Try setting the
DtrEnable[
^] and
RtsEnable[
^] properties to
true
: it may be that the unit expects hardware handshaking that HyperTerminal is setting high.
But also try adding the data from your device to the string in your DoUpDate method:
private void DoUpDate(object s, EventArgs e)
{
sendRead.Text += port.ReadLine();
}
Serial ports are slow devices - 9600 baud is less that 1000 characters per second - so you will very likely get a separate DataReceived event for each character. If the final one is a space or unprintable, you might not see anything useful in your text box.