Changeset 4610

Timestamp:

08/26/08 04:54:54 (5 years ago)

Author:

werner

Message:

Support for full waveform retrieval with DS1000CD. This allows decoding of
SPI (and SD) sequences of up to about 50kbits.

• lib/scope.py (scale_125): improved tolerance against rounding errors
• lib/scope.py: added full-depth retrieval for analog and digital waves
• lib/scope.py: give credit to rew's Rigol interface program
• lib/scope.py: send parameters of horizontal system only in non-exponential format (exponents confuse the Rigol)

File:

• developers/werner/ahrt/host/tmc/lib/scope.py (modified) (8 diffs)

developers/werner/ahrt/host/tmc/lib/scope.py

@@ -4 +4 @@
 # 
 
-# Found screen dump algorithm here:
+# Found Rigol screen dump algorithm here:
 # http://www.circuitsonline.net/forum/view/message/652573#652573
+#
+# Rigol data retrieval is heavily based on
+# http://prive.bitwizard.nl/rigol/rigol-0.1rew3.tgz
+#
 
 #
@@ -24 +28 @@
 
 def scale_125(n = None, fuzz = None, min = None, max = None):
+    epsilon = 1e-15
     res = None
     for e in range(-9, 1+1):
@@ -34 +39 @@
             if n is not None and r >= n*(1-fuzz) and r <= n*(1+fuzz):
                 return s
-            if min is not None and r >= min:
+            if min is not None and r >= min-epsilon:
                 return s
-            if max is not None and r <= max:
+            if max is not None and r <= max+epsilon:
                 res = s
     if res is not None:
@@ -108 +113 @@
 
     def wave(self, start = None, end = None, step = None):
-        width = self.scope.div_hor*self.scope.hor.scale
-        if start is None and end is None:
-            start = self.scope.hor.pos
-        if start is not None and end is None:
-            end = start+width
-        elif start is None and end is not None:
-            start = end-width
-        if step is None:
-            return self.scope.download_wave(self, start, end, None)
-        else:
-            # @@@ put setting the horizontal system into download_wave
-            if step*self.scope.sampling_rate() < 1:
-                raise hell
-            span = step*self.scope.samples_per_div*self.scope.div_hor
-            if False and span >= start-end:
-                return self.scope.download_wave(self, start, end, None)
-            else:
-                scale = float(scale_125(max = step*self.scope.samples_per_div))
-                orig_pos = self.scope.hor.pos
-                orig_scale = self.scope.hor.scale
-                self.scope.hor.scale = scale
-                span = self.scope.div_hor*self.scope.hor.scale
-                wave = analog_wave()
-                pos = start
-                while pos < end:
-                    self.scope.hor.pos = pos
-                    wave.extend(self.scope.download_wave(self, pos, pos+span,
-                      None))
-                    pos += span
-                self.scope.hor.pos = orig_pos
-                self.scope.hor.scale = orig_scale
-                return wave
+        # @@@ move start and end adjustment here !
+        return self.scope.download_wave(self, start, end, step)
 
 
@@ -150 +125 @@
         self.scope = scope
         self.pos = setting(scope, ":TIM:OFFS",
-          lambda x: float(x))
+          lambda x: float(x),
+          lambda x: "%.9f" % x)
         self.scale = setting(scope, ":TIM:SCAL",
-          lambda x: float(x))
+          lambda x: float(x),
+          lambda x: "%.9f" % x)
         self.forget()
 
@@ -265 +242 @@
 
 
+def rigol_wave(scope, start, end, step, query, merge, fn, *args):
+    wave = None
+    orig_pos = scope.hor.pos
+    orig_scale = scope.hor.scale
+
+    width = scope.div_hor*orig_scale
+    if start is None:
+        start = orig_pos-width/2
+    if end is None:
+        end = orig_pos+width/2
+    if step is None:
+        step = 1/scope.sampling_rate()
+
+    scope.hor.scale = float(scale_125(max = step*scope.samples_per_div))
+    while start < end:
+        scope.hor.pos = start+6*scope.hor.scale
+        data = scope.query(query)
+        data = fn(data, scope.hor.pos, scope.hor.scale, *args)
+        if wave is None:
+            wave = data
+        else:
+            merge(wave, data)
+        start += 12*scope.hor.scale
+
+    scope.hor.pos = orig_pos
+    scope.hor.scale = orig_scale
+    return wave
+
+
+def rigol_extend_la(a, b):
+    i = 0
+    while i != 16:
+        a[i].extend(b[i])
+        i += 1
+
+
 def rigol_to_ppm(s):
     lut = []
@@ -283 +296 @@
     div_hor = 12
     div_vert = 10
-    samples_per_div = 600       #@@@ not exactly true. needs more investigation
+    samples_per_div = 50
 
     def __init__(self):
@@ -322 +335 @@
             if self.ch[n] == channel:
                 c_num = n+1
-        data = self.query(":WAV:DATA? CHAN"+str(c_num))
-        return rigol_channel_data(data, self.hor.pos, self.hor.scale,
-           channel.pos, channel.scale)
+        return rigol_wave(self, start, end, step,
+          ":WAV:DATA? CHAN"+str(c_num),
+          lambda a, b: a.extend(b),
+          rigol_channel_data, channel.pos, channel.scale)
 
     # experimental
 
-    def download_la(self):
-        data = self.query(":WAV:DATA? DIG")
-        return rigol_la_data(data, self.hor.pos, self.hor.scale)
+    def download_la(self, start = None, end = None, step = None):
+        return rigol_wave(self, start, end, step,
+          ":WAV:DATA? DIG",
+          rigol_extend_la, rigol_la_data)
 
     def sampling_rate(self):