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iotdemo/pyft232.py

@@ -0,0 +1,213 @@
+"""
+Raw level FT232 controll module
+"""
+
+from logging import getLogger
+from queue import Queue
+from threading import Condition, Lock, Thread
+from typing import Callable, Optional
+
+from serial import Serial
+
+__all__ = ('PyFt232', )
+
+
+def _dummy(*_):
+    pass
+
+
+class PyFt232:
+    """
+    Raw level FT232 controll class
+    """
+
+    PKT_START = 0xaa
+    PKT_END = 0xaa
+
+    PKT_CMD_ACK = 0x00
+
+    PKT_CMD_START = 0x01
+    PKT_CMD_START_STOP = 0x00
+    PKT_CMD_START_START = 0x01
+
+    PKT_CMD_LOADING = 0x02
+    PKT_CMD_LOADING_STOP = 0x00
+    PKT_CMD_LOADING_LOAD = 0x01
+
+    PKT_CMD_DETECTION = 0x03
+    PKT_CMD_DETECTION_0 = 0x00
+    PKT_CMD_DETECTION_1 = 0x01
+    PKT_CMD_DETECTION_2 = 0x02
+    PKT_CMD_DETECTION_3 = 0x03
+
+    PKT_CMD_SPEED = 0x04
+    PKT_CMD_SPEED_STOP = 0x00
+    PKT_CMD_SPEED_UP = 0x01
+    PKT_CMD_SPEED_DOWN = 0x02
+
+    #PKT_CMD_AUTO_LOADING = 0x05
+    #PKT_CMD_VERSION = 0x64
+
+    PKT_ID_MAX = 199
+    PKT_ID_ERROR = 0xff
+
+    def __init__(self,
+                 port: str = '/dev/ttyUSB0',
+                 baudrate: int = 19200,
+                 *,
+                 debug: bool = False):
+        self.debug = debug
+        if self.debug:
+            self.logger = getLogger('PYFT232')
+            self.logger.info("serial port %s (%d)", port, baudrate)
+
+        self.__ft232 = None
+        self.__stop_requested = False  # to support graceful exit
+        self.__force_stop = False
+        self.__values = [1] * 14  # Pin status
+        for idx in (0, 1):
+            self.__values[idx] = 0xff  # NC
+
+        # init arduio
+        ft232 = Serial(port=port, baudrate=baudrate, timeout=1)
+        ft232.reset_input_buffer()
+        ft232.reset_output_buffer()
+        self.__ft232 = ft232
+
+        self.__rx = Thread(target=self.__receiver)
+        self.__rx.name = 'Arduino Rx'
+        self.__rx.start()
+
+        self.__init()
+
+        self.__tx_lock = Lock()
+        self.__tx_cv = Condition()
+        self.__tx_queue = Queue()
+        self.__tx = Thread(target=self.__transmitter)
+        self.__tx.name = 'Arduino Tx'
+        self.__tx.start()
+
+    def __del__(self):
+        self.close()
+
+    def __checksum(self, length: int, cmd: int, data: list):
+        return ~((length + cmd + sum(data)) & 0xff) & 0xff
+
+    def __init(self):
+        pass
+
+    # Tx Thread
+    def __transmitter(self):
+        ft232 = self.__ft232
+
+        while True:
+            packet = self.__tx_queue.get()
+            if self.debug:
+                self.logger.info(packet)
+
+            if len(packet) != 2:
+                break
+
+            cmd, data = packet
+            self.__tx_queue.task_done()
+            if cmd is None:
+                break  # End of Tx
+
+            ft232.write(
+                bytes([
+                    PyFt232.PKT_START, 0x05, cmd, data, self.__checksum(0x05, cmd, [data])
+                ]))
+
+    # Rx Thread
+    def __receiver(self):
+        while self.__force_stop is False:
+            packet = self.__receive_packet()
+            if self.debug:
+                self.logger.info(packet)
+            if packet is None:
+                continue
+
+            # TODO : What need to be done?
+            cmd, data = packet
+
+            # run callback
+            with self.__tx_cv:
+                self.__tx_cv.notify()
+
+    def __receive_packet(self):
+        ft232 = self.__ft232
+
+        data = ft232.read()
+        if len(data) == 0 or data[0] != PyFt232.PKT_START:
+            return None
+
+        packet = []
+        while len(packet) != 5:
+            data = ft232.read()
+            if len(data) == 0:
+                return None  # Timeout
+
+            packet.append(data[0])
+
+        length, cmd, data, dataerr, checksum = packet
+        if length != 6:
+            return None
+
+        if cmd != 0x00 or dataerr != 0x00:
+            return None
+
+        if self.__checksum(length, cmd, [data, dataerr]) != checksum:
+            return None
+
+        return (cmd, data)
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.close()
+
+    def close(self) -> None:
+        """
+        Close existing ft232 connection
+        """
+        if self.__ft232 is None:
+            return
+
+        self.__stop_requested = True
+        if self.__force_stop:
+            return
+
+        # post end of tx marker
+        self.__tx_queue.put((None, None, None))
+        self.__tx.join()
+
+        # Stop Rx
+        self.__force_stop = True
+        self.__rx.join()
+
+        # close serial
+        self.__ft232.close()
+
+        if self.debug:
+            self.logger.info("stopped")
+
+    def set(self, cmd: int, value: int) -> bool:
+        """
+        Set ft232 pin with given value
+        """
+        if self.__stop_requested:
+            return False
+
+        with self.__tx_lock:
+            with self.__tx_cv:
+                self.__tx_queue.put((cmd, value))
+                self.__tx_cv.wait()
+
+        return True
+
+    def get(self, pin: int) -> int:
+        """
+        Get current ft232 pin value from proxy
+        """
+        return self.__values[pin]