M5StackCore2TFMiniSSample.Program.cs

using nanoFramework.M5Stack;
using System;
using System.IO.Ports;
using System.Threading;
using Console = nanoFramework.M5Stack.Console;

namespace M5StackCore2TFMiniSSample
{
    public class Program
    {
        const int TFMINI_FRAME_SIZE = 9;

        private static SerialPort TFMiniS;
        public static void Main()
        {
            try
            {
                Setup();
                Loop();
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Could not find a TFMini-S sensor, check wiring! {ex.Message}");
            }
        }

        private static void Setup()
        {
            M5Core2.InitializeScreen();
            Console.Clear();
            Console.ForegroundColor = System.Drawing.Color.White;
            Console.WriteLine("Starting..");

            // UART2(G13:RXD2,G14:TXD2)設定
            TFMiniS = new SerialPort("COM2", 115200, Parity.None, 8, StopBits.One);
            TFMiniS.Open();

            //
            Console.WriteLine("Open Serial Port..");
        }

        private static void Loop()
        {
            while (true)
            {
                try
                {
                    var distance = GetValue();

                    if (distance>=0)
                    {
                        Console.CursorTop = 2;
                        Console.WriteLine($"{distance} cm");
                        System.Diagnostics.Debug.WriteLine($"{distance} cm");
                    }

                    // インターバル
                    Thread.Sleep(500);
                }
                catch (Exception ex)
                {
                    Console.WriteLine($"{ex.Message}");
                }
            }
        }

        private static long GetValue()
        {
            byte[] buffers = new byte[TFMINI_FRAME_SIZE];
            byte data = 0x00;
            uint lastByte = 0x00;
            long distance = 0;

            if (TFMiniS.IsOpen)
            {
                while (true)
                {
                    data = (byte)TFMiniS.ReadByte();
                    buffers[0] = data;
                    if (data == 0x59 && lastByte == 0x59)
                    {
                        uint checksum = 0x59 + 0x59;
                        buffers[1] = data;
                        for (int index = 2; index < TFMINI_FRAME_SIZE; index++)
                        {
                            data = (byte)TFMiniS.ReadByte();
                            buffers[index] = data;
                            if (index < TFMINI_FRAME_SIZE - 1)
                            {
                                checksum += data;
                            }
                        }
                        //System.Diagnostics.Debug.WriteLine(BitConverter.ToString(buffers));

                        distance = (buffers[3] << 8) + buffers[2];
                        if (checksum % 256 != buffers[TFMINI_FRAME_SIZE - 1])
                        {
                            distance = -1;
                        }
                        lastByte = 0x00;
                        break;
                    }
                    else
                    {
                        lastByte = data;
                    }
                }
            }

            return distance;
        }
    }
}