Merge pull request #464 from twa127/master

[hackapet/Adafruit_Blinka.git] / src / busio.py

diff --git a/src/busio.py b/src/busio.py
index 9003bab9f257add8fef9108b88e449aebe1a398a..b02311e29705ae018a3ff7fcb56bdb64b13d7e60 100755 (executable)
--- a/src/busio.py
+++ b/src/busio.py
@@ -7,51 +7,112 @@ See `CircuitPython:busio` in CircuitPython for more details.
 * Author(s): cefn
 """
 
 * Author(s): cefn
 """
 

+try:
+    import threading
+except ImportError:
+    threading = None
+
+import adafruit_platformdetect.constants.boards as ap_board
+import adafruit_platformdetect.constants.chips as ap_chip

 from adafruit_blinka import Enum, Lockable, agnostic
 from adafruit_blinka.agnostic import board_id, detector
 from adafruit_blinka import Enum, Lockable, agnostic
 from adafruit_blinka.agnostic import board_id, detector

-import adafruit_platformdetect.board as ap_board
+
+# pylint: disable=import-outside-toplevel,too-many-branches,too-many-statements
+# pylint: disable=too-many-arguments,too-many-function-args,consider-using-with
+

 
 class I2C(Lockable):
 
 class I2C(Lockable):

-    def __init__(self, scl, sda, frequency=400000):
+    """
+    Busio I2C Class for CircuitPython Compatibility. Used
+    for both MicroPython and Linux.
+    """
+
+    def __init__(self, scl, sda, frequency=100000):

         self.init(scl, sda, frequency)
 
     def init(self, scl, sda, frequency):
         self.init(scl, sda, frequency)
 
     def init(self, scl, sda, frequency):

+        """Initialization"""

         self.deinit()
         if detector.board.ftdi_ft232h:
         self.deinit()
         if detector.board.ftdi_ft232h:

-            from adafruit_blinka.microcontroller.ft232h.i2c import I2C
-            self._i2c = I2C()
+            from adafruit_blinka.microcontroller.ft232h.i2c import I2C as _I2C
+
+            self._i2c = _I2C(frequency=frequency)
+            return
+        if detector.board.binho_nova:
+            from adafruit_blinka.microcontroller.nova.i2c import I2C as _I2C
+
+            self._i2c = _I2C(frequency=frequency)
+            return
+        if detector.board.microchip_mcp2221:
+            from adafruit_blinka.microcontroller.mcp2221.i2c import I2C as _I2C
+
+            self._i2c = _I2C(frequency=frequency)
+            return
+        if detector.board.greatfet_one:
+            from adafruit_blinka.microcontroller.nxp_lpc4330.i2c import I2C as _I2C
+
+            self._i2c = _I2C(frequency=frequency)
+            return
+        if detector.board.pico_u2if:
+            from adafruit_blinka.microcontroller.pico_u2if.i2c import I2C as _I2C
+
+            self._i2c = _I2C(scl, sda, frequency=frequency)
+            return
+        if detector.chip.id == ap_chip.RP2040:
+            from adafruit_blinka.microcontroller.rp2040.i2c import I2C as _I2C
+
+            self._i2c = _I2C(scl, sda, frequency=frequency)

             return
             return

-        elif detector.board.any_embedded_linux:
+        if detector.board.any_embedded_linux:

             from adafruit_blinka.microcontroller.generic_linux.i2c import I2C as _I2C
         else:
             from adafruit_blinka.microcontroller.generic_linux.i2c import I2C as _I2C
         else:

-            from machine import I2C as _I2C
+            from adafruit_blinka.microcontroller.generic_micropython.i2c import (
+                I2C as _I2C,
+            )

         from microcontroller.pin import i2cPorts
         from microcontroller.pin import i2cPorts

+

         for portId, portScl, portSda in i2cPorts:
         for portId, portScl, portSda in i2cPorts:

-            if scl == portScl and sda == portSda:
-                self._i2c = _I2C(portId, mode=_I2C.MASTER, baudrate=frequency)
-                break
+            try:
+                # pylint: disable=unexpected-keyword-arg
+                if scl == portScl and sda == portSda:
+                    self._i2c = _I2C(portId, mode=_I2C.MASTER, baudrate=frequency)
+                    break
+                # pylint: enable=unexpected-keyword-arg
+            except RuntimeError:
+                pass

         else:
         else:

-            raise NotImplementedError(
-                "No Hardware I2C on (scl,sda)={}\nValid UART ports: {}".format((scl, sda), i2cPorts)
+            raise ValueError(
+                "No Hardware I2C on (scl,sda)={}\nValid I2C ports: {}".format(
+                    (scl, sda), i2cPorts
+                )

             )
             )

+        if threading is not None:
+            self._lock = threading.RLock()

 
     def deinit(self):
 
     def deinit(self):

+        """Deinitialization"""

         try:
             del self._i2c
         except AttributeError:
             pass
 
     def __enter__(self):
         try:
             del self._i2c
         except AttributeError:
             pass
 
     def __enter__(self):

+        if threading is not None:
+            self._lock.acquire()

         return self
 
     def __exit__(self, exc_type, exc_value, traceback):
         return self
 
     def __exit__(self, exc_type, exc_value, traceback):

+        if threading is not None:
+            self._lock.release()

         self.deinit()
 
     def scan(self):
         self.deinit()
 
     def scan(self):

+        """Scan for attached devices"""

         return self._i2c.scan()
 
     def readfrom_into(self, address, buffer, *, start=0, end=None):
         return self._i2c.scan()
 
     def readfrom_into(self, address, buffer, *, start=0, end=None):

-        if start is not 0 or end is not None:
+        """Read from a device at specified address into a buffer"""
+        if start != 0 or end is not None:

             if end is None:
                 end = len(buffer)
             buffer = memoryview(buffer)[start:end]
             if end is None:
                 end = len(buffer)
             buffer = memoryview(buffer)[start:end]


@@ -59,86 +120,178 @@ class I2C(Lockable):
         return self._i2c.readfrom_into(address, buffer, stop=stop)
 
     def writeto(self, address, buffer, *, start=0, end=None, stop=True):
         return self._i2c.readfrom_into(address, buffer, stop=stop)
 
     def writeto(self, address, buffer, *, start=0, end=None, stop=True):

+        """Write to a device at specified address from a buffer"""

         if isinstance(buffer, str):
             buffer = bytes([ord(x) for x in buffer])
         if isinstance(buffer, str):
             buffer = bytes([ord(x) for x in buffer])

-        if start is not 0 or end is not None:
+        if start != 0 or end is not None:

             if end is None:
                 return self._i2c.writeto(address, memoryview(buffer)[start:], stop=stop)
             if end is None:
                 return self._i2c.writeto(address, memoryview(buffer)[start:], stop=stop)

-            else:
-                return self._i2c.writeto(address, memoryview(buffer)[start:end], stop=stop)
+            return self._i2c.writeto(address, memoryview(buffer)[start:end], stop=stop)

         return self._i2c.writeto(address, buffer, stop=stop)
 
         return self._i2c.writeto(address, buffer, stop=stop)
 

-    def writeto_then_readfrom(self, address, buffer_out, buffer_in, *, out_start=0, out_end=None, in_start=0, in_end=None, stop=False):
-        return self._i2c.writeto_then_readfrom(address, buffer_out, buffer_in,
-                                               out_start=out_start, out_end=out_end,
-                                               in_start=in_start, in_end=in_end, stop=stop)
+    def writeto_then_readfrom(
+        self,
+        address,
+        buffer_out,
+        buffer_in,
+        *,
+        out_start=0,
+        out_end=None,
+        in_start=0,
+        in_end=None,
+        stop=False
+    ):
+        """ "Write to a device at specified address from a buffer then read
+        from a device at specified address into a buffer
+        """
+        return self._i2c.writeto_then_readfrom(
+            address,
+            buffer_out,
+            buffer_in,
+            out_start=out_start,
+            out_end=out_end,
+            in_start=in_start,
+            in_end=in_end,
+            stop=stop,
+        )
+

 
 class SPI(Lockable):
 
 class SPI(Lockable):

+    """
+    Busio SPI Class for CircuitPython Compatibility. Used
+    for both MicroPython and Linux.
+    """
+

     def __init__(self, clock, MOSI=None, MISO=None):
         self.deinit()
         if detector.board.ftdi_ft232h:
             from adafruit_blinka.microcontroller.ft232h.spi import SPI as _SPI
             from adafruit_blinka.microcontroller.ft232h.pin import SCK, MOSI, MISO
     def __init__(self, clock, MOSI=None, MISO=None):
         self.deinit()
         if detector.board.ftdi_ft232h:
             from adafruit_blinka.microcontroller.ft232h.spi import SPI as _SPI
             from adafruit_blinka.microcontroller.ft232h.pin import SCK, MOSI, MISO

+
+            self._spi = _SPI()
+            self._pins = (SCK, MOSI, MISO)
+            return
+        if detector.board.binho_nova:
+            from adafruit_blinka.microcontroller.nova.spi import SPI as _SPI
+            from adafruit_blinka.microcontroller.nova.pin import SCK, MOSI, MISO
+
+            self._spi = _SPI(clock)
+            self._pins = (SCK, MOSI, MISO)
+            return
+        if detector.board.greatfet_one:
+            from adafruit_blinka.microcontroller.nxp_lpc4330.spi import SPI as _SPI
+            from adafruit_blinka.microcontroller.nxp_lpc4330.pin import SCK, MOSI, MISO
+

             self._spi = _SPI()
             self._pins = (SCK, MOSI, MISO)
             return
             self._spi = _SPI()
             self._pins = (SCK, MOSI, MISO)
             return

-        elif detector.board.any_embedded_linux:
+        if detector.board.pico_u2if:
+            from adafruit_blinka.microcontroller.pico_u2if.spi import SPI as _SPI
+
+            self._spi = _SPI(clock)  # this is really all that's needed
+            self._pins = (clock, clock, clock)  # will determine MOSI/MISO from clock
+            return
+        if detector.chip.id == ap_chip.RP2040:
+            from adafruit_blinka.microcontroller.rp2040.spi import SPI as _SPI
+
+            self._spi = _SPI(clock, MOSI, MISO)  # Pins configured on instantiation
+            self._pins = (clock, clock, clock)  # These don't matter, they're discarded
+            return
+        if detector.board.any_embedded_linux:

             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         else:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         else:

-            from machine import SPI as _SPI
+            from adafruit_blinka.microcontroller.generic_micropython.spi import (
+                SPI as _SPI,
+            )

         from microcontroller.pin import spiPorts
         from microcontroller.pin import spiPorts

+

         for portId, portSck, portMosi, portMiso in spiPorts:
         for portId, portSck, portMosi, portMiso in spiPorts:

-            if ((clock == portSck) and                   # Clock is required!
-                (MOSI == portMosi or MOSI == None) and   # But can do with just output
-                (MISO == portMiso or MISO == None)):      # Or just input
+            if (
+                (clock == portSck)
+                and MOSI in (portMosi, None)  # Clock is required!
+                and MISO in (portMiso, None)  # But can do with just output
+            ):  # Or just input

                 self._spi = _SPI(portId)
                 self._pins = (portSck, portMosi, portMiso)
                 break
         else:
                 self._spi = _SPI(portId)
                 self._pins = (portSck, portMosi, portMiso)
                 break
         else:

-            raise NotImplementedError(
-                "No Hardware SPI on (SCLK, MOSI, MISO)={}\nValid SPI ports:{}".
-                format((clock, MOSI, MISO), spiPorts))
+            raise ValueError(
+                "No Hardware SPI on (SCLK, MOSI, MISO)={}\nValid SPI ports:{}".format(
+                    (clock, MOSI, MISO), spiPorts
+                )
+            )

 
     def configure(self, baudrate=100000, polarity=0, phase=0, bits=8):
 
     def configure(self, baudrate=100000, polarity=0, phase=0, bits=8):

+        """Update the configuration"""

         if detector.board.any_raspberry_pi or detector.board.any_raspberry_pi_40_pin:
         if detector.board.any_raspberry_pi or detector.board.any_raspberry_pi_40_pin:

-            from adafruit_blinka.microcontroller.bcm283x.pin import Pin
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif detector.board.BEAGLEBONE_AI:

             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif detector.board.any_beaglebone:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif detector.board.any_beaglebone:

-            from adafruit_blinka.microcontroller.am335x.pin import Pin

             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI

-        elif board_id == ap_board.ORANGE_PI_PC or board_id == ap_board.ORANGE_PI_R1 or board_id == ap_board.ORANGE_PI_ZERO:
-            from adafruit_blinka.microcontroller.allwinner_h3.pin import Pin
+        elif detector.board.any_orange_pi:
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif detector.board.any_nanopi and detector.chip.id == ap_chip.SUN8I:

             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.GIANT_BOARD:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.GIANT_BOARD:

-            from adafruit_blinka.microcontroller.sama5.pin import Pin

             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.CORAL_EDGE_TPU_DEV:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.CORAL_EDGE_TPU_DEV:

-            from adafruit_blinka.microcontroller.nxp_imx8m.pin import Pin
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif board_id == ap_board.CORAL_EDGE_TPU_DEV_MINI:

             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.ODROID_C2:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.ODROID_C2:

-            from adafruit_blinka.microcontroller.amlogic.s905.pin import Pin
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif board_id == ap_board.ODROID_C4:
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif board_id == ap_board.ODROID_XU4:

             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.DRAGONBOARD_410C:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.DRAGONBOARD_410C:

-            from adafruit_blinka.microcontroller.snapdragon.apq8016.pin import Pin

             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.JETSON_NANO:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.JETSON_NANO:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI

-            from adafruit_blinka.microcontroller.tegra.t210.pin import Pin

         elif board_id == ap_board.JETSON_TX1:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.JETSON_TX1:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI

-            from adafruit_blinka.microcontroller.tegra.t210.pin import Pin

         elif board_id == ap_board.JETSON_TX2:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.JETSON_TX2:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI

-            from adafruit_blinka.microcontroller.tegra.t186.pin import Pin

         elif board_id == ap_board.JETSON_XAVIER:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
         elif board_id == ap_board.JETSON_XAVIER:
             from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI

-            from adafruit_blinka.microcontroller.tegra.t194.pin import Pin
+        elif board_id == ap_board.JETSON_NX:
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif detector.board.ROCK_PI_S:
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif detector.board.ROCK_PI_4:
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif detector.board.SIFIVE_UNLEASHED:
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI

         elif detector.board.ftdi_ft232h:
             from adafruit_blinka.microcontroller.ft232h.spi import SPI as _SPI
         elif detector.board.ftdi_ft232h:
             from adafruit_blinka.microcontroller.ft232h.spi import SPI as _SPI

-            from adafruit_blinka.microcontroller.ft232h.pin import Pin
+        elif detector.board.binho_nova:
+            from adafruit_blinka.microcontroller.nova.spi import SPI as _SPI
+        elif detector.board.greatfet_one:
+            from adafruit_blinka.microcontroller.nxp_lpc4330.spi import SPI as _SPI
+        elif board_id in (
+            ap_board.PINE64,
+            ap_board.PINEBOOK,
+            ap_board.PINEPHONE,
+            ap_board.SOPINE,
+        ):
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif board_id == ap_board.PINEH64:
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif board_id == ap_board.CLOCKWORK_CPI3:
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif board_id == ap_board.ONION_OMEGA2:
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif detector.board.any_lubancat and detector.chip.id == ap_chip.IMX6ULL:
+            from adafruit_blinka.microcontroller.generic_linux.spi import SPI as _SPI
+        elif detector.board.pico_u2if:
+            from adafruit_blinka.microcontroller.pico_u2if.spi import SPI as _SPI
+        elif detector.chip.id == ap_chip.RP2040:
+            from adafruit_blinka.microcontroller.rp2040.spi import SPI as _SPI

         else:
         else:

-            from machine import SPI as _SPI
-            from machine import Pin
+            from adafruit_blinka.microcontroller.generic_micropython.spi import (
+                SPI as _SPI,
+            )

 
         if self._locked:
             # TODO check if #init ignores MOSI=None rather than unsetting, to save _pinIds attribute
 
         if self._locked:
             # TODO check if #init ignores MOSI=None rather than unsetting, to save _pinIds attribute


@@ -148,56 +301,89 @@ class SPI(Lockable):
                 phase=phase,
                 bits=bits,
                 firstbit=_SPI.MSB,
                 phase=phase,
                 bits=bits,
                 firstbit=_SPI.MSB,

-                sck=Pin(self._pins[0].id),
-                mosi=Pin(self._pins[1].id),
-                miso=Pin(self._pins[2].id)

             )
         else:
             raise RuntimeError("First call try_lock()")
 
     def deinit(self):
             )
         else:
             raise RuntimeError("First call try_lock()")
 
     def deinit(self):

+        """Deinitialization"""

         self._spi = None
         self._pinIds = None
 
         self._spi = None
         self._pinIds = None
 

+    @property
+    def frequency(self):
+        """Return the baud rate if implemented"""
+        try:
+            return self._spi.frequency
+        except AttributeError:
+            raise NotImplementedError(
+                "Frequency attribute not implemented for this platform"
+            ) from AttributeError
+

     def write(self, buf, start=0, end=None):
     def write(self, buf, start=0, end=None):

+        """Write to the SPI device"""

         return self._spi.write(buf, start, end)
 
     def readinto(self, buf, start=0, end=None, write_value=0):
         return self._spi.write(buf, start, end)
 
     def readinto(self, buf, start=0, end=None, write_value=0):

+        """Read from the SPI device into a buffer"""

         return self._spi.readinto(buf, start, end, write_value=write_value)
 
         return self._spi.readinto(buf, start, end, write_value=write_value)
 

-    def write_readinto(self, buffer_out, buffer_in,  out_start=0, out_end=None, in_start=0, in_end=None):
-        return self._spi.write_readinto(buffer_out, buffer_in, out_start, out_end, in_start, in_end)
+    def write_readinto(
+        self, buffer_out, buffer_in, out_start=0, out_end=None, in_start=0, in_end=None
+    ):
+        """Write to the SPI device and read from the SPI device into a buffer"""
+        return self._spi.write_readinto(
+            buffer_out, buffer_in, out_start, out_end, in_start, in_end
+        )

 
 
 class UART(Lockable):
 
 
 class UART(Lockable):

+    """
+    Busio UART Class for CircuitPython Compatibility. Used
+    for MicroPython and a few other non-Linux boards.
+    """
+

     class Parity(Enum):
     class Parity(Enum):

-        pass
+        """Parity Enumeration"""
+
+        pass  # pylint: disable=unnecessary-pass

 
     Parity.ODD = Parity()
     Parity.EVEN = Parity()
 
 
     Parity.ODD = Parity()
     Parity.EVEN = Parity()
 

-    def __init__(self,
-                 tx,
-                 rx,
-                 baudrate=9600,
-                 bits=8,
-                 parity=None,
-                 stop=1,
-                 timeout=1000,
-                 receiver_buffer_size=64,
-                 flow=None):
+    def __init__(
+        self,
+        tx,
+        rx,
+        baudrate=9600,
+        bits=8,
+        parity=None,
+        stop=1,
+        timeout=1000,
+        receiver_buffer_size=64,
+        flow=None,
+    ):

         if detector.board.any_embedded_linux:
         if detector.board.any_embedded_linux:

-            raise RuntimeError('busio.UART not supported on this platform. Please use pyserial instead.')
+            raise RuntimeError(
+                "busio.UART not supported on this platform. Please use pyserial instead."
+            )
+        if detector.board.binho_nova:
+            from adafruit_blinka.microcontroller.nova.uart import UART as _UART
+        elif detector.board.greatfet_one:
+            from adafruit_blinka.microcontroller.nxp_lpc4330.uart import UART as _UART
+        elif detector.chip.id == ap_chip.RP2040:
+            from adafruit_blinka.microcontroller.rp2040.uart import UART as _UART

         else:
             from machine import UART as _UART
         else:
             from machine import UART as _UART

+

         from microcontroller.pin import uartPorts
 
         self.baudrate = baudrate
 
         if flow is not None:  # default 0
             raise NotImplementedError(
         from microcontroller.pin import uartPorts
 
         self.baudrate = baudrate
 
         if flow is not None:  # default 0
             raise NotImplementedError(

-                "Parameter '{}' unsupported on {}".format(
-                    "flow", agnostic.board_id))
+                "Parameter '{}' unsupported on {}".format("flow", agnostic.board_id)
+            )

 
         # translate parity flag for Micropython
         if parity is UART.Parity.ODD:
 
         # translate parity flag for Micropython
         if parity is UART.Parity.ODD:


@@ -209,35 +395,87 @@ class UART(Lockable):
         else:
             raise ValueError("Invalid parity")
 
         else:
             raise ValueError("Invalid parity")
 

-        # check tx and rx have hardware support
-        for portId, portTx, portRx in uartPorts:  #
-            if portTx == tx and portRx == rx:
-                self._uart = _UART(
-                    portId,
-                    baudrate,
-                    bits=bits,
-                    parity=parity,
-                    stop=stop,
-                    timeout=timeout,
-                    read_buf_len=receiver_buffer_size
-                )
-                break
-        else:
-            raise NotImplementedError(
-                "No Hardware UART on (tx,rx)={}\nValid UART ports: {}".format((tx, rx), uartPorts)
+        if detector.chip.id == ap_chip.RP2040:
+            self._uart = _UART(
+                tx,
+                rx,
+                baudrate=baudrate,
+                bits=bits,
+                parity=parity,
+                stop=stop,

             )
             )

+        else:
+            # check tx and rx have hardware support
+            for portId, portTx, portRx in uartPorts:  #
+                if portTx == tx and portRx == rx:
+                    self._uart = _UART(
+                        portId,
+                        baudrate,
+                        bits=bits,
+                        parity=parity,
+                        stop=stop,
+                        timeout=timeout,
+                        read_buf_len=receiver_buffer_size,
+                    )
+                    break
+            else:
+                raise ValueError(
+                    "No Hardware UART on (tx,rx)={}\nValid UART ports: {}".format(
+                        (tx, rx), uartPorts
+                    )
+                )

 
     def deinit(self):
 
     def deinit(self):

+        """Deinitialization"""
+        if detector.board.binho_nova:
+            self._uart.deinit()

         self._uart = None
 
     def read(self, nbytes=None):
         self._uart = None
 
     def read(self, nbytes=None):

+        """Read from the UART"""

         return self._uart.read(nbytes)
 
     def readinto(self, buf, nbytes=None):
         return self._uart.read(nbytes)
 
     def readinto(self, buf, nbytes=None):

+        """Read from the UART into a buffer"""

         return self._uart.readinto(buf, nbytes)
 
     def readline(self):
         return self._uart.readinto(buf, nbytes)
 
     def readline(self):

+        """Read a line of characters up to a newline charater from the UART"""

         return self._uart.readline()
 
     def write(self, buf):
         return self._uart.readline()
 
     def write(self, buf):

+        """Write to the UART from a buffer"""

         return self._uart.write(buf)
         return self._uart.write(buf)

+
+
+class OneWire:
+    """
+    Stub class for OneWire, which is currently not implemented
+    """
+
+    def __init__(self, pin):
+        raise NotImplementedError("OneWire has not been implemented")
+
+    def deinit(self):
+        """
+        Deinitialize the OneWire bus and release any hardware resources for reuse.
+        """
+        raise NotImplementedError("OneWire has not been implemented")
+
+    def reset(self):
+        """
+        Reset the OneWire bus and read presence
+        """
+        raise NotImplementedError("OneWire has not been implemented")
+
+    def read_bit(self):
+        """
+        Read in a bit
+        """
+        raise NotImplementedError("OneWire has not been implemented")
+
+    def write_bit(self, value):
+        """
+        Write out a bit based on value.
+        """
+        raise NotImplementedError("OneWire has not been implemented")