m-labs · Mar 15, 2015 · Mar 15, 2015 · Mar 15, 2015 · Mar 15, 2015 · Mar 15, 2015
Showing with 227 additions and 0 deletions.

0 artiq/wavesynth/__init__.py

+227 −0 artiq/wavesynth/compute_samples.py
diff --git a/artiq/wavesynth/__init__.py b/artiq/wavesynth/__init__.py
diff --git a/artiq/wavesynth/compute_samples.py b/artiq/wavesynth/compute_samples.py
@@ -0,0 +1,227 @@
+from copy import copy
+from math import cos, pi
+
+import cairoplot
+
+
+class Spline:
+    def __init__(self):
+        self.c = [0.0]
+
+    def set_coefficients(self, c):
+        self.c = copy(c)
+
+    def next(self):
+        r = self.c[0]
+        for i in range(len(self.c)-1):
+            self.c[i] += self.c[i+1]
+        return r
+
+
+class SplinePhase:
+    def __init__(self):
+        self.c = [0.0]
+        self.c0 = 0.0
+
+    def set_coefficients(self, c):
+        self.c = self.c[0:1] + c[1:]
+        self.c0 = c[0]
+
+    def clear(self):
+        self.c[0] = 0.0
+
+    def next(self):
+        r = self.c[0] + self.c0
+        for i in range(len(self.c)-1):
+            self.c[i] = (self.c[i] + self.c[i+1]) % 1.0
+        return r
+
+
+class DDS:
+    def __init__(self):
+        self.amplitude = Spline()
+        self.phase = SplinePhase()
+
+    def next(self):
+        return self.amplitude.next()*cos(2*pi*self.phase.next())
+
+
+class Wave:
+    def __init__(self):
+        self.bias = Spline()
+        self.dds = DDS()
+
+    def next(self):
+        return self.bias.next() + self.dds.next()
+
+
+class TriggerError(Exception):
+    pass
+
+
+class Synthesizer:
+    def __init__(self, nchannels, program):
+        self.channels = [Wave() for _ in range(nchannels)]
+        self.program = program 
+        # line_iter is None: "wait for segment selection" state
+        # otherwise: iterator on the current position in the segment
+        self.line_iter = None
+
+    def trigger(self, selection=None):
+        if selection is None:
+            if self.line_iter is None:
+                raise TriggerError
+        else:
+            if self.line_iter is not None:
+                raise TriggerError
+            self.line_iter = iter(self.program[selection])
+
+        r = [[] for _ in self.channels]
+        while True:
+            line = next(self.line_iter)
+
+            if line["dac_divider"] != 1:
+                raise NotImplementedError
+
+            for channel, channel_data in zip(self.channels,
+                                             line["channel_data"]):
+                if "bias" in channel_data:
+                    channel.bias.set_coefficients(channel_data["bias"])
+                if "dds" in channel_data:
+                    channel.dds.amplitude.set_coefficients(
+                        channel_data["dds"]["amplitude"])
+                    channel.dds.phase.set_coefficients(
+                        channel_data["dds"]["phase"])
+                    if channel_data["dds"]["clear"]:
+                        channel.dds.phase.clear()
+
+            for channel, rc in zip(self.channels, r):
+                for i in range(line["duration"]):
+                    rc.append(channel.next())
+
+            if line["wait_trigger"] and line["jump"]:
+                raise ValueError("Line cannot both jump and wait for trigger")
+            if line["wait_trigger"]:
+                return r
+            if line["jump"]:
+                self.line_iter = None
+                return r
+
+def main():
+    program = [
+        [
+            # segment 0
+            {
+                # segment 0, line 0
+                "dac_divider": 1,
+                "duration": 100,
+                "channel_data": [
+                    {
+                        # channel 0
+                        "dds": {"amplitude": [0.0, 0.0, 0.01],
+                                "phase": [0.0, 0.0, 0.0005],
+                                "clear": False}
+                    }
+                ],
+                "wait_trigger": False,
+                "jump": False
+            },
+            {
+                # segment 1, line 1
+                "dac_divider": 1,
+                "duration": 100,
+                "channel_data": [
+                    {
+                        # channel 0
+                        "dds": {"amplitude": [49.5, 1.0, -0.01],
+                                "phase": [0.0, 0.05, 0.0005],
+                                "clear": False}
+                    }
+                ],
+                "wait_trigger": False,
+                "jump": True
+            },
+        ],
+        [
+            # segment 1
+            {
+                # segment 1, line 0
+                "dac_divider": 1,
+                "duration": 100,
+                "channel_data": [
+                    {
+                        # channel 0
+                        "dds": {"amplitude": [100.0, 0.0, -0.01],
+                                "phase": [0.0, 0.1, -0.0005],
+                                "clear": False}
+                    }
+                ],
+                "wait_trigger": False,
+                "jump": False
+            },
+            {
+                # segment 1, line 1
+                "dac_divider": 1,
+                "duration": 100,
+                "channel_data": [
+                    {
+                        # channel 0
+                        "dds": {"amplitude": [50.5, -1.0, 0.01],
+                                "phase": [0.0, 0.05, -0.0005],
+                                "clear": False}
+                    }
+                ],
+                "wait_trigger": False,
+                "jump": True
+            }
+        ],
+        [
+            # segment 2
+            {
+                # segment 2, line 0
+                "dac_divider": 1,
+                "duration": 84,
+                "channel_data": [
+                    {
+                        # channel 0
+                        "dds": {"amplitude": [100.0],
+                                "phase": [0.0, 0.05],
+                                "clear": False}
+                    }
+                ],
+                "wait_trigger": True,
+                "jump": False
+            },
+            {
+                # segment 2, line 1
+                "dac_divider": 1,
+                "duration": 116,
+                "channel_data": [
+                    {
+                        # channel 0
+                        "dds": {"amplitude": [100.0],
+                                "phase": [0.0, 0.05],
+                                "clear": True}
+                    }
+                ],
+                "wait_trigger": False,
+                "jump": True
+            }
+        ]
+    ]
+
+    x = list(range(600))
+    s = Synthesizer(1, program)
+
+    r = s.trigger(0)
+    y = r[0]
+    r = s.trigger(2)
+    y += r[0]
+    r = s.trigger()
+    y += r[0]
+    r = s.trigger(1)
+    y += r[0]
+    cairoplot.scatter_plot("plot.png", [x, y])
+
+if __name__ == "__main__":
+    main()