private void buttonCalibrate_Click(object sender, EventArgs e)
{
float Vdd = 0, Vpp = 0;
float measuredVdd = 0;
bool calSucceed = true;
try
{
measuredVdd = float.Parse(textBoxVDD.Text);
}
catch
{
MessageBox.Show("Invalid 'volts measured' value.");
return;
}
// Cal the ADC results
Pk2.ReadPICkitVoltages(ref Vdd, ref Vpp);
measuredVdd /= Vdd; //ratio
if (measuredVdd > 1.25F)
{
measuredVdd = 1.25F;
calSucceed = false;
}
if (measuredVdd < 0.75F)
{
measuredVdd = 0.75F;
calSucceed = false;
}
float calFactor = 256F * measuredVdd; // 512 is 1:1 calibration factor
Pk2.SetVoltageCals((ushort)calFactor, 0x00, 0x80); // leave Vdd cals unchanged for now.
// Now that we have an accurate ADC reading, we can self-cal the VDD setpoints.
// Vdd Offset = (3 - (4*V3)/V4)*CCP4
// Vdd CalFactor = 1/(V4 - V3) * 128.
// where V3 = actual voltage at SetVDDVoltage(3.0)
// V4 = actual voltage at SetVDDVoltage(4.0)
// CCP4 = CalculateVddCPP(4.0F) >> 6
float offset = 0;
float calCCP = 0;
float Vdd3v = 0;
Pk2.SetVDDVoltage(3.0F, 2.00F);
Thread.Sleep(150);
Pk2.ReadPICkitVoltages(ref Vdd, ref Vpp);
Vdd3v = Vdd;
Pk2.SetVDDVoltage(4.0F, 2.70F);
Thread.Sleep(150);
Pk2.ReadPICkitVoltages(ref Vdd, ref Vpp);
offset = (3 - (4 * Vdd3v) / Vdd) * (Pk2.CalculateVddCPP(4.0F) >> 6);
if (offset > 127F)
{
offset = 127F;
calSucceed = false;
}
if (offset < -128F)
{
offset = -128F;
calSucceed = false;
}
calCCP = (1 / (Vdd - Vdd3v)) * 128;
if (calCCP > 173) // 135%
{
calCCP = 173;
calSucceed = false;
}
if (calCCP < 83) // 65%
{
calCCP = 83;
calSucceed = false;
}
if (calSucceed)
{
labelGoodCal.Visible = true;
labelBadCal.Visible = false;
Pk2.SetVoltageCals((ushort)calFactor, (byte)offset, (byte)(calCCP + 0.5));
}
else
{
labelGoodCal.Visible = false;
labelBadCal.Visible = true;
Pk2.SetVoltageCals(0x0100, 0x00, 0x80); // leave uncal'd
}
buttonCalibrate.Enabled = false;
Pk2.VddOff();
}