added scanFunction file. Now, the scan is performed with a generator.

myWidgets.py

@@ -14,6 +14,8 @@ import telnetlib
 import os
 from messages import show_warning
 
+import scanFunctions 
+
 #An example of a class
 class anal_control_signal(QWidget):
     _registry = []
@@ -94,15 +96,11 @@ class anal_control_signal(QWidget):
         
     
     def scanEvent(self):
-        if float(self.scan_step) < float(self.scan_sb_start.val)  or float(self.scan_step) > float(self.scan_sb_stop.val):
-            self.scan_direction = (-1) * self.scan_direction
          
-        self.scan_step = self.scan_step + self.scan_direction
+        self.scan_step = next(self.scan_array_gen)
         self.AO.set_out(self.scan_step)
         
-        #print(self.scan_step)
-        
-        
+
     def PbarEvent(self):
         try:
             self.scanpBar.setValue( 100 * float(self.scan_step-float(self.scan_sb_start.val))/float(self.scan_sb_stop.val-self.scan_sb_start.val)   )
@@ -114,12 +112,7 @@ class anal_control_signal(QWidget):
     
     def doScanAction(self):
         
-        
-        #self.scan_direction = -float( (self.scan_sb_stop.val-self.scan_sb_start.val)/self.scan_sb_period.val ) * 5e-3 * 2
-        #self.scan_step = float(self.scan_sb_start.val)
-        
-        
-        
+                        
         if self.ScanTimer.isActive():
             self.ScanTimer.stop()
             self.scan_button.setText('Start scan')
@@ -131,23 +124,18 @@ class anal_control_signal(QWidget):
             
             
         else:
-            b = float(self.scan_sb_stop.val)
-            a = float(self.scan_sb_start.val)
-            dt = 5.0e-3
-            T = float(self.scan_sb_period.val)
-            n = int( T/(2*dt) )
-        
-            self.scan_direction = -abs(b-a)/n # this is the size in voltage of each step
-            self.scan_step = float(self.sb.val) # from here it beggins
             
+            dt = 5.0e-3
+                        
+            self.scan_array = scanFunctions.create_scan_array(self.scan_sb_start.val, self.scan_sb_stop.val, self.scan_sb_period.val, dt)
+            self.scan_array_gen = scanFunctions.yield_scan_array(self.scan_array)
             
             
-            if self.scan_step > b or self.scan_step < a:
+            if self.scan_step > float(self.scan_sb_stop.val) or self.scan_step < float(self.scan_sb_start.val):
                 details = 'Remember remember the fifth of November.' + '\n' + 'Also remember that scan starts from the value of the corresponding spin box'
                 show_warning('Scan can not start outside scan range and scan start should be lower than scan stop', details_text= details)
-            elif n < 5:
-                show_warning('%i steps are too few, you need at least 5 steps' % (n) )
-                pass
+            elif len(self.scan_array) < 5:
+                show_warning('%i steps are too few, you need at least 5 steps' % (len(self.scan_array)) )
             else:
                 self.sb.setEnabled(False)
                 self.scan_button.setStyleSheet("background-color: green")

scanFunctions.py

+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Created on Fri Oct 26 11:24:28 2018
+
+@author: martindrech
+
+Auxiliary functions for performing scans in a cleaner way
+"""
+
+import numpy as np
+
+def create_scan_array(scan_start, scan_stop, scan_period, dt):
+    """
+    Returns the array that represents one period of the scan, including up and down paths of the triangle.  
+    """
+    scan_start = float(scan_start)
+    scan_stop = float(scan_stop)
+    scan_period = float(scan_period)
+    
+    number_of_points = 1 + (scan_period+dt)//(2*dt)
+    scan_array = np.linspace(scan_start, scan_stop, int(number_of_points))
+    
+    return np.concatenate((scan_array, np.flip(scan_array, 0)[1:]))
+
+
+def yield_array(arr):
+    larr = len(arr)
+    cursor = 0
+    while cursor < larr:
+        yield arr[cursor]
+        cursor = cursor + 1
+
+
+def yield_scan_array(arr):
+    while True:
+        yield from yield_array(arr)
+
+
+
+