Tools: added script to decode Saleae CSV capture file

Tools/scripts/logic_decode_channels.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python
+'''
+decode a Saleae logic CSV export file as PWM values. Used for
+testing output values on PWM channels
+'''
+
+import csv, sys
+
+filename = sys.argv[1]
+
+c = open(filename, 'r')
+data = csv.reader(c)
+
+pulse_start = []
+prev_values = []
+pwm = []
+nchannels = 0
+
+for row in data:
+    # skip header
+    if row[0].startswith('Time'):
+        continue
+    changed = False
+
+    if len(row) > nchannels+1:
+        nchannels = len(row)-1
+        while len(pwm) < nchannels:
+            pwm.append(0)
+            pulse_start.append(0)
+            prev_values.append(0)
+
+    # time in microseconds
+    t = int(float(row[0])*1e6)
+
+    # current value of each channel
+    values = [int(row[i]) for i in range(1,len(row))]
+    
+    for c in range(nchannels):
+        if values[c] == 0 and prev_values[c] == 1 and pulse_start[c] != 0:
+            pulse = t - pulse_start[c]
+            if pulse < 10000:
+                pwm[c] = pulse
+                changed = True
+        if values[c] == 1 and prev_values[c] == 0:
+            pulse_start[c] = t
+        prev_values[c] = values[c]
+        
+    if changed:
+        for c in range(nchannels):
+            sys.stdout.write("%4u " % pwm[c])
+        sys.stdout.write("%.3f\n" % float(row[0]))
+