1 files changed, 92 insertions, 0 deletions
diff --git a/ebus/model/__init__.py b/ebus/model/__init__.py
new file mode 100644
index 0000000..ecdf3bc
--- /dev/null
+++ b/ebus/model/__init__.py
@@ -0,0 +1,92 @@
+class DataField(object):
+    def __init__(self, name, offset):
+        self.name = name
+        self.offset = offset
+    def value(self,data):
+        raise NotImplemented()
+
+ class Data1b(DataField):
+     """
+    Beispiel für die Berechnung:
+    if ((x & 80h) == 80h) // y negativ
+    y     = - [dez(!x) + 1]
+    else 
+    y     = dez(x)
+    """
+     def value(self,data):
+         x = ord(data[self.offset])
+         if x & 0x80 == 0x80:
+             return (-1) * (0xff^x + 1)
+         else:
+             return x
+
+class Data1c(DataField):
+    def value(self,data):
+        return ord(data[self.offset])/2.0
+                 
+class Data2c(DataField):
+    """
+    Beispiel für die Berechnung:
+    if ((x & 8000h) == 8000h) // y negativ
+    y = - [dez(High_Byte(!x)) 16 + dez(High_Nibble (Low_Byte (!x)))
+    + (dez(Low_Nibble (Low_Byte (!x))) +1 ) / 16]
+    else                       // y positiv
+    y = dez(High_Byte(x)) 16 + dez(High_ Nibble (Low Byte (x)))
+    + dez(Low_ Nibble (Low Byte (x))) / 16
+    """
+    def value(self,data):
+        highByte = ord(data[self.offset+1])
+        lowByte= ord(data[self.offset])
+        if (0x8000 & (highByte<<8 | lowByte)) == 0x8000:
+            return (-1) * ( (0xff^highByte)*16 + (0xff^(lowByte>>4)) + (0x0ff^(0xf&lowByte) + 1)/16.0 )
+        else:
+            return highByte*16 + (lowByte>>4) + (lowByte&0xf)/16.0
+
+class Data2b(DataField):
+    """
+    if ((x&8000h) == 8000h) // y negativ
+    y = - [dez(High_Byte(!x)) + (dez(Low_Byte(!x)) + 1) / 256]
+    else                        // y positiv
+    y = dez(High_Byte (x)) + dez(Low_Byte (x)) / 256
+    """
+    def value(self,data):
+        highByte = ord(data[self.offset+1])
+        lowByte= ord(data[self.offset])
+        if (0x8000 & (highByte<<8 | lowByte)) == 0x8000:
+            return (-1) * ((0xff^highByte) + (0xff^lowByte+1)/256.0)
+        else:
+            return highByte + lowByte/256.0
+        
+class Bit(DataField):
+    def value(self, data):
+        return ord(data[self.offset]) == 0x1
+    
+class Word(DataField):
+    def value(self, data):
+        lb, hb = data[self.offset], data[self.offset+1]
+        return ord(lb) + (ord(hb)<<8)
+    
+class Bcd(DataField):
+    """
+    y = dez(High_Nibble(x))*10 + dez(Low_Nibble(x))
+    """
+    def value(self, data):
+        byte = ord(data[self.offset])
+        return (byte >> 4) * 10 + (byte & 0xf)
+    
+class Byte(DataField):
+    def value(self, data):
+        return ord(data[self.offset])
+    
+
+class ByteEnum(DataField):
+    def __init__(self, name, offset, values):
+        fields.DataField.__init__(self, name, offset)
+        self.values = values
+
+    def value(self, data):
+        value = ord(data[self.offset])
+        if self.values.has_key(value):
+            return self.values[value]
+        else:
+            return None