make scopevis.py example program really useful

Signed-off-by: Martin <[email protected]>

CHANGELOG

@@ -1,3 +1,4 @@
+2024-05-03: upversion 2.10.8; update examples and doc [ac44d00]
 2024-05-02: more documentation for example programs [fb8e531]
 2024-05-01: fix set_cal_out_freq_6022.py; some minor updates [3560cbd]
 2024-02-25: add fx2lib lib files [852f574]

PyHT6022/LibUsbScope.py

@@ -551,7 +551,7 @@ def read_data(self, data_size=0x400, raw=False, timeout=0):
         if self.num_channels == 2:
             chdata = data[::2], data[1::2]
         else:
-            chdata = data, ''
+            chdata = data, b''
         if raw:
             return chdata
         else:
@@ -799,10 +799,12 @@ def set_sample_rate(self, rate_index, timeout=0):
         :param rate_index: The rate_index. These are the keys for the SAMPLE_RATES dict for the Oscilloscope object.
                            Common rate_index values and actual sample rate per channel:
                            102 <->  20 kS/s
+                           103 <->  32 kS/s
                            104 <->  40 kS/s
                            105 <->  50 kS/s
                            106 <->  64 kS/s
                            110 <-> 100 kS/s
+                           113 <-> 128 kS/s
                            120 <-> 200 kS/s
                            140 <-> 400 kS/s
                            150 <-> 500 kS/s

examples/capture_6022.py

@@ -178,7 +178,7 @@ def pcb( ch1_data, ch2_data ):
             pcb.av1 /= downsample
             pcb.av2 /= downsample
             if pcb.timestep < sample_time:
-                line = "{:>10.6f}, {:>10.5f}, {:>10.5f}\n".format( pcb.timestep, pcb.av1, pcb.av2 )
+                line = f"{pcb.timestep:>10.6f}, {pcb.av1:>10.5f}, {pcb.av2:>10.5f}\n"
                 if german:
                     line=line.replace( ',', ';' ).replace( '.', ',' )
                 outfile.write( line )
@@ -187,7 +187,7 @@ def pcb( ch1_data, ch2_data ):
     else: # write out every sample
         for ch1_value, ch2_value in zip( ch1_scaled, ch2_scaled ): # merge CH1 & CH2
             if pcb.timestep < sample_time:
-                line = "{:>10.6f}, {:>10.5f}, {:>10.5f}\n".format( pcb.timestep, ch1_value, ch2_value )
+                line = f"{pcb.timestep:>10.6f}, {ch1_value:>10.5f}, {ch2_value:>10.5f}\n"
                 if german:
                     line=line.replace( ',', ';' ).replace( '.', ',' )
                 outfile.write( line )
@@ -227,7 +227,7 @@ def pcb( ch1_data, ch2_data ):
 
 if downsample: # calculate the effective sample rate
     sample_rate = sample_rate / 256 / downsample
-line = "\rCaptured data for {} second(s) @ {} S/s\n".format( sample_time, sample_rate)
+line = f"\rCaptured data for {sample_time} second(s) @ {sample_rate} S/s\n"
 if german:
     line=line.replace( ',', ';' ).replace( '.', ',' )
 sys.stderr.write( line )
@@ -245,11 +245,11 @@ def pcb( ch1_data, ch2_data ):
 rms1 = math.sqrt( rms1 )
 rms2 = math.sqrt( rms2 )
 
-line = "CH1: DC = {:8.4f} V, AC = {:8.4f} V, RMS = {:8.4f} V\n".format( dc1, ac1, rms1 )
+line = f"CH1: DC = {dc1:8.4f} V, AC = {ac1:8.4f} V, RMS = {rms1:8.4f} V\n"
 if german:
     line=line.replace( ',', ';' ).replace( '.', ',' )
 sys.stderr.write( line )
-line = "CH2: DC = {:8.4f} V, AC = {:8.4f} V, RMS = {:8.4f} V\n".format( dc2, ac2, rms2 )
+line = f"CH2: DC = {dc2:8.4f} V, AC = {ac2:8.4f} V, RMS = {rms2:8.4f} V\n"
 if german:
     line=line.replace( ',', ';' ).replace( '.', ',' )
 sys.stderr.write( line )

examples/scopevis.py

@@ -6,54 +6,110 @@
 import pylab
 import time
 import sys
+import argparse
 
-def apply_data_smoothing(data, window=1):
-    new_data = data[:window]
-    for i, point in enumerate(data[window:-window]):
-        new_data.append(sum(data[i-window:i+window+1])/(2*window+1))
-    new_data.extend(data[-window:])
-    return new_data
+samplerates = ( 20, 32, 50, 64, 100, 128, 200, 500, 1000, 2000, 4000, 8000, 10000 )
+samplerate_help = "sample rate in kS/s ("
+for samplerate in samplerates:
+    samplerate_help +=  str( samplerate ) + ", "
+samplerate_help += f"default: {samplerates[0]})"
 
+gains = ( 1, 2, 5, 10 )
+gain_help = "channel gain ("
+for gain in gains:
+    gain_help +=  str( gain ) + ", "
+gain_help += f"default: {gains[0]})"
 
-sample_rate_index = 1
-voltage_range = 0x01
-cal_freq = 10
+# construct the argument parser and parse the arguments
+ap = argparse.ArgumentParser(
+    prog='scopevis.py',
+    description='Capture data from Hantek6022' )
+ap.add_argument( "--ac1", action = "store_true", default = False, help = "AC coupling for CH1" )
+ap.add_argument( "--ac2", action = "store_true", default = False, help = "AC coupling for CH2" )
+ap.add_argument( "-b", "--blocks", type = int, default = 20, help="number of 1K sample blocks, default: 20" )
+ap.add_argument( "--ch1", type = int, default = gains[0], help=f"select gain for ch1 (1, 2, 5, 10, default: {gains[0]})" )
+ap.add_argument( "--ch2", type = int, default = 0, help="sample also ch2 with gain 1, 2, 5, 10" )
+ap.add_argument( "-f", "--frequency", type = int, default = 0, help="set cal out frequency in Hz" )
+ap.add_argument( "-s", "--samplerate", type = int, default = samplerates[0], help=samplerate_help )
 
-# skip first samples due to unstable xfer
-skip = 2 * 0x400 
-data_points = skip + 20 * 0x400
+options = ap.parse_args()
+argerr = False
+if options.ch1 and options.ch1 not in gains:
+    print( "error, ch1 gain must be one of:", gains )
+    argerr = True
+if options.ch2 and options.ch2 not in gains:
+    print( "error, ch2 gain must be one of:", gains )
+    argerr = True
+if options.samplerate not in samplerates:
+    print( "error, rate must be one of:", samplerates )
+    argerr = True
+if argerr:
+    sys.exit()
+
+data_points = options.blocks * 1024
+
+# skip first 2K samples due to unstable xfer
+skip = 2 * 1024
+data_points += skip
 
 scope = Oscilloscope()
 scope.setup()
 scope.open_handle()
-scope.set_sample_rate(sample_rate_index)
-scope.set_ch1_voltage_range(voltage_range)
-scope.set_ch1_ac_dc( scope.DC )
-scope.set_calibration_frequency( cal_freq )
 
-time.sleep( 1 )
+# upload correct firmware into device's RAM
+if (not scope.is_device_firmware_present):
+    scope.flash_firmware()
+
+# calculate and set the sample rate ID from real sample rate value
+if options.samplerate < 1e3:
+    sample_id = int( round( 100 + options.samplerate / 10 ) ) # 20k..500k -> 102..150
+else:
+    sample_id = int( round( options.samplerate / 1e3 ) ) # 1000k -> 1
+
+scope.set_sample_rate( sample_id )
+
+if options.ch1:
+    scope.set_ch1_voltage_range( options.ch1 )
+if options.ac1:
+    scope.set_ch1_ac_dc( scope.AC )
+else:
+    scope.set_ch1_ac_dc( scope.DC )
+
+if options.ch2:
+    scope.set_num_channels( 2 )
+    scope.set_ch2_voltage_range( options.ch2 )
+    if options.ac2:
+        scope.set_ch2_ac_dc( scope.AC )
+    else:
+        scope.set_ch2_ac_dc( scope.DC )
+else:
+    scope.set_ch2_voltage_range( 1 )
 
-ch1_data, _ = scope.read_data(data_points)#,raw=True)#timeout=1)
+# read and apply calibration values from EEPROM
+calibration = scope.get_calibration_values()
 
-voltage_data = scope.scale_read_data(ch1_data[skip:], voltage_range)
-timing_data, _ = scope.convert_sampling_rate_to_measurement_times(data_points-skip, sample_rate_index)
+if options.frequency:
+    scope.set_calibration_frequency( options.frequency )
+
+time.sleep( 0.1 )
+
+
+ch1_data, ch2_data = scope.read_data(data_points)#,raw=True)#timeout=1)
+
+if options.ch1:
+    voltage_data1 = scope.scale_read_data(ch1_data[skip:], options.ch1, channel=1 )
+if options.ch2:
+    voltage_data2 = scope.scale_read_data(ch2_data[skip:], options.ch2, channel=2 )
+timing_data, rate_label = scope.convert_sampling_rate_to_measurement_times(data_points-skip, sample_id)
 scope.close_handle()
 
-if len(timing_data) != len(voltage_data):
-    w = sys.stderr.write
-    w('data lengths differ!\n')
-    w(str([(s,len(eval(s+'_data')))for s in 'timing voltage'.split()]))
-    w('\n')
-    exit(1)
-
-# store the data
-with open('/tmp/scopevis.dat', 'wt') as ouf:
-    ouf.write('\n'.join('{:8f}'.format(v) for v in voltage_data))
-    ouf.write('\n')
-
-pylab.title('Scope Visualization Example')
-pylab.plot(timing_data, voltage_data, color='#009900', label='Raw Trace')
-pylab.plot(timing_data, apply_data_smoothing(voltage_data, window=3), color='#0033CC', label='Smoothed Trace')
+
+pylab.title( f'{options.blocks}K samples @ {rate_label}')
+if options.ch1:
+    pylab.plot(timing_data, voltage_data1, color='#C00000', label='CH1')
+if options.ch2:
+    pylab.plot(timing_data, voltage_data2, color='#0000C0', label='CH2')
+
 pylab.xlabel('Time (s)')
 pylab.ylabel('Voltage (V)')
 pylab.grid()