Fixes a bug in vab_square_wave; Fixes a bug in test_measure_with_ohmpi_card_3_15.py

measure.py

@@ -152,7 +152,7 @@ class OhmPiHardware:
         return vab, polarity, rab
 
     def vab_square_wave(self, vab, length, sampling_rate, cycles=3):
-        self._vab_pulses(self, vab, [length]*cycles, sampling_rate)
+        self._vab_pulses(vab, [length]*cycles, sampling_rate)
 
     def _vab_pulse(self, vab, length, sampling_rate=None, polarity=None, append=False):
         """ Gets VMN and IAB from a single voltage pulse

test_measure_with_ohmpi_card_3_15.py

@@ -6,7 +6,7 @@ from OhmPi.measure import OhmPiHardware
 
 k = OhmPiHardware()
 k.vab_square_wave(vab=12, length=1., sampling_rate=k.rx.sampling_rate, cycles=3)
-r = k.readings[:,4]*k.readings[:,2]/k.readings[:,1]
+r = k.readings[:,3]*k.readings[:,2]/k.readings[:,1]
 print(f'Mean resistance: {np.mean(r):.3f} Ohms, Dev. {100*np.std(r)/np.mean(r):.1f} %')
 print(f'sampling rate: {k.rx.sampling_rate:.1f} ms, mean sample spacing: {np.mean(np.diff(k.readings[:,0]))*1000.:.1f} ms')
 change_config('config_default.py', verbose=False)