Updates

hardware/scope.py

@@ -0,0 +1,133 @@
+"""Keysight DSO80204B scope controller over VXI-11 / SCPI.
+
+Configures channels for MIPI D-PHY probing (50 Ω DC, 19.2× attenuation),
+arms a single trigger, and downloads ASCII waveforms with absolute
+timestamps reconstructed from the preamble.
+
+CRITICAL: All four channels must be DC50 — the 910R+50R divider only gives
+the documented 19.2× ratio with 50 Ω termination.
+"""
+
+from __future__ import annotations
+
+import io
+import logging
+import time
+
+import pandas as pd
+import vxi11
+
+from config import (
+    PROBE_ATTENUATION,
+    SCOPE_CHANNELS,
+    SCOPE_POINTS,
+    SCOPE_TIMEBASE,
+    TRIGGER_CHANNEL,
+    TRIGGER_LEVEL_V,
+    TRIGGER_SLOPE,
+)
+
+log = logging.getLogger(__name__)
+
+
+class ScopeController:
+    def __init__(self, ip: str) -> None:
+        self.ip = ip
+        self._inst = vxi11.Instrument(ip)
+        idn = self._inst.ask("*IDN?").strip()
+        log.info("Scope connected: %s", idn)
+        self.idn = idn
+
+    def setup(self) -> None:
+        i = self._inst
+        i.write("*RST")
+        time.sleep(1.0)
+        i.write(":STOP")
+
+        for label, ch in SCOPE_CHANNELS.items():
+            i.write(f":CHANnel{ch}:DISPlay ON")
+            i.write(f":CHANnel{ch}:INPut DC50")
+            i.write(f":CHANnel{ch}:PROBe {PROBE_ATTENUATION}")
+            i.write(f":CHANnel{ch}:SCALe 0.05")
+            i.write(f":CHANnel{ch}:OFFSet 0.0")
+            i.write(f":CHANnel{ch}:LABel '{label}'")
+
+        i.write(f":TIMebase:SCALe {SCOPE_TIMEBASE:.3E}")
+        i.write(":TIMebase:POSition 0")
+        i.write(":TIMebase:REFerence CENTer")
+
+        i.write(":TRIGger:MODE EDGE")
+        i.write(f":TRIGger:EDGE:SOURce CHANnel{TRIGGER_CHANNEL}")
+        i.write(f":TRIGger:EDGE:SLOPe {TRIGGER_SLOPE}")
+        i.write(f":TRIGger:EDGE:LEVel {TRIGGER_LEVEL_V}")
+        i.write(":TRIGger:SWEep NORMal")
+
+        i.write(":ACQuire:MODE RTIMe")
+        i.write(":ACQuire:INTerpolate ON")
+        i.write(f":ACQuire:POINts {SCOPE_POINTS}")
+
+        i.write(":DISPlay:LAYout STACKed")
+
+    def arm_single(self) -> None:
+        self._inst.write(":SINGle")
+
+    def wait_for_trigger(self, timeout_s: float = 30.0) -> bool:
+        deadline = time.monotonic() + timeout_s
+        while time.monotonic() < deadline:
+            try:
+                ter = int(self._inst.ask(":TER?").strip())
+            except ValueError:
+                ter = 0
+            if ter == 1:
+                return True
+            time.sleep(0.1)
+        return False
+
+    def _read_preamble(self, channel: int) -> dict:
+        self._inst.write(f":WAVeform:SOURce CHANnel{channel}")
+        raw = self._inst.ask(":WAVeform:PREamble?").strip()
+        parts = raw.split(",")
+        return {
+            "format": int(parts[0]),
+            "type": int(parts[1]),
+            "points": int(parts[2]),
+            "count": int(parts[3]),
+            "x_increment": float(parts[4]),
+            "x_origin": float(parts[5]),
+            "x_reference": float(parts[6]),
+            "y_increment": float(parts[7]),
+            "y_origin": float(parts[8]),
+            "y_reference": float(parts[9]),
+        }
+
+    def download_waveform(self, channel: int) -> pd.DataFrame:
+        preamble = self._read_preamble(channel)
+
+        self._inst.write(":WAVeform:FORMat ASCii")
+        self._inst.write(":WAVeform:STReaming ON")
+        self._inst.write(f":WAVeform:SOURce CHANnel{channel}")
+        raw = self._inst.ask(":WAVeform:DATA?")
+
+        if raw.startswith("#"):
+            n_digits = int(raw[1])
+            raw = raw[2 + n_digits :]
+
+        voltages = pd.read_csv(io.StringIO(raw), header=None).iloc[0].astype(float).values
+        n = len(voltages)
+
+        x_inc = preamble["x_increment"]
+        x_origin = preamble["x_origin"]
+        times = x_origin + x_inc * pd.Series(range(n), dtype="float64")
+
+        return pd.DataFrame({"time_s": times, "voltage_v": voltages})
+
+    def download_all(self) -> dict[str, pd.DataFrame]:
+        return {
+            label: self.download_waveform(ch) for label, ch in SCOPE_CHANNELS.items()
+        }
+
+    def close(self) -> None:
+        try:
+            self._inst.close()
+        except Exception:
+            pass