Serial Port (Communication port) not working. Please Help

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using System.IO;
5. using System.IO.Ports;
6. using UnityEngine.UI;
7.  
8. public class ComPortScript : MonoBehaviour {
9.  
10.     public string COMNAME;
11.     private SerialPort sp = new SerialPort();
12.  
13.  
14.     // Use this for initialization
15.     void Start () {
16.         sp.PortName = COMNAME;
17.         sp.BaudRate = 9600;
18.         sp.Parity = Parity.None;
19.         sp.DataBits = 8;
20.         sp.StopBits = StopBits.One;
21.         sp.ReadTimeout = 50;
22.         sp.Open();
23.         sp.DiscardInBuffer();
24.         //sp.DiscardOutBuffer();
25.     }
26.  
27.     private void OnDisable()
28.     {
29.         sp.Close();
30.         Debug.Log("port is closing");
31.     }
32.     void findComPorts()
33.     {
34.         List<string> ports = new List<string>() { SerialPort.GetPortNames() + "" };
35.         Debug.Log(ports + "this is ports");
36.     }
37.     // Update is called once per frame
38.     void Update () {
39.  
40.         List<byte[]> DataList = new List<byte[]>();
41.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2A, 0x20, 0x03, 0x0C });
42.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2A, 0x21, 0x03, 0x0D });
43.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2A, 0x22, 0x03, 0x0E });
44.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2A, 0x23, 0x03, 0x0F });
45.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2A, 0x24, 0x03, 0x08 });
46.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2A, 0x25, 0x03, 0x09 });
47.         //B
48.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2B, 0x20, 0x03, 0x0D });
49.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2B, 0x21, 0x03, 0x0C });
50.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2B, 0x22, 0x03, 0x0F });
51.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2B, 0x23, 0x03, 0x0E });
52.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2B, 0x24, 0x03, 0x09 });
53.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2B, 0x25, 0x03, 0x08 });
54.         //C
55.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2C, 0x20, 0x03, 0x0A });
56.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2C, 0x21, 0x03, 0x0B });
57.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2C, 0x22, 0x03, 0x08 });
58.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2C, 0x23, 0x03, 0x09 });
59.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2C, 0x24, 0x03, 0x0E });
60.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2C, 0x25, 0x03, 0x0F });
61.         //D
62.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2D, 0x20, 0x03, 0x0B });
63.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2D, 0x21, 0x03, 0x0A });
64.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2D, 0x22, 0x03, 0x09 });
65.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2D, 0x23, 0x03, 0x08 });
66.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2D, 0x24, 0x03, 0x0F });
67.         DataList.Add(new byte[] { 0x02, 0x20, 0x27, 0x2D, 0x25, 0x03, 0x0E });
68.  
69.         if (sp.IsOpen)
70.         {
71.             if (Input.GetKey(KeyCode.A))
72.             {
73.                 sp.DiscardInBuffer();
74.                 sp.DiscardOutBuffer();
75.                 Debug.Log("its open");
76.                 sp.Write(new byte[] { 0x02, 0x20, 0x27, 0x2B, 0x20, 0x03, 0x0D } + "");
77.                 sp.WriteLine("02 20 27 2A 20 03 0C");
78.                 sp.WriteLine(DataList[1] + "");
79.                 sp.WriteLine(new byte[] { 0x02, 0x20, 0x27, 0x2B, 0x20, 0x03, 0x0D } + "");
80.  
81.              
82.                 sp.DiscardOutBuffer();
83.             }
84.         }
85.     }
86.  
87.  
88. }
89.  

Help me please, i could not get the serial port to work, it is connected to a vending machine that supposed to dispense item after i press a certain key on the keyboard. Any way to fix this?

 

The first step I would try is to connect this to another pc running hyperterminal and see what is being sent.

 

Actually i just found out how to fix it, instead of those sp.writes i did. It should be "sp.write(datalist, 0, datalist.length)" i hope i can help someone that is trying to work with this. Previously i was only sending a short part of the datalist as i did not clarify the length of lines being send through the communication port or serial port.