localIP());
  long rssi = WiFi.RSSI();
  Serial.print("RSSI:");
  //M5.Lcd.print("RSSI : ");
  Serial.println(rssi);
//  M5.Lcd.println(rssi);
}

void printLocalTime() {
  struct tm timeinfo;
  if (!getLocalTime(&timeinfo)) {
    M5.Lcd.println("Failed to obtain time");
    return;
  }
  
  Serial.print(&timeinfo, "%A, %B %d %Y %H:%M:%S");
  
  M5.Lcd.setTextColor(WHITE, BLACK);
  M5.Lcd.println(&timeinfo, "%A, %B %d %Y %H:%M");
}


int getBaseColor(int x, int y) {
  return ((x ^ y) & 3 || ((x - xoffset) & 31 && y & 31) ? TFT_BLACK : ((!y || x == xoffset) ? TFT_WHITE : TFT_DARKGREEN));
}


void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  //  M5.Lcd.print("Message arrived [");
  Serial.print(topic);
  //  M5.Lcd.print(topic);
  Serial.print("] ");
  //  M5.Lcd.print("] ");

  //Transform subject (topic) and value (payload) to String
  payload[length] = '\0';
  String strTopic = String(topic);
  String strPayload = String((char*)payload);


  //  for (int i = 0; i < length; i++) {
  ////    Serial.print((char)payload[i]);
  //    //      M5.Lcd.print((char)payload[i]);
  //  }


  Serial.println(strPayload);
  //  M5.Lcd.println(strPayload);

  StaticJsonDocument<200> doc;
  DeserializationError error = deserializeJson(doc, strPayload);
  if (error) {
    Serial.print(F("deserializeJson() failed: "));
    M5.Lcd.print(F("deserializeJson() failed: "));
    Serial.println(error.f_str());
    M5.Lcd.println(error.f_str());
    return;
  }
  double temp = doc["Temperature"];
  double humi = doc["Humidity"];
  int co2 = doc["CO2"];
  int rssi_dev = doc["RSSI"];

  static int count;
  points[0][count % point_count] = temp * -1;     //RED
  points[1][count % point_count] = humi * -1;     //GREEN
  points[2][count % point_count] = (co2 / 50) * -1;     //BLUE
  points[3][count % point_count] = rssi_dev * -1;    //CYAN

  ++count;
  display.waitDisplay();
  display.startWrite();
  int index1 = count % point_count;
  for (int x = 0; x < point_count - 1; x++) {
    int index0 = index1;
    index1 = (index0 + 1) % point_count;
    for (int i = 0; i < LINE_COUNT; i++) {
      int y = points[i][index0];
      if (y != points[i][index1]) {
        display.fillRect(x * zoom, (y + yoffset) * zoom, zoom, zoom, getBaseColor(x, y));
      }
    }

    for (int i = 0; i < LINE_COUNT; i++) {
      int y = points[i][index1];
      display.fillRect(x * zoom, (y + yoffset) * zoom, zoom, zoom, colors[i]);
    }
  }
  display.endWrite();

  M5.Lcd.setCursor(1, 1);
  printLocalTime();

  M5.Lcd.setCursor(1, M5.Lcd.height() - 8);
  M5.Lcd.setTextColor(RED, BLACK);
  M5.Lcd.print("T:");
  M5.Lcd.print(temp);
  M5.Lcd.print("*C");
  M5.Lcd.print(", ");
  M5.Lcd.setTextColor(GREEN, BLACK);
  M5.Lcd.print("H:");
  M5.Lcd.print(humi);
  M5.Lcd.print("%RH");
  M5.Lcd.print(", ");
  M5.Lcd.setTextColor(BLUE, BLACK);
  M5.Lcd.print("CO2:");
  M5.Lcd.print(co2);
  M5.Lcd.print("ppm");
  M5.Lcd.print(", ");
  M5.Lcd.setTextColor(M5.Lcd.color565(0, 255, 255), BLACK);
  M5.Lcd.print("RSSI:");
  M5.Lcd.print(rssi_dev);
  M5.Lcd.print("dBm");
}


void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    //M5.Lcd.print("Attempting MQTT connection...");
    if ( client.connect(mqttClientID, mqttUsername, mqttPassword)) {
      Serial.println("connected");
      //M5.Lcd.println("connected");
      client.subscribe(mqttTopicName);
      //break;
    } else {
      Serial.print("failed, rc=");
      M5.Lcd.print("failed, rc=");
      Serial.print(client.state());
      M5.Lcd.print(client.state());
      Serial.println(" try again in 5 seconds");
      M5.Lcd.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}


void drawBG() {
  display.begin();

  if (display.isEPD())  {
    display.setEpdMode(epd_mode_t::epd_fastest);
    display.invertDisplay(true);
    display.clear(TFT_BLACK);
  }
  if (display.width() < display.height())  {
    display.setRotation(display.getRotation() ^ 1);
  }
  zoom = (display.width() / 480) + 1;

  virtual_width  = display.width() / zoom;
  virtual_height = display.height() / zoom;

  xoffset = virtual_width  >> 1;
  yoffset = virtual_height >> 1;
  point_count = virtual_width + 1;

  for (int i = 0; i < LINE_COUNT; i++)  {
    points[i].resize(point_count);
  }

  display.startWrite();
  for (int y = 0; y < virtual_height; y++)  {
    for (int x = 0; x < virtual_width; x++) {
      auto color = getBaseColor(x, y - yoffset);
      if (color) {
        display.fillRect(x * zoom, y * zoom, zoom, zoom, color);
      }
    }
  }
  display.endWrite();
}

void setup() {
  M5.begin();
  delay(50);
  Serial.begin(115200);

  wifi_connect();

  client.setBufferSize(512);
  client.setServer(mqttServer, mqttPort);
  client.setCallback(callback);

  configTime( JST, 0, "ntp.nict.jp", "ntp.jst.mfeed.ad.jp");

  drawBG();
}



void loop() {
  if (!client.connected()) {
    reconnect();
  }
  client.loop();
}