Allow to set initial RTS and DTR state after connect

serial.go

@@ -78,6 +78,8 @@ type Mode struct {
 	DataBits   int      // Size of the character (must be 5, 6, 7 or 8)
 	Parity     Parity   // Parity (see Parity type for more info)
 	StopBits   StopBits // Stop bits (see StopBits type for more info)
+	InitialRTS bool     // Initial state for RTS
+	InitialDTR bool     // Initial state for DTR
 }
 
 // Parity describes a serial port parity setting

serial_unix.go

@@ -235,6 +235,9 @@ func nativeOpen(portName string, mode *Mode) (*unixPort, error) {
 	// Explicitly disable RTS/CTS flow control
 	setTermSettingsCtsRts(false, settings)
 
+	port.SetDTR(mode.InitialDTR)
+	port.SetRTS(mode.InitialRTS)
+
 	if port.setTermSettings(settings) != nil {
 		port.Close()
 		return nil, &PortError{code: InvalidSerialPort}

serial_windows.go

@@ -451,9 +451,13 @@ func nativeOpen(portName string, mode *Mode) (*windowsPort, error) {
 		return nil, &PortError{code: InvalidSerialPort}
 	}
 	params.Flags &= dcbRTSControlDisbaleMask
+	if mode.InitialRTS {
 		params.Flags |= dcbRTSControlEnable
+	}
 	params.Flags &= dcbDTRControlDisableMask
+	if mode.InitialDTR {
 		params.Flags |= dcbDTRControlEnable
+	}
 	params.Flags &^= dcbOutXCTSFlow
 	params.Flags &^= dcbOutXDSRFlow
 	params.Flags &^= dcbDSRSensitivity