Add Missing Type Annotations

adafruit_pn532/uart.py

@@ -17,6 +17,12 @@ using UART.
 __version__ = "0.0.0+auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_PN532.git"
 
+try:
+    from typing import Optional
+    from digitalio import DigitalInOut
+    from busio import UART
+except ImportError:
+    pass
 
 import time
 from adafruit_pn532.adafruit_pn532 import PN532, BusyError
@@ -25,7 +31,9 @@ from adafruit_pn532.adafruit_pn532 import PN532, BusyError
 class PN532_UART(PN532):
     """Driver for the PN532 connected over Serial UART"""
 
-    def __init__(self, uart, *, reset=None, debug=False):
+    def __init__(
+        self, uart: UART, *, reset: Optional[DigitalInOut] = None, debug: bool = False
+    ) -> None:
         """Create an instance of the PN532 class using Serial connection.
         Optional reset pin and debugging output.
         """
@@ -33,7 +41,7 @@ class PN532_UART(PN532):
         self._uart = uart
         super().__init__(debug=debug, reset=reset)
 
-    def _wakeup(self):
+    def _wakeup(self) -> None:
         """Send any special commands/data to wake up PN532"""
         if self._reset_pin:
             self._reset_pin.value = True
@@ -44,7 +52,7 @@ class PN532_UART(PN532):
         )  # wake up!
         self.SAM_configuration()
 
-    def _wait_ready(self, timeout=1):
+    def _wait_ready(self, timeout: float = 1) -> bool:
         """Wait `timeout` seconds"""
         timestamp = time.monotonic()
         while (time.monotonic() - timestamp) < timeout:
@@ -54,7 +62,7 @@ class PN532_UART(PN532):
         # Timed out!
         return False
 
-    def _read_data(self, count):
+    def _read_data(self, count: int) -> bytearray:
         """Read a specified count of bytes from the PN532."""
         frame = self._uart.read(count)
         if not frame:
@@ -63,7 +71,7 @@ class PN532_UART(PN532):
             print("Reading: ", [hex(i) for i in frame])
         return frame
 
-    def _write_data(self, framebytes):
+    def _write_data(self, framebytes: bytearray) -> None:
         """Write a specified count of bytes to the PN532"""
         self._uart.reset_input_buffer()
         self._uart.write(framebytes)