#include <M5Core2.h>

#define I2C_DEV_ADDR	    0x16

#define NOWTEMP_REG_ADDR		0x01	// 0x01 - 0x04
#define AVETEMP_REG_ADDR		0x05	// 0x05 - 0x08
#define MAXTEMP_REG_ADDR		0x09	// 0x09 - 0x0C
#define MINTEMP_REG_ADDR		0x0D	// 0x0D - 0x10
#define STAT_REG_ADDR			0x11
#define VRST_REG_ADDR			0x12
#define AVRST_REG_ADDR			0x13
#define SCONF_REG_ADDR			0x14
#define CCONF_REG_ADDR			0x15
#define MODADDR_REG_ADDR		0x16
#define OFFSET_REG_ADDR			0x17	// 0x17 - 0x18
#define VMAJOR_REG_ADDR			0xFA
#define VMINOR_REG_ADDR			0xFB
#define VPATCH_REG_ADDR			0xFC
#define SYSRBT_REG_ADDR			0xFD
#define I2CADDR_REG_ADDR		0xFE
#define INIT_REG_ADDR			0xFF

void setup() {
  M5.begin(true, true, true, true);
  M5.Lcd.setTextSize(3);

  byte error;
  // Set sensing config
  // SCONF: Unit=Celsius
  uint8_t sconf = 0x00;
  Wire.beginTransmission(I2C_DEV_ADDR);
  Wire.write(SCONF_REG_ADDR);
  Wire.write(sconf);
  error = Wire.endTransmission();
  if (error){
    Serial.print("error=");Serial.println(error);
  }
  delay(2000);  // Wait until the config is written and the device reboots

  // Set Communication config
  // CCONF: RS485 baudrate=9600, RS485=Modbus, USB Auto Tx=10sec, USB Auto Tx=Disable
  uint8_t cconf = 0x02;
  Wire.beginTransmission(I2C_DEV_ADDR);
  Wire.write(CCONF_REG_ADDR);
  Wire.write(cconf);
  error = Wire.endTransmission();
  if (error){
    Serial.print("error=");Serial.println(error);
  }
  delay(2000);
}

void loop() {
  union _32bit_u
  {
    uint8_t uint8_data[4];
    int32_t int32_data;
  } temp_values[4];
  float temperatures[4];
  const char *str_prefix[4] = {"Now: ", "Ave: ", "Max: ", "Min: "};

  M5.Lcd.setCursor(0, 0);

  Wire.beginTransmission(I2C_DEV_ADDR);
  Wire.write(NOWTEMP_REG_ADDR);
  Wire.endTransmission(false);
  Wire.requestFrom(I2C_DEV_ADDR, 4 * 4);
  for(int i = 0; i < 4; i++) {
    for(int j = 0; j < 4; j++) {
      temp_values[i].uint8_data[j] = Wire.read();
    }
    temperatures[i] = (float)(temp_values[i].int32_data) * 0.01f;

    char strBuf[12];
    sprintf(strBuf, "%s%6.2f", str_prefix[i], temperatures[i]);
    M5.Lcd.println(strBuf);
  }
  delay(2000);
}

using System;
using System.IO.Ports;  // https://www.nuget.org/packages/System.IO.Ports

public class k_thermocouple_usb_logger
{
    static SerialPort? _serialPort;
    static bool _continue;
    static string _portName = "";

    public static int Main(string[] args)
    {
        StringComparer stringComparer = StringComparer.OrdinalIgnoreCase;
        Console.WriteLine("Obtain temperatures from Type-K Thermocouple Thermometer via USB and save them to CSV.\n(The USB auto tx mode must be enabled.)\n");
        Console.WriteLine("Available ports:");
        foreach (string s in SerialPort.GetPortNames())
            Console.WriteLine("\t{0}", s);
        _portName = InputPortName();
        _serialPort = new SerialPort(_portName, 921600, Parity.None, 8, StopBits.One);
        if(_serialPort.IsOpen) {
            Console.WriteLine("Error: {0} is already open.", _portName);
            return 1;
        }
        _serialPort.ReadTimeout = _serialPort.WriteTimeout = 300;
        _serialPort.Open();

        Thread loggingThread = new Thread(LoggingThread);
        _continue = true;
        loggingThread.Start();
        Console.WriteLine("\nStart logging. Type QUIT to exit.");
        while (_continue)
        {
            string message = Console.ReadLine()!;
            if (stringComparer.Equals("quit", message)) {
                _continue = false;
            }
        }
        loggingThread.Join();
        _serialPort.Close();
        return 0;
    }

    public static void LoggingThread()
    {
        while (_continue)
        {
            try
            {
                string message = _serialPort!.ReadLine();
                string text = DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss") + "," + message;
                Console.WriteLine(text);
                File.AppendAllText("./temperature_log_" + _portName + ".csv", text + '\n');
            }
            catch (TimeoutException) { }
        }
    }

    public static string InputPortName()
    {
        string portName;
        string[] ports = SerialPort.GetPortNames();
        string defaultPortName = ports.Length >= 1 ? ports[0] : "COM1";
        Console.Write("Enter COM port value (Default: {0}): ", defaultPortName);
        portName = Console.ReadLine()!;
        if (portName == "" || !(portName.ToLower()).StartsWith("com")) {
            portName = defaultPortName;
        }
        return portName;
    }
}