ionopimax: Add LogVoltageInput

frappy_psi/ionopimax.py

@@ -20,6 +20,7 @@
 
 from frappy.core import Readable, Writable, Parameter, BoolType, StringType,\
     FloatRange, Property, TupleOf, ERROR, IDLE
+from math import log
 
 
 class Base:
@@ -74,6 +75,15 @@ class VoltageInput(AnalogInput):
         super().initModule()
         self.write(f'{self.addr}_mode','U')
 
+class LogVoltageInput(VoltageInput):
+    
+    def read_value(self):
+        x0, x1 = self.rawrange
+        y0, y1 = self.valuerange
+        self.x = self.read(self.addr, self.scale)
+        a = (x1-x0)/log(y1/y0,10)
+        return 10**((self.x-x1)/a)*y1
+    
     
 class CurrentInput(AnalogInput):
     scale = 1e6