Problem : Index was outside the bounds of the array.

See more:

C#

Hi guys i try to create Ariplan Attitude . in here i read the serial from gyro but when i wanna read the 4th or 5th element of buffer i cant, i get this error ("Index was outside the bounds of the array in C#")
it seem when i put bytes it cant read 4th and 5th element.
how can i access to this element

the fourth element buffer[4] is read 0 or 1 for positive or negative , the fifth element buffer[5] is show the main number for rotation.

My Question is how can i read the buffer[4] & buffer[5] from serial like this (in Hex): 68 07 00 81 (00) (00) 98 20?

Mycode:

private void serialPort1_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
        {

            // Obtain the number of bytes waiting in the port's buffer
            int bytes = serialPort1.BytesToRead;

            // Create a byte array buffer to hold the incoming data

            byte[] buffer = new byte[bytes];
            

            // Read the data from the port and store it in our buffer
           // if (buffer.Length == 7 )
             serialPort1.Read(buffer, 0, bytes); //bytes
           
             
            

            Log(LogMsgType.Incoming, ByteArrayToHexString(buffer));
           
         //   RxString = port.ReadLine();
         //   ArduinoData = RxString.Split(',', '\n', '\r');
          //  if (ArduinoData.Count() == 7) //ensures we have all data, plus line end ("\n" or "\r")
            if (buffer.Count() == bytes)
            {

                if (buffer[4] == 0) // <--- Problem

                    PitchAngle = Convert.ToDouble(buffer[5]);//<--- Problem
                else
                    PitchAngle = -1.0 * Convert.ToDouble(buffer[5]);//<--- Problem
                // RollAngle = -1.0 * Convert.ToDouble(buffer[5]) * Math.PI / 180;//<--- Problem
                // YawAngle = -1.0 * Convert.ToDouble(ArduinoData[6]) * Math.PI / 180;
                // if (YawAngle < -Math.PI) YawAngle = YawAngle + Math.PI;
                Invalidate();
            }
    
        }