M5StickC-RemoE.ino

#include <M5StickC.h>
#include <WiFi.h>
#include <HTTPClient.h>

#define REMO_API_URL "https://api.nature.global/1/appliances"
#define REMO_AUTH "Bearer ***"
#define WIFI_SSID "***"
#define WIFI_PASSWORD "***"

HTTPClient http;

void setup() {    
  M5.begin();
  M5.Axp.ScreenBreath(10);
  M5.Lcd.setRotation(3);
  M5.Lcd.setTextSize(2);
  M5.Lcd.fillScreen(BLACK);

  M5.Lcd.println("start wifi");

  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
  while (WiFi.status() != WL_CONNECTED) {
    M5.Lcd.print(".");
    delay(500);
  }

  M5.Lcd.println("connected!");
  M5.Lcd.println(WiFi.localIP());
  delay(500);
  
}

void loop(){
  if (WiFi.status() != WL_CONNECTED) {
    M5.Lcd.println("Error. \nWiFi not connected");
    return;
  }

  http.begin(REMO_API_URL);
  http.addHeader("Accept", "application/json");
  http.addHeader("Authorization", REMO_AUTH);
  http.GET();
  
  String payload = http.getString();
  http.end();
  
  int p0 = payload.indexOf("epc\":231"); // measured_instantaneous
  int p1 = payload.indexOf("val", p0);
  int p2 = payload.indexOf("updated_at", p1);
  String val = payload.substring(p1 + 6, p2 - 3);

  M5.Lcd.setRotation(0);
  M5.Lcd.setCursor(2, 140);
  M5.Lcd.fillScreen(BLACK);
  M5.Lcd.print(val);
  M5.Lcd.println(" W");

  int intVal = val.toInt();
  int color;
  if (intVal > 3000) {
    color = TFT_RED;
  } else if (intVal > 2000) {
    color = TFT_YELLOW;
  } else if (intVal > 1000) {
    color = TFT_GREEN;
  } else {
    color = TFT_BLUE;
  }

  M5.Lcd.fillCircle(40, 40, 40, color);
  delay(10000);
}