Version 0.2.0

DTR and RTS control added for CDC ACM driver.

setup.py

@@ -2,7 +2,7 @@ from setuptools import setup
 
 setup(
     name="usbserial4a",
-    version="0.1.10",
+    version="0.2.0",
     description="Python package for Kivy Android USB serial port.",
     long_description="https://github.com/jacklinquan/usbserial4a",
     long_description_content_type="text/markdown",

usbserial4a/__init__.py

@@ -9,4 +9,4 @@ Requires: kivy, pyjnius, pyserial, usb4a
 '''
 
 # Project version
-__version__ = '0.1.10'
+__version__ = '0.2.0'

usbserial4a/cdcacmserial4a.py

@@ -4,6 +4,8 @@ Classes:
 CdcAcmSerial(serial.serialutil.SerialBase)
 '''
 
+from struct import pack, unpack
+import time
 from serial.serialutil import SerialBase, SerialException, to_bytes, \
     portNotOpenError, writeTimeoutError, Timeout
 from usb4a import usb
@@ -15,14 +17,17 @@ class CdcAcmSerial(SerialBase):
     It can be used in a similar way to serial.Serial from pyserial.
     '''
     
-    USB_RECIP_INTERFACE = 0x01
-    USB_RT_ACM = usb.UsbConstants.USB_TYPE_CLASS | USB_RECIP_INTERFACE
+    REQTYPE_HOST2DEVICE = 0x21
+    REQTYPE_DEVICE2HOST = 0xA1
 
-    SET_LINE_CODING = 0x20  # USB CDC 1.1 section 6.2
+    SET_LINE_CODING = 0x20
     GET_LINE_CODING = 0x21
     SET_CONTROL_LINE_STATE = 0x22
     SEND_BREAK = 0x23
     
+    SET_CONTROL_LINE_STATE_DTR = 0x1
+    SET_CONTROL_LINE_STATE_RTS = 0x2
+    
     STOPBIT_MAP = {
         1:0,
         1.5:1,
@@ -87,6 +92,7 @@ class CdcAcmSerial(SerialBase):
             raise SerialException("Could not establish all endpoints!")
         
         self.is_open = True
+        self._set_dtr_rts(self._dtr_state, self._rts_state)
         self._reconfigure_port()
         
     def _open_single_interface(self):
@@ -146,6 +152,19 @@ class CdcAcmSerial(SerialBase):
         self._read_endpoint = self._data_interface.getEndpoint(1)
         self._write_endpoint = self._data_interface.getEndpoint(0)
         
+    def _reconfigure_port(self):
+        '''Reconfigure serial port parameters.'''
+        msg = bytearray([
+            self.baudrate & 0xff,
+            self.baudrate >> 8 & 0xff,
+            self.baudrate >> 16 & 0xff,
+            self.baudrate >> 24 & 0xff,
+            self.STOPBIT_MAP[self.stopbits],
+            self.PARITY_MAP[self.parity],
+            self.bytesize])
+        # Set line coding.
+        self._ctrl_transfer_out(self.SET_LINE_CODING, 0, msg)
+        
     def close(self):
         '''Close the serial port.'''
         if self._connection:
@@ -153,6 +172,8 @@ class CdcAcmSerial(SerialBase):
         self._connection = None
         self.is_open = False
     
+    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -
+    
     @property
     def in_waiting(self):
         '''Return the number of bytes currently in the input buffer.
@@ -164,6 +185,14 @@ class CdcAcmSerial(SerialBase):
         self._read_buffer.extend(self._read())
         return len(self._read_buffer)
     
+    @property
+    def out_waiting(self):
+        '''Return the number of bytes currently in the output buffer.
+        
+        Always return 0.
+        '''
+        return 0
+    
     def read(self, size=1):
         '''Read data from the serial port.
         
@@ -225,6 +254,158 @@ class CdcAcmSerial(SerialBase):
         '''Simply wait some time to allow all data to be written.'''
         pass
     
+    def reset_input_buffer(self):
+        '''Clear input buffer, discarding all that is in the buffer.'''
+        if not self.is_open:
+            raise portNotOpenError
+        self._purgeHwBuffers(True, False)
+
+    def reset_output_buffer(self):
+        '''\
+        Clear output buffer, aborting the current output and discarding all
+        that is in the buffer.
+        '''
+        if not self.is_open:
+            raise portNotOpenError
+        self._purgeHwBuffers(False, True)
+
+    def send_break(self, duration=0.25):
+        '''Send break condition.
+        
+        Parameters:
+            duration (float): break time in seconds.
+        '''
+        if not self.is_open:
+            raise portNotOpenError
+        self._ctrl_transfer_out(
+            self.SEND_BREAK,
+            int(duration * 1000)
+        )
+
+    def _update_break_state(self):
+        '''Send break condition.'''
+        self._set_break(self._break_state)
+        
+    def _update_rts_state(self):
+        '''Set terminal status line: Request To Send.'''
+        self._set_rts(self._rts_state)
+
+    def _update_dtr_state(self):
+        '''Set terminal status line: Data Terminal Ready.'''
+        self._set_dtr(self._dtr_state)
+
+    @property
+    def cts(self):
+        '''Read terminal status line: Clear To Send.'''
+        status = self._poll_modem_status()
+        return bool(status)
+
+    @property
+    def dsr(self):
+        '''Read terminal status line: Data Set Ready.'''
+        status = self._poll_modem_status()
+        return bool(status)
+
+    @property
+    def ri(self):
+        '''Read terminal status line: Ring Indicator.'''
+        status = self._poll_modem_status()
+        return bool(status)
+
+    @property
+    def cd(self):
+        '''Read terminal status line: Carrier Detect.'''
+        status = self._poll_modem_status()
+        return bool(status)
+
+    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -
+    
+    def _ctrl_transfer_out(self, request, value, buf=None):
+        '''USB control transfer out.
+        
+        This function does the USB configuration job.
+        '''
+        result = self._connection.controlTransfer(
+            self.REQTYPE_HOST2DEVICE, 
+            request, 
+            value, 
+            0, 
+            buf, 
+            (0 if buf is None else len(buf)), 
+            self.USB_WRITE_TIMEOUT_MILLIS
+        )
+        
+        return result
+    
+    def _ctrl_transfer_in(self, request, value, buf):
+        '''USB control transfer in.
+        
+        Request for a control message from the device.
+        '''
+        result = self._connection.controlTransfer(
+            self.REQTYPE_DEVICE2HOST,
+            request,
+            value,
+            0,
+            buf,
+            (0 if buf is None else len(buf)),
+            self.USB_READ_TIMEOUT_MILLIS
+        )
+        
+        return result
+
+    def _set_break(self, break_):
+        '''Start or stop a break exception event on the serial line.
+        
+        Parameters:
+            break_ (bool): either start or stop break event.
+        '''
+        pass
+
+    def _set_dtr(self, state):
+        '''Set dtr line.
+        
+        Parameters:
+            state (bool): new DTR logical level.
+        '''
+        self._set_dtr_rts(state, self._rts_state)
+
+    def _set_rts(self, state):
+        '''Set rts line.
+        
+        Parameters:
+            state (bool): new RTS logical level.
+        '''
+        self._set_dtr_rts(self._dtr_state, state)
+
+    def _set_dtr_rts(self, dtr, rts):
+        '''Set dtr and rts lines at once.
+        
+        Parameters:
+            dtr (bool): new DTR logical level.
+            rts (bool): new RTS logical level.
+        '''
+        value = 0
+        if dtr:
+            value |= self.SET_CONTROL_LINE_STATE_DTR
+        if rts:
+            value |= self.SET_CONTROL_LINE_STATE_RTS
+        self._ctrl_transfer_out(
+            self.SET_CONTROL_LINE_STATE,
+            value
+        )
+
+    def _purgeHwBuffers(self, purgeReadBuffers, purgeWriteBuffers):
+        '''Set serial port parameters.
+        
+        Parameters:
+            purgeReadBuffers (bool): need to purge read buffer or not.
+            purgeWriteBuffers (bool): need to purge write buffer or not.
+        Returns:
+            result (bool): successful or not.
+        '''
+        return True
+    
     def _read(self):
         '''Hardware dependent read function.
         
@@ -250,35 +431,15 @@ class CdcAcmSerial(SerialBase):
         read = buf[:totalBytesRead]
         return bytes(read)
     
-    def _send_acm_control_message(self, request, value, buf=None):
-        '''USB control transfer.
+    def _poll_modem_status(self):
+        '''Poll modem status information.
         
-        This function does the USB configuration job.
+        This function allows the retrieve the one status byte of the
+        device, useful in UART mode.
+        
+        Returns:
+            status (int): modem status, as a proprietary bitfield
         '''
-        return self._connection.controlTransfer(
-            self.USB_RT_ACM, 
-            request, 
-            value, 
-            0, 
-            buf,
-            0 if buf is None else len(buf),
-            self.USB_WRITE_TIMEOUT_MILLIS)
-        
-    def _reconfigure_port(self):
-        '''Reconfigure serial port parameters.'''
-        msg = bytearray([
-            self.baudrate & 0xff,
-            self.baudrate >> 8 & 0xff,
-            self.baudrate >> 16 & 0xff,
-            self.baudrate >> 24 & 0xff,
-            self.STOPBIT_MAP[self.stopbits],
-            self.PARITY_MAP[self.parity],
-            self.bytesize])
-        # Set line coding.
-        self._send_acm_control_message(self.SET_LINE_CODING, 0, msg)
-        # Set line state.
-        value = (0x2 if self._rts_state else 0) \
-            or (0x1 if self._dtr_state else 0)
-        self._send_acm_control_message(self.SET_CONTROL_LINE_STATE, value)
+        return 0