library and example

README.rst

@@ -93,9 +93,28 @@ Usage Example
 
 .. code-block:: python
 
+    import time
+    import board
     import adafruit_s35710
 
-    print("hello s35710")
+    i2c = board.I2C()
+
+    timer = adafruit_s35710.Adafruit_S35710(i2c)
+
+    timer.alarm = 5
+    print(f"The S-35710 alarm is set for {timer.alarm} seconds")
+
+    countdown = timer.alarm - timer.clock
+
+    while True:
+        print(f"The S-35710 clock is {timer.clock}")
+        countdown = timer.alarm - timer.clock
+        if countdown == 0:
+            timer.alarm = 5
+            print("Alarm reached! Resetting..")
+        else:
+            print(f"The alarm will expire in {countdown} seconds")
+        time.sleep(1)
 
 Documentation
 =============

adafruit_s35710.py

@@ -25,7 +25,75 @@
 * Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
 """
 
-# imports
+import adafruit_bus_device.i2c_device as i2cdevice
+from micropython import const
+
+try:
+    import typing  # pylint: disable=unused-import
+    from busio import I2C
+except ImportError:
+    pass
 
 __version__ = "0.0.0+auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_S35710.git"
+
+
+_DEFAULT_I2C_ADDR = const(0x32)
+
+
+class Adafruit_S35710:
+    """
+    A driver for the S-35710 Low-Power Wake Up Timer
+    """
+
+    def __init__(self, i2c: typing.Type[I2C], address: int = _DEFAULT_I2C_ADDR):
+        """Initialize the S-35710 Wake-Up Timer IC over I2C.
+
+        :param i2c: The I2C bus object.
+        :type i2c: Type[I2C]
+        :param address: The I2C address of the S-35710, defaults to 0x32.
+        :type i2c_address: int
+        """
+        self.i2c_device = i2cdevice.I2CDevice(i2c, address)
+
+    @property
+    def alarm(self):
+        """Wake-up alarm time register value."""
+        try:
+            buffer = bytearray(3)
+            with self.i2c_device as device:
+                device.write_then_readinto(bytearray([0x01]), buffer)
+            value = (buffer[0] << 16) | (buffer[1] << 8) | buffer[2]
+            return value
+        except Exception as error:
+            raise ValueError("Failed to read wake-up time register: ", error) from error
+
+    @alarm.setter
+    def alarm(self, value: int):
+        """Wake-up alarm time register value.
+
+        :param value: the alarm time in seconds
+        :type value: int
+        """
+        try:
+            buffer = bytearray(
+                [0x81, (value >> 16) & 0xFF, (value >> 8) & 0xFF, value & 0xFF]
+            )
+            with self.i2c_device as device:
+                device.write(buffer)
+        except Exception as error:
+            raise ValueError(
+                "Failed to write wake-up time register: ", error
+            ) from error
+
+    @property
+    def clock(self):
+        """Current time register value."""
+        try:
+            buffer = bytearray(3)
+            with self.i2c_device as device:
+                device.readinto(buffer)
+            value = (buffer[0] << 16) | (buffer[1] << 8) | buffer[2]
+            return value
+        except Exception as error:
+            raise ValueError("Failed to read time register: ", error) from error

examples/s35710_simpletest.py

@@ -1,4 +1,26 @@
-# SPDX-FileCopyrightText: 2017 Scott Shawcroft, written for Adafruit Industries
 # SPDX-FileCopyrightText: Copyright (c) 2024 Liz Clark for Adafruit Industries
 #
-# SPDX-License-Identifier: Unlicense
+# SPDX-License-Identifier: MIT
+
+import time
+import board
+import adafruit_s35710
+
+i2c = board.I2C()
+
+timer = adafruit_s35710.Adafruit_S35710(i2c)
+
+timer.alarm = 5
+print(f"The S-35710 alarm is set for {timer.alarm} seconds")
+
+countdown = timer.alarm - timer.clock
+
+while True:
+    print(f"The S-35710 clock is {timer.clock}")
+    countdown = timer.alarm - timer.clock
+    if countdown == 0:
+        timer.alarm = 5
+        print("Alarm reached! Resetting..")
+    else:
+        print(f"The alarm will expire in {countdown} seconds")
+    time.sleep(1)