fix: fix 'configure_pin_six_as_alert()' and provide unit tests

feeph/emc2101/core.py

@@ -173,10 +173,10 @@ def configure_pin_six_as_alert(self) -> bool:
         with BurstHandler(i2c_bus=self._i2c_bus, i2c_adr=self._i2c_adr) as bh:
             cfg_register_value = bh.read_register(0x03)
             if cfg_register_value is not None:
-                bh.write_registers(0x03, cfg_register_value & 0b1111_1011)
+                bh.write_register(0x03, cfg_register_value & 0b1111_1011)
                 # clear spin up behavior settings
                 # (spin up is unavailable when pin 6 is in alert mode),
-                bh.write_registers(0x4B, 0b0000_0000)
+                bh.write_register(0x4B, 0b0000_0000)
                 return True
             else:
                 LH.error("Unable to read config register!")

tests/test_emc2101.py

@@ -0,0 +1,79 @@
+#!/usr/bin/env python3
+"""
+perform PWM related tests
+
+use simulated device:
+  pdm run pytest
+use hardware device:
+  TEST_EMC2101_CHIP=y pdm run pytest
+"""
+
+import os
+import unittest
+
+# modules board and busio provide no type hints
+import board  # type: ignore
+import busio  # type: ignore
+from feeph.i2c import BurstHandler, EmulatedI2C
+
+import feeph.emc2101.core as sut  # sytem under test
+
+if os.environ.get('TEST_EMC2101_CHIP', 'n') == 'y':
+    HAS_HARDWARE = True
+else:
+    HAS_HARDWARE = False
+
+
+class TestEmc2101(unittest.TestCase):
+
+    def setUp(self):
+        self.i2c_adr = 0x4C
+        if HAS_HARDWARE:
+            self.i2c_bus = busio.I2C(scl=board.SCL, sda=board.SDA)
+        else:
+            # initialize read/write registers
+            registers = sut.DEFAULTS.copy()
+            # add readonly registers
+            registers[0x00] = 0x14  # chip temperature
+            registers[0x01] = 0x1B  # external sensor temperature (high byte)
+            registers[0x02] = 0x00  # status register
+            registers[0x0F] = 0x00  # write only register, trigger temperature conversion
+            registers[0x10] = 0xE0  # external sensor temperature (low byte)
+            registers[0x46] = 0xFF  # tacho reading (low byte)
+            registers[0x47] = 0xFF  # tacho reading (high byte)
+            registers[0xFD] = 0x16  # product id
+            registers[0xFE] = 0x5D  # manufacturer id
+            registers[0xFF] = 0x02  # revision
+            self.i2c_bus = EmulatedI2C(state={self.i2c_adr: registers})
+        self.emc2101 = sut.Emc2101_core(i2c_bus=self.i2c_bus)
+        # restore original state after each run
+        # (hardware is not stateless)
+        self.emc2101.reset_device_registers()
+
+    def tearDown(self):
+        # nothing to do
+        pass
+
+    # ---------------------------------------------------------------------
+    # circuit-dependent settings
+    # ---------------------------------------------------------------------
+
+    def test_pin_six_as_alert(self):
+        # -----------------------------------------------------------------
+        computed = self.emc2101.configure_pin_six_as_alert()
+        expected = True
+        # -----------------------------------------------------------------
+        self.assertEqual(computed, expected, "Failed to enable alert mode.")
+        with BurstHandler(i2c_bus=self.i2c_bus, i2c_adr=self.i2c_adr) as bh:
+            self.assertEqual(bh.read_register(0x03), 0b0000_0000)
+            self.assertEqual(bh.read_register(0x4B), 0b0000_0000)
+
+    def test_pin_six_as_tacho(self):
+        # -----------------------------------------------------------------
+        computed = self.emc2101.configure_pin_six_as_tacho()
+        expected = True
+        # -----------------------------------------------------------------
+        self.assertEqual(computed, expected, "Failed to enable tacho mode.")
+        with BurstHandler(i2c_bus=self.i2c_bus, i2c_adr=self.i2c_adr) as bh:
+            self.assertEqual(bh.read_register(0x03), 0b0000_0100)
+            self.assertEqual(bh.read_register(0x4B), 0b0011_1111)