diff --git a/libraries/AD524X/AD524X.cpp b/libraries/AD524X/AD524X.cpp
index fca377d7..16587081 100644
--- a/libraries/AD524X/AD524X.cpp
+++ b/libraries/AD524X/AD524X.cpp
@@ -18,7 +18,7 @@
 #define AS524X_O1_HIGH  0x10
 #define AS524X_O2_HIGH  0x08
 
-AD524X::AD524X(uint8_t address)
+AD524X::AD524X(const uint8_t address)
 {
     // address: 0x01011xx = 0x2C - 0x2F
     _address = address;
@@ -32,7 +32,7 @@ uint8_t AD524X::zeroAll()
     return write(1, 0);
 }
 
-uint8_t AD524X::write(uint8_t rdac, uint8_t value)
+uint8_t AD524X::write(const uint8_t rdac, const uint8_t value)
 {
     if (rdac > 1) return AS524X_ERROR;
 
@@ -43,7 +43,7 @@ uint8_t AD524X::write(uint8_t rdac, uint8_t value)
     return send(cmd, value);
 }
 
-uint8_t AD524X::write(uint8_t rdac, uint8_t value, uint8_t O1, uint8_t O2)
+uint8_t AD524X::write(const uint8_t rdac, const uint8_t value, const uint8_t O1, const uint8_t O2)
 {
     if (rdac > 1) return AS524X_ERROR;
 
@@ -56,16 +56,16 @@ uint8_t AD524X::write(uint8_t rdac, uint8_t value, uint8_t O1, uint8_t O2)
     return send(cmd, value);
 }
 
-uint8_t AD524X::setO1(uint8_t v)
+uint8_t AD524X::setO1(const uint8_t value)
 {
-    _O1 = (v == LOW) ? 0 : AS524X_O1_HIGH;
+    _O1 = (value == LOW) ? 0 : AS524X_O1_HIGH;
     uint8_t cmd = AS524X_RDAC0 | _O1 | _O2;
     return send(cmd, _lastValue[0]);
 }
 
-uint8_t AD524X::setO2(uint8_t v)
+uint8_t AD524X::setO2(const uint8_t value)
 {
-    _O2 = (v == LOW) ? 0: AS524X_O2_HIGH;
+    _O2 = (value == LOW) ? 0: AS524X_O2_HIGH;
     uint8_t cmd = AS524X_RDAC0 | _O1 | _O2;
     return send(cmd, _lastValue[0]);
 }
@@ -80,12 +80,12 @@ uint8_t AD524X::getO2()
     return (_O2 > 0);
 }
 
-uint8_t AD524X::read(uint8_t rdac)
+uint8_t AD524X::read(const uint8_t rdac)
 {
     return _lastValue[rdac];
 }
 
-uint8_t AD524X::midScaleReset(uint8_t rdac)
+uint8_t AD524X::midScaleReset(const uint8_t rdac)
 {
     if (rdac > 1) return AS524X_ERROR;
 
@@ -107,7 +107,7 @@ uint8_t AD524X::midScaleReset(uint8_t rdac)
 //
 // PRIVATE
 //
-uint8_t AD524X::send(uint8_t cmd, uint8_t value)
+uint8_t AD524X::send(const uint8_t cmd, const uint8_t value)
 {
     Wire.beginTransmission(_address);
     Wire.write(cmd);
diff --git a/libraries/AD524X/AD524X.h b/libraries/AD524X/AD524X.h
index 996ca5f8..8af57997 100644
--- a/libraries/AD524X/AD524X.h
+++ b/libraries/AD524X/AD524X.h
@@ -1,7 +1,7 @@
 //
 //    FILE: AD524X.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.1.01
+// VERSION: 0.1.02
 // PURPOSE: I2C digital PotentioMeter AD5241 AD5242
 //    DATE: 2013-10-12
 //     URL:
@@ -20,7 +20,7 @@
 
 #include <Wire.h>
 
-#define AD524X_VERSION "0.1.01"
+#define AD524X_VERSION "0.1.02"
 
 #define AS524X_OK       0
 #define AS524X_ERROR    -10
@@ -29,28 +29,28 @@ class AD524X
 {
 public:
     // address
-    AD524X(uint8_t);
+    AD524X(const uint8_t);
     
     uint8_t zeroAll();
     // rdac
-    uint8_t read(uint8_t);
+    uint8_t read(const uint8_t);
     // rdac value
-    uint8_t write(uint8_t, uint8_t);
+    uint8_t write(const uint8_t, const uint8_t);
     // rdac value O1 O2
-    uint8_t write(uint8_t, uint8_t, uint8_t, uint8_t);
+    uint8_t write(const uint8_t, const uint8_t, const uint8_t, const uint8_t);
     
-    uint8_t setO1(uint8_t);  // HIGH / LOW
-    uint8_t setO2(uint8_t);  // HIGH / LOW
+    uint8_t setO1(const uint8_t);  // HIGH / LOW
+    uint8_t setO2(const uint8_t);  // HIGH / LOW
     uint8_t getO1();
     uint8_t getO2();
     
     // rdac
-    uint8_t midScaleReset(uint8_t);
+    uint8_t midScaleReset(const uint8_t);
     //
     // uint8_t shutDown();
 
 private:
-    uint8_t send(uint8_t, uint8_t);     // cmd value
+    uint8_t send(const uint8_t, const uint8_t);     // cmd value
 
     uint8_t _address;
     uint8_t _lastValue[2];