Add instrument interface protocols

src/py_dvt_ate/instruments/__init__.py

@@ -7,3 +7,15 @@ This package provides everything needed to communicate with lab instruments:
 - Instrument drivers
 - Factory for creating configured instrument sets
 """
+
+from py_dvt_ate.instruments.interfaces import (
+    IMultimeter,
+    IPowerSupply,
+    IThermalChamber,
+)
+
+__all__ = [
+    "IThermalChamber",
+    "IPowerSupply",
+    "IMultimeter",
+]

src/py_dvt_ate/instruments/interfaces.py

@@ -0,0 +1,362 @@
+"""Instrument interface protocols.
+
+This module defines the Hardware Abstraction Layer (HAL) interfaces for all
+laboratory instruments used in DVT testing. These protocols allow test code
+to be written against abstract interfaces rather than concrete implementations,
+enabling seamless switching between simulated and real hardware.
+
+The interfaces use ABC (Abstract Base Classes) for maximum type safety and
+explicit interface implementation. All drivers must inherit from these base
+classes and implement all abstract methods.
+"""
+
+from abc import ABC, abstractmethod
+
+
+class IThermalChamber(ABC):
+    """Hardware abstraction for thermal chambers.
+
+    Defines the interface for controlling environmental temperature during
+    thermal characterisation tests. Implementations may be virtual instruments
+    (simulators) or real hardware drivers.
+
+    Temperature units are always degrees Celsius.
+    """
+
+    @abstractmethod
+    def set_temperature(self, setpoint: float) -> None:
+        """Set the chamber temperature setpoint.
+
+        Args:
+            setpoint: Target temperature in degrees Celsius.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If command fails or instrument reports error.
+        """
+        pass
+
+    @abstractmethod
+    def get_temperature(self) -> float:
+        """Get the actual chamber temperature.
+
+        Returns:
+            Current chamber air temperature in degrees Celsius.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+        """
+        pass
+
+    @abstractmethod
+    def get_setpoint(self) -> float:
+        """Get the current temperature setpoint.
+
+        Returns:
+            Current target temperature in degrees Celsius.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+        """
+        pass
+
+    @abstractmethod
+    def is_stable(self) -> bool:
+        """Check if chamber temperature is stable.
+
+        Temperature is considered stable when it has settled within
+        the instrument's configured stability threshold of the setpoint
+        for a minimum dwell time.
+
+        Returns:
+            True if temperature is stable, False if still settling.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+        """
+        pass
+
+    @abstractmethod
+    def wait_until_stable(
+        self, timeout: float = 300.0, poll_interval: float = 1.0
+    ) -> bool:
+        """Wait until chamber temperature stabilises.
+
+        Polls the stability status at regular intervals until stable
+        or timeout is reached. This is a blocking call.
+
+        Args:
+            timeout: Maximum time to wait in seconds. Default 300s (5 minutes).
+            poll_interval: Time between stability checks in seconds. Default 1s.
+
+        Returns:
+            True if temperature stabilised within timeout, False if timed out.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If communication fails.
+            ValueError: If timeout or poll_interval are invalid.
+        """
+        pass
+
+    @abstractmethod
+    def set_ramp_rate(self, rate: float) -> None:
+        """Set the temperature ramp rate.
+
+        Controls how quickly the chamber changes temperature when moving
+        to a new setpoint. Slower ramp rates reduce thermal shock to DUT.
+
+        Args:
+            rate: Ramp rate in degrees Celsius per minute.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If command fails or instrument reports error.
+            ValueError: If rate is negative or exceeds instrument limits.
+        """
+        pass
+
+
+class IPowerSupply(ABC):
+    """Hardware abstraction for programmable power supplies.
+
+    Defines the interface for controlling DC power supplies during electrical
+    characterisation tests. Implementations may be virtual instruments
+    (simulators) or real hardware drivers.
+
+    Voltage units are always volts (V).
+    Current units are always amps (A).
+    """
+
+    @abstractmethod
+    def set_voltage(self, channel: int, voltage: float) -> None:
+        """Set the output voltage setpoint.
+
+        Args:
+            channel: Output channel number (1-based indexing).
+            voltage: Target voltage in volts.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If command fails or instrument reports error.
+            ValueError: If channel is invalid or voltage out of range.
+        """
+        pass
+
+    @abstractmethod
+    def get_voltage(self, channel: int) -> float:
+        """Get the voltage setpoint.
+
+        Returns the programmed voltage, not the measured output voltage.
+        Use measure_voltage() to get the actual output voltage.
+
+        Args:
+            channel: Output channel number (1-based indexing).
+
+        Returns:
+            Current voltage setpoint in volts.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+            ValueError: If channel is invalid.
+        """
+        pass
+
+    @abstractmethod
+    def set_current_limit(self, channel: int, current: float) -> None:
+        """Set the current limit.
+
+        The supply will operate in constant voltage mode until output current
+        reaches this limit, then transition to constant current mode.
+
+        Args:
+            channel: Output channel number (1-based indexing).
+            current: Current limit in amps.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If command fails or instrument reports error.
+            ValueError: If channel is invalid or current out of range.
+        """
+        pass
+
+    @abstractmethod
+    def get_current_limit(self, channel: int) -> float:
+        """Get the current limit.
+
+        Args:
+            channel: Output channel number (1-based indexing).
+
+        Returns:
+            Current limit in amps.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+            ValueError: If channel is invalid.
+        """
+        pass
+
+    @abstractmethod
+    def measure_voltage(self, channel: int) -> float:
+        """Measure the actual output voltage.
+
+        Args:
+            channel: Output channel number (1-based indexing).
+
+        Returns:
+            Measured output voltage in volts.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+            ValueError: If channel is invalid.
+        """
+        pass
+
+    @abstractmethod
+    def measure_current(self, channel: int) -> float:
+        """Measure the actual output current.
+
+        Args:
+            channel: Output channel number (1-based indexing).
+
+        Returns:
+            Measured output current in amps.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+            ValueError: If channel is invalid.
+        """
+        pass
+
+    @abstractmethod
+    def enable_output(self, channel: int, enable: bool) -> None:
+        """Enable or disable the output.
+
+        Args:
+            channel: Output channel number (1-based indexing).
+            enable: True to enable output, False to disable.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If command fails or instrument reports error.
+            ValueError: If channel is invalid.
+        """
+        pass
+
+    @abstractmethod
+    def is_output_enabled(self, channel: int) -> bool:
+        """Check if output is enabled.
+
+        Args:
+            channel: Output channel number (1-based indexing).
+
+        Returns:
+            True if output is enabled, False if disabled.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+            ValueError: If channel is invalid.
+        """
+        pass
+
+
+class IMultimeter(ABC):
+    """Hardware abstraction for digital multimeters.
+
+    Defines the interface for making precision measurements with DMMs during
+    electrical characterisation tests. Implementations may be virtual instruments
+    (simulators) or real hardware drivers.
+
+    Voltage units are always volts (V).
+    Current units are always amps (A).
+    Resistance units are always ohms (Ω).
+    """
+
+    @abstractmethod
+    def measure_dc_voltage(self, range: str = "AUTO") -> float:
+        """Measure DC voltage.
+
+        Configures the meter for DC voltage and takes a measurement.
+
+        Args:
+            range: Measurement range. Default "AUTO" for auto-ranging.
+                  Specific ranges depend on instrument capabilities.
+
+        Returns:
+            Measured voltage in volts.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+            ValueError: If range is invalid for this instrument.
+        """
+        pass
+
+    @abstractmethod
+    def measure_dc_current(self, range: str = "AUTO") -> float:
+        """Measure DC current.
+
+        Configures the meter for DC current and takes a measurement.
+
+        Args:
+            range: Measurement range. Default "AUTO" for auto-ranging.
+                  Specific ranges depend on instrument capabilities.
+
+        Returns:
+            Measured current in amps.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+            ValueError: If range is invalid for this instrument.
+        """
+        pass
+
+    @abstractmethod
+    def measure_resistance(self, range: str = "AUTO") -> float:
+        """Measure resistance.
+
+        Configures the meter for resistance and takes a measurement.
+
+        Args:
+            range: Measurement range. Default "AUTO" for auto-ranging.
+                  Specific ranges depend on instrument capabilities.
+
+        Returns:
+            Measured resistance in ohms.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If query fails or instrument reports error.
+            ValueError: If range is invalid for this instrument.
+            NotImplementedError: If instrument does not support resistance.
+        """
+        pass
+
+    @abstractmethod
+    def set_integration_time(self, nplc: float) -> None:
+        """Set the integration time.
+
+        Integration time affects measurement accuracy and speed. Higher
+        values (more power line cycles) provide better noise rejection
+        but take longer to measure.
+
+        Args:
+            nplc: Integration time in number of power line cycles (NPLC).
+                 Typical values: 0.02, 0.2, 1, 10, 100.
+
+        Raises:
+            ConnectionError: If not connected to instrument.
+            IOError: If command fails or instrument reports error.
+            ValueError: If nplc is invalid for this instrument.
+            NotImplementedError: If instrument does not support integration time.
+        """
+        pass