feat!: 💥 rename HIDRO/ION Low Flow status keys to Low + add Redox Low (#40)

- rename decoded status key "HIDRO Low Flow" to "HIDRO Low"
- rename decoded status key "ION Low Flow" to "ION Low"
- bit 1 (0x0002) of MBF_HIDRO_STATUS / MBF_ION_STATUS signals the module
  cannot reach the configured production setpoint, not a flow problem;
  flow indicators live on bits 3 (FL1) and 9 (FL2)
- add "Redox Low" key (bit 0x0080) to decode_ph_rx_cl_cd_status_bits,
  emitted only for unit=Redox; brings symmetry with HIDRO/ION Low
- drop stale comment about HIDRO bit 15 (Tasmota MBMSK_HIDRO_STATUS does
  not define it; the decoded dict already omitted it)

Resolves #33

Author: svasek

src/neopool_modbus/status_mask.py

@@ -85,6 +85,7 @@ def decode_ph_rx_cl_cd_status_bits(status: int | None, unit: str) -> dict[str, b
     """Decode the status bits for pH, Redox, Chlorine, and Conductivity sensors."""
     # Status bits are 16 bits, where each bit represents a status flag
     # Bit 3:  Flow sensor problem
+    # Bit 7:  Low - the module cannot reach the configured setpoint (Redox only)
     # Bit 10: Module control status (flow detection control)
     # Bit 11: Acid pump active (pH only; depends on MBF_PAR_PH_ACID_RELAY_GPIO)
     # Bit 12: Pump active (base pump for pH; dosing pump for Rx/CL/CD)
@@ -104,14 +105,17 @@ def decode_ph_rx_cl_cd_status_bits(status: int | None, unit: str) -> dict[str, b
     # Bit 11 is the acid pump - only meaningful for the pH module
     if unit == "pH":
         result[f"{unit} acid pump active"] = bool(status & 0x0800)
+    # Bit 7 signals a low-production alarm - only defined for the Redox module
+    if unit == "Redox":
+        result[f"{unit} Low"] = bool(status & 0x0080)
     return result
 
 
 def decode_ion_status_bits(status: int | None) -> dict[str, bool]:
     """Decode the status bits for ION sensor."""
     # Status bits are 16 bits, where each bit represents a status flag
     # Bit 0: ION On Target
-    # Bit 1: ION Low Flow
+    # Bit 1: ION Low - the ionization cannot reach the configured setpoint
     # Bit 2: ION Reserved
     # Bit 3: ION Program time exceeded
     # Bit 12: ION in dead time
@@ -123,7 +127,7 @@ def decode_ion_status_bits(status: int | None) -> dict[str, bool]:
         return {}
     return {
         "ION On Target": bool(status & 0x0001),
-        "ION Low Flow": bool(status & 0x0002),
+        "ION Low": bool(status & 0x0002),
         "ION Reserved": bool(status & 0x0004),
         "ION Program time exceeded": bool(status & 0x0008),
         "ION in dead time": bool(status & 0x1000),
@@ -136,7 +140,7 @@ def decode_hidro_status_bits(status: int | None) -> dict[str, bool]:
     """Decode the status bits for HIDRO sensor."""
     # Status bits are 16 bits, where each bit represents a status flag
     # Bit 0: HIDRO On Target
-    # Bit 1: HIDRO Low Flow
+    # Bit 1: HIDRO Low - the hydrolysis cannot reach the configured setpoint
     # Bit 2: HIDRO Reserved
     # Bit 3: HIDRO Cell Flow FL1 (if present)
     # Bit 4: Pool Cover (cover input active)
@@ -149,13 +153,11 @@ def decode_hidro_status_bits(status: int | None) -> dict[str, bool]:
     # Bit 12: HIDRO in dead time
     # Bit 13: HIDRO in Pol1
     # Bit 14: HIDRO in Pol2
-    # Bit 15: HIDRO measurement module detected
-    # Note: HIDRO measurement module is always detected if HIDRO sensor is present
     if status is None:
         return {}
     return {
         "HIDRO On Target": bool(status & 0x0001),
-        "HIDRO Low Flow": bool(status & 0x0002),
+        "HIDRO Low": bool(status & 0x0002),
         "HIDRO Reserved": bool(status & 0x0004),
         "HIDRO Cell Flow FL1": bool(status & 0x0008),  # if present
         "Pool Cover": bool(status & 0x0010),

tests/test_status_mask.py

@@ -98,6 +98,20 @@ def test_decode_ph_rx_cl_cd_status_bits_no_acid_for_non_ph():
     assert "Redox pump active" in result
 
 
+def test_decode_ph_rx_cl_cd_status_bits_redox_low():
+    """Bit 7 (0x0080) is the Redox Low alarm, only defined for Redox."""
+    result = decode_ph_rx_cl_cd_status_bits(0x0080, "Redox")
+    assert result["Redox Low"] is True
+
+
+@pytest.mark.parametrize("unit", ["pH", "Chlorine", "Conductivity"])
+def test_decode_ph_rx_cl_cd_status_bits_low_key_only_for_redox(unit):
+    """The Low key is emitted only for Redox, never for pH/CL/CD."""
+    # Every bit set - if Low ever leaked into other units it would show up.
+    result = decode_ph_rx_cl_cd_status_bits(0xFFFF, unit)
+    assert f"{unit} Low" not in result
+
+
 def test_decode_ion_status_bits_basic():
     # ION On Target, ION in Pol2
     status = 0x4001
@@ -107,6 +121,13 @@ def test_decode_ion_status_bits_basic():
     assert result["ION in dead time"] is False
 
 
+def test_decode_ion_status_bits_low_bit():
+    # Bit 1 represents low production (cannot reach setpoint), not flow.
+    result = decode_ion_status_bits(0x0002)
+    assert result["ION Low"] is True
+    assert "ION Low Flow" not in result
+
+
 def test_decode_ion_status_bits_none():
     assert decode_ion_status_bits(None) == {}
 
@@ -121,6 +142,15 @@ def test_decode_hidro_status_bits_basic():
     assert result["Pool Cover"] is False
 
 
+def test_decode_hidro_status_bits_low_bit():
+    # Bit 1 represents low production (cannot reach setpoint), not flow.
+    # Flow indicators live on bits 3 (FL1) and 9 (FL2).
+    result = decode_hidro_status_bits(0x0002)
+    assert result["HIDRO Low"] is True
+    assert result["HIDRO Cell Flow FL1"] is False
+    assert "HIDRO Low Flow" not in result
+
+
 def test_decode_hidro_status_bits_none():
     assert decode_hidro_status_bits(None) == {}