Added support for sending breaks

serial.go

@@ -48,6 +48,9 @@ type Port interface {
 
 	// Close the serial port
 	Close() error
+
+	// Break sends a break for a determined time
+	Break(time.Duration) error
 }
 
 // NoTimeout should be used as a parameter to SetReadTimeout to disable timeout.

serial_darwin.go

@@ -14,6 +14,8 @@ const regexFilter = "^(cu|tty)\\..*"
 const ioctlTcgetattr = unix.TIOCGETA
 const ioctlTcsetattr = unix.TIOCSETA
 const ioctlTcflsh = unix.TIOCFLUSH
+const ioctlTioccbrk = unix.TIOCCBRK
+const ioctlTiocsbrk = unix.TIOCSBRK
 
 func setTermSettingsBaudrate(speed int, settings *unix.Termios) (error, bool) {
 	baudrate, ok := baudrateMap[speed]

serial_freebsd.go

@@ -56,6 +56,8 @@ const tcCRTSCTS uint32 = tcCCTS_OFLOW
 const ioctlTcgetattr = unix.TIOCGETA
 const ioctlTcsetattr = unix.TIOCSETA
 const ioctlTcflsh = unix.TIOCFLUSH
+const ioctlTioccbrk = unix.TIOCCBRK
+const ioctlTiocsbrk = unix.TIOCSBRK
 
 func toTermiosSpeedType(speed uint32) uint32 {
 	return speed

serial_linux.go

@@ -63,6 +63,8 @@ const tcCRTSCTS uint32 = unix.CRTSCTS
 const ioctlTcgetattr = unix.TCGETS
 const ioctlTcsetattr = unix.TCSETS
 const ioctlTcflsh = unix.TCFLSH
+const ioctlTioccbrk = unix.TIOCCBRK
+const ioctlTiocsbrk = unix.TIOCSBRK
 
 func toTermiosSpeedType(speed uint32) uint32 {
 	return speed

serial_openbsd.go

@@ -56,6 +56,8 @@ const tcCRTSCTS uint32 = tcCCTS_OFLOW
 const ioctlTcgetattr = unix.TIOCGETA
 const ioctlTcsetattr = unix.TIOCSETA
 const ioctlTcflsh = unix.TIOCFLUSH
+const ioctlTioccbrk = unix.TIOCCBRK
+const ioctlTiocsbrk = unix.TIOCSBRK
 
 func toTermiosSpeedType(speed uint32) int32 {
 	return int32(speed)

serial_unix.go

@@ -4,6 +4,7 @@
 // license that can be found in the LICENSE file.
 //
 
+//go:build linux || darwin || freebsd || openbsd
 // +build linux darwin freebsd openbsd
 
 package serial
@@ -117,6 +118,20 @@ func (port *unixPort) Write(p []byte) (n int, err error) {
 	return
 }
 
+func (port *unixPort) Break(t time.Duration) error {
+	if err := unix.IoctlSetInt(port.handle, ioctlTiocsbrk, 0); err != nil {
+		return err
+	}
+
+	time.Sleep(t)
+
+	if err := unix.IoctlSetInt(port.handle, ioctlTioccbrk, 0); err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func (port *unixPort) SetMode(mode *Mode) error {
 	settings, err := port.getTermSettings()
 	if err != nil {

serial_windows.go

@@ -381,6 +381,10 @@ func (port *windowsPort) SetReadTimeout(timeout time.Duration) error {
 	return nil
 }
 
+func (port *windowsPort) Break(d time.Duration) error {
+	return &PortError{code: FunctionNotImplemented}
+}
+
 func createOverlappedEvent() (*syscall.Overlapped, error) {
 	h, err := createEvent(nil, true, false, nil)
 	return &syscall.Overlapped{HEvent: h}, err