To choose step or number of reading

Question

This is the code I have so i did what is I have to select either step or number of readings.So error i get at number of readings saying input string not in a correct format i have commented the line and other one is I need five readings which then will be taken as average. I just want a correction in my code so requesting to please assist me in this.

 

private void CalibrateVoltage_Click(object sender, EventArgs e)

{

//double[] Reading;

//Reading = new double[5];

double startvalue;

double endvalue;

double step;

double sum = 0;

double noofreading;

string op_csv = "Equipment:Calibrator Burster 4462, " + "ID No:565510164849," + "Temp: ," + "Humidity: ," + DateTime.Now.ToString() + "\n";

op_csv = op_csv + "Parameter:DC VOLT O/P" + "\n";

op_csv = op_csv + "SrNo.,Standard Measured Value,Deviation Observed\n";

double diff;

startvalue = Convert.ToDouble(textBox3.Text);

endvalue = Convert.ToDouble(textBox4.Text);

//step = Convert.ToDouble(textBox5.Text);

noofreading = Convert.ToDouble(textBox6.Text);//input string not in a correct format when this textbox is disabled

if (comboBox8.Text == "NumberofReadings")

{

step = (endvalue - startvalue) / noofreading;

}

else

{

step = Convert.ToDouble(textBox5.Text);//gives error

}

Burster_init(serialPort1);

agi_init();

for (double i = startvalue; i <= endvalue; i = i + step)

{

for (double a = 0; a <= 5; a++)

{

if (com_type == 0)

{

burster_send_signal(serialPort1, BursterConstant.burs_Volt, "V", Convert.ToString(i));

}

else

{

burster_send_signal(null, BursterConstant.burs_Volt, "V", Convert.ToString(i));

}

Byte[] burread;

Thread.Sleep(3000);

//burread = Burster_receive_signal(serialPort1);

if (com_type == 0)

{

burread = Burster_receive_signal(serialPort1);

}

else

{

burread = Burster_receive_signal(null);

}

if (burread[0] != 0x06)

{

MessageBox.Show("Burster Error");

return;

}

sum = 0;

agi_send_signal(BursterConstant.burs_Volt);

Byte[] readagilent;

//Thread.Sleep(1000)

Thread.Sleep(3000);

readagilent = Agilent_receive_signal();

double agilent_read_val = agilent_read_value(readagilent);

//double agilent_read_val = agilent_read_value(readagilent);

//agi_send_signal(serialPort2, BursterConstant.burs_Volt);

//Thread.Sleep(1000);

//readagilent = Agilent_receive_signal(serialPort2);

//double agilent_read_val2 = agilent_read_value(readagilent);

sum += agilent_read_val;

sum /= 5;

diff = i - sum;

op_csv = op_csv + "," + i.ToString() + "," + sum.ToString() + "\n";

op_to_csv(op_csv);

}

}

}