Updated the ACM1219 driver

frappy_psi/ACM1219.py

@@ -23,7 +23,7 @@ from frappy.core import Readable, Parameter, FloatRange, HasIO, StringIO, Proper
 
 class ACM1219IO(StringIO):
     """communication with ACM1219"""
-    end_of_line = '\n'
+    end_of_line = ('\r\n', '\r') # ('\n', '\r') ('\r\n', '\r')
     wait_before = 0.05
     identification = [('*IDN?', r'.*')]
 
@@ -150,6 +150,43 @@ class Force(Readable):
         force = alpha / (cap - self.Cp) - self.f0 - f0_T
 
         return force
+    
+
+class Stress(Readable):
+
+    # attached classes for displacement
+    force = Attached()
+
+    # modifying a property of inherited parameters (unit is propagated to the FloatRange datatype)
+    value = Parameter('stress', FloatRange(None, None, unit='GPa'), readonly=True)
+    area = Parameter('cross sectional area of sample in mm^2', FloatRange(None, None, unit='mm^2'), readonly=False)
+
+    def read_value(self):
+        return self.force.value / self.area / 1000
 
 
+class Strain(Readable):
+
+    # attached classes for displacement
+    displacement = Attached()
+
+    # modifying a property of inherited parameters (unit is propagated to the FloatRange datatype)
+    value = Parameter('strain', FloatRange(None, None, unit='m/m'), readonly=True)
+    L = Parameter('length of sample in mm', FloatRange(None, None, unit='mm'), readonly=False)
+
+    def read_value(self):
+        return self.displacement.value / (1000*self.L)
+    
+
+class YoungsModulus(Readable):
+
+    # attached classes for displacement
+    stress = Attached()
+    strain = Attached()
+
+    # modifying a property of inherited parameters (unit is propagated to the FloatRange datatype)
+    value = Parameter('Young\'s modulus', FloatRange(None, None, unit='GPa'), readonly=True)
+
+    def read_value(self):
+        return self.stress.value / self.strain.value