diff --git a/ADS1X15.cpp b/ADS1X15.cpp
index 4960cab..f764958 100644
--- a/ADS1X15.cpp
+++ b/ADS1X15.cpp
@@ -1,7 +1,7 @@
 //
 //    FILE: ADS1X15.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.3.3
+// VERSION: 0.3.4
 //    DATE: 2013-03-24
 // PUPROSE: Arduino library for ADS1015 and ADS1115
 //     URL: https://github.com/RobTillaart/ADS1X15
@@ -22,6 +22,8 @@
 //  0.3.1   2021-04-25  #22, add get/setClock() for Wire speed + reset()
 //  0.3.2   2021-10-07  fix build-CI; update readme + add new examples
 //  0.3.3   2021-10-17  update build-CI (esp32), readme.md, keywords.txt
+//  0.3.4   2021-12-11  update library.json, license, minor edits incl layout)
+//                      add unit test constants.
 
 
 #include "ADS1X15.h"
@@ -102,7 +104,7 @@ differs for different devices, check datasheet or readme.md
 #define ADS1X15_COMP_QUE_1_CONV         0x0000  // trigger alert after 1 convert
 #define ADS1X15_COMP_QUE_2_CONV         0x0001  // trigger alert after 2 converts
 #define ADS1X15_COMP_QUE_4_CONV         0x0002  // trigger alert after 4 converts
-#define ADS1X15_COMP_QUE_NONE           0x0003  // dosable comparator
+#define ADS1X15_COMP_QUE_NONE           0x0003  // disable comparator
 
 
 // _CONFIG masks
@@ -230,21 +232,21 @@ uint8_t ADS1X15::getGain()
 }
 
 
-float ADS1X15::toVoltage(int16_t val)
+float ADS1X15::toVoltage(int16_t value)
 {
-  if (val == 0) return 0;
+  if (value == 0) return 0;
 
   float volts = getMaxVoltage();
   if (volts < 0) return volts;
 
-  volts *= val;
+  volts *= value;
   if (_config & ADS_CONF_RES_16)
   {
-    volts /= 32767;  // val = 16 bits - sign bit = 15 bits mantissa
+    volts /= 32767;  // value = 16 bits - sign bit = 15 bits mantissa
   }
   else
   {
-    volts /= 2047;   // val = 12 bits - sign bit = 11 bit mantissa
+    volts /= 2047;   // value = 12 bits - sign bit = 11 bit mantissa
   }
   return volts;
 }
@@ -418,6 +420,7 @@ int16_t ADS1X15::_readADC(uint16_t readmode)
   return getValue();
 }
 
+
 void ADS1X15::_requestADC(uint16_t readmode)
 {
   // write to register is needed in continuous mode as other flags can be changed
@@ -436,6 +439,7 @@ void ADS1X15::_requestADC(uint16_t readmode)
   _writeRegister(_address, ADS1X15_REG_CONFIG, config);
 }
 
+
 bool ADS1X15::_writeRegister(uint8_t address, uint8_t reg, uint16_t value)
 {
   _wire->beginTransmission(address);
@@ -445,6 +449,7 @@ bool ADS1X15::_writeRegister(uint8_t address, uint8_t reg, uint16_t value)
   return (_wire->endTransmission() == 0);
 }
 
+
 uint16_t ADS1X15::_readRegister(uint8_t address, uint8_t reg)
 {
   _wire->beginTransmission(address);
@@ -506,43 +511,49 @@ ADS1015::ADS1015(uint8_t address, TwoWire *wire)
   _maxPorts = 4;
 }
 
+
 int16_t ADS1015::readADC_Differential_0_3()
 {
   return _readADC(ADS1X15_MUX_DIFF_0_3);
 }
 
+
 int16_t ADS1015::readADC_Differential_1_3()
 {
   return _readADC(ADS1X15_MUX_DIFF_1_3);
 }
 
+
 int16_t ADS1015::readADC_Differential_2_3()
 {
   return _readADC(ADS1X15_MUX_DIFF_2_3);
 }
 
+
 int16_t ADS1015::readADC_Differential_0_2()
 {
   return readADC(2) - readADC(0);
 }
 
+
 int16_t ADS1015::readADC_Differential_1_2()
 {
   return readADC(2) - readADC(1);;
 }
 
 
-
 void ADS1015::requestADC_Differential_0_3()
 {
   _requestADC(ADS1X15_MUX_DIFF_0_3);
 }
 
+
 void ADS1015::requestADC_Differential_1_3()
 {
   _requestADC(ADS1X15_MUX_DIFF_1_3);
 }
 
+
 void ADS1015::requestADC_Differential_2_3()
 {
   _requestADC(ADS1X15_MUX_DIFF_2_3);
@@ -593,44 +604,54 @@ ADS1115::ADS1115(uint8_t address, TwoWire *wire)
   _maxPorts = 4;
 }
 
+
 int16_t ADS1115::readADC_Differential_0_3()
 {
   return _readADC(ADS1X15_MUX_DIFF_0_3);
 }
 
+
 int16_t ADS1115::readADC_Differential_1_3()
 {
   return _readADC(ADS1X15_MUX_DIFF_1_3);
 }
 
+
 int16_t ADS1115::readADC_Differential_2_3()
 {
   return _readADC(ADS1X15_MUX_DIFF_2_3);
 }
 
+
 int16_t ADS1115::readADC_Differential_0_2()
 {
   return readADC(2) - readADC(0);
 }
 
+
 int16_t ADS1115::readADC_Differential_1_2()
 {
   return readADC(2) - readADC(1);;
 }
 
+
 void ADS1115::requestADC_Differential_0_3()
 {
   _requestADC(ADS1X15_MUX_DIFF_0_3);
 }
 
+
 void ADS1115::requestADC_Differential_1_3()
 {
   _requestADC(ADS1X15_MUX_DIFF_1_3);
 }
 
+
 void ADS1115::requestADC_Differential_2_3()
 {
   _requestADC(ADS1X15_MUX_DIFF_2_3);
 }
 
+
 // --- END OF FILE
+
diff --git a/ADS1X15.h b/ADS1X15.h
index 2ec9dd7..966e227 100644
--- a/ADS1X15.h
+++ b/ADS1X15.h
@@ -2,7 +2,7 @@
 //
 //    FILE: ADS1X15.H
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.3.3
+// VERSION: 0.3.4
 //    DATE: 2013-03-24
 // PUPROSE: Arduino library for ADS1015 and ADS1115
 //     URL: https://github.com/RobTillaart/ADS1X15
@@ -12,7 +12,7 @@
 #include "Arduino.h"
 #include "Wire.h"
 
-#define ADS1X15_LIB_VERSION               (F("0.3.3"))
+#define ADS1X15_LIB_VERSION               (F("0.3.4"))
 
 // allow compile time default address
 // address in { 0x48, 0x49, 0x4A, 0x4B }, no test...
@@ -53,7 +53,7 @@ class ADS1X15
   uint8_t  getGain();                    // 0xFF == invalid gain error.
 
   // both may return ADS1X15_INVALID_VOLTAGE if the gain is invalid.
-  float    toVoltage(int16_t val = 1);   //  converts raw to voltage
+  float    toVoltage(int16_t value = 1); //  converts raw to voltage
   float    getMaxVoltage();              //  -100 == invalid voltage error
 
   // 0  =  CONTINUOUS
diff --git a/LICENSE b/LICENSE
index 39d07e3..c9bd779 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2013-2021 Rob Tillaart
+Copyright (c) 2013-2022 Rob Tillaart
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/README.md b/README.md
index 441b626..0c364fa 100644
--- a/README.md
+++ b/README.md
@@ -7,7 +7,7 @@
 
 # ADS1X15
 
-Arduino library for I2C ADC ADS1015, ADS1115,
+Arduino library for I2C ADC ADS1015, ADS1115, and similar.
 
 
 ## Description
@@ -31,7 +31,7 @@ differential measurement.
 
 ## Interface
 
-The address of the ADS1113/4/5 is determined by to which pin the ADDR
+The address of the ADS1113/4/5 is determined by to which pin the **ADDR**
 is connected to:
 
 | ADDR pin connected to | Address | Notes   |
@@ -42,7 +42,7 @@ is connected to:
 |      SCL              |   0x4B  |         |
 
 
-- **ADS1x15()** constructor, should not be used.
+- **ADS1x15()** base constructor, should not be used.
 - **ADS1013(address, TwoWire \*wire = &Wire)** Constructor with device address, 
 and optional the Wire interface as parameter.
 - **ADS1014(address, TwoWire \*wire = &Wire)** Constructor with device address, 
@@ -170,7 +170,7 @@ in terms of code
   {
     if (ADS.isReady())
     {
-      val = ADS.getValue();
+      value = ADS.getValue();
       ADS.requestADC(pin);       // request new conversion
     }
     // do other things here
@@ -183,6 +183,7 @@ See examples
 ## ReadADC Differential
 
 For reading the ADC in a differential way there are 4 calls possible.
+
 - **int16_t readADC_Differential_0_1()** returns the difference between 2 ADC pins.
 - **int16_t readADC_Differential_0_3()** ADS1x15 only
 - **int16_t readADC_Differential_1_3()** ADS1x15 only
@@ -191,6 +192,7 @@ For reading the ADC in a differential way there are 4 calls possible.
 - **int16_t readADC_Differential_1_2()** ADS1x15 only - in software (no async equivalent)
 
 The differential reading of the ADC can also be done with asynchronous calls.
+
 - **void requestADC_Differential_0_1()** starts conversion for differential reading
 - **void requestADC_Differential_0_3()** ADS1x15 only
 - **void requestADC_Differential_1_3()** ADS1x15 only
@@ -199,8 +201,8 @@ The differential reading of the ADC can also be done with asynchronous calls.
 After one of these calls one need to call
 - **int16_t getValue()** Read the result of the last conversion.
 
-The readiness of a CONTINUOUS conversion can only be detected by the RDY line.
-Use interrupt for this, see examples.
+The readiness of a CONTINUOUS conversion can only be detected by the **RDY** line.
+Best to use an interrupt for this, see examples.
 
 
 #### ReadADC continuous mode
@@ -226,6 +228,7 @@ See examples.
 
 If the thresholdHigh is set to 0x0100 and the thresholdLow to 0x0000
 the **ALERT/RDY** pin is triggered when a conversion is ready.
+
 - **void setComparatorThresholdLow(int16_t lo)** writes value to device directly.
 - **void setComparatorThresholdHigh(int16_t hi)** writes value to device directly.
 - **int16_t getComparatorThresholdLow()** reads value from device.
@@ -304,6 +307,7 @@ A value of 3 (or above) effectively disables the comparator. See table below.
 
 Depending on the comparator mode **TRADITIONAL** or **WINDOW** the thresholds registers
 mean something different see - Comparator Mode above or datasheet.
+
 - **void setComparatorThresholdLow(int16_t lo)** set the low threshold; take care the hi >= lo.
 - **void setComparatorThresholdHigh(int16_t hi)**  set the high threshold; take care the hi >= lo.
 - **int16_t getComparatorThresholdLow()** reads value from device.
diff --git a/examples/ADS_async_16_channel/ADS_async_16_channel.ino b/examples/ADS_async_16_channel/ADS_async_16_channel.ino
index 4fcc8bb..f2897fe 100644
--- a/examples/ADS_async_16_channel/ADS_async_16_channel.ino
+++ b/examples/ADS_async_16_channel/ADS_async_16_channel.ino
@@ -22,6 +22,7 @@ int idx = 0;
 
 uint32_t last = 0, now = 0;
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -116,4 +117,6 @@ void ADS_print_all()
   Serial.println();
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_async_8_channel/ADS_async_8_channel.ino b/examples/ADS_async_8_channel/ADS_async_8_channel.ino
index 3e0ad54..f493672 100644
--- a/examples/ADS_async_8_channel/ADS_async_8_channel.ino
+++ b/examples/ADS_async_8_channel/ADS_async_8_channel.ino
@@ -28,6 +28,7 @@ int     idx = 0;
 
 uint32_t lastTime = 0;
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -133,4 +134,6 @@ void ADS_print_all()
   //  Serial.println();
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_async_differential/ADS_async_differential.ino b/examples/ADS_async_differential/ADS_async_differential.ino
index 36103c9..edbe73b 100644
--- a/examples/ADS_async_differential/ADS_async_differential.ino
+++ b/examples/ADS_async_differential/ADS_async_differential.ino
@@ -18,6 +18,7 @@
 
 #include "ADS1X15.h"
 
+
 // choose you sensor
 // ADS1013 ADS(0x48);
 // ADS1014 ADS(0x48);
@@ -51,6 +52,7 @@ void setup()
   ADS.requestADC_Differential_0_1();
 }
 
+
 void loop()
 {
   if (handleConversion() == true)
@@ -92,4 +94,6 @@ bool handleConversion()
   return false;  // default not all read
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_continuous/ADS_continuous.ino b/examples/ADS_continuous/ADS_continuous.ino
index 2e0c343..3c6a7e0 100644
--- a/examples/ADS_continuous/ADS_continuous.ino
+++ b/examples/ADS_continuous/ADS_continuous.ino
@@ -16,6 +16,7 @@
 
 #include "ADS1X15.h"
 
+
 // choose you sensor
 // ADS1013 ADS(0x48);
 // ADS1014 ADS(0x48);
@@ -39,9 +40,13 @@ void setup()
   ADS.readADC(0);      // first read to trigger
 }
 
+
 void loop()
 {
   Serial.println(ADS.getValue());
+  // optional other code here
 }
 
-// -- END OF FILE --
\ No newline at end of file
+
+// -- END OF FILE --
+
diff --git a/examples/ADS_continuous_4_channel/ADS_continuous_4_channel.ino b/examples/ADS_continuous_4_channel/ADS_continuous_4_channel.ino
index 22666be..1e83f8b 100644
--- a/examples/ADS_continuous_4_channel/ADS_continuous_4_channel.ino
+++ b/examples/ADS_continuous_4_channel/ADS_continuous_4_channel.ino
@@ -18,8 +18,10 @@
 // so one can see these as references in the output.
 //
 
+
 #include "ADS1X15.h"
 
+
 // choose you sensor
 // ADS1013 ADS(0x48);
 // ADS1014 ADS(0x48);
@@ -32,6 +34,7 @@ volatile bool RDY = false;
 uint8_t channel = 0;
 int16_t val[4] = { 0, 0, 0, 0 };
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -59,6 +62,7 @@ void setup()
   ADS.readADC(channel);     // trigger first read
 }
 
+
 void loop()
 {
   handleConversion();
@@ -73,11 +77,15 @@ void loop()
   delay(100);
 }
 
+
+//  interrupt service routine
+//  kept as minimal as possible 
 void adsReady()
 {
   RDY = true;
 }
 
+
 void handleConversion()
 {
   if (RDY)
@@ -91,4 +99,7 @@ void handleConversion()
     RDY = false;
   }
 }
+
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_continuous_8_channel/ADS_continuous_8_channel.ino b/examples/ADS_continuous_8_channel/ADS_continuous_8_channel.ino
index cee55b0..f586c17 100644
--- a/examples/ADS_continuous_8_channel/ADS_continuous_8_channel.ino
+++ b/examples/ADS_continuous_8_channel/ADS_continuous_8_channel.ino
@@ -18,18 +18,25 @@
 // so one can see these as references in the output.
 //
 
+
 #include "ADS1X15.h"
 
+
 // adjust addresses if needed
 ADS1115 ADS_1(0x49);
 ADS1115 ADS_2(0x48);
 
+//  two interrupt flags
 volatile bool RDY_1 = false;
 volatile bool RDY_2 = false;
-uint8_t channel_1 = 0;
-uint8_t channel_2 = 0;
+
+uint8_t channel_1 = 0;         // channel from device 1
+uint8_t channel_2 = 0;         // channel from device 2
+
+//  array to hold the data.
 int16_t val[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -73,6 +80,7 @@ void setup()
   ADS_2.readADC(channel_2);  // trigger first read
 }
 
+
 void loop()
 {
   handleConversion();
@@ -87,17 +95,20 @@ void loop()
   delay(100);
 }
 
-// catch interrupt and set flag
+
+// catch interrupt and set flag device 1
 void adsReady_1()
 {
   RDY_1 = true;
 }
 
+// catch interrupt and set flag device 1
 void adsReady_2()
 {
   RDY_2 = true;
 }
 
+
 // handle conversions that are ready
 void handleConversion()
 {
@@ -123,4 +134,6 @@ void handleConversion()
   }
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_continuous_differential/ADS_continuous_differential.ino b/examples/ADS_continuous_differential/ADS_continuous_differential.ino
index 7a83336..d689fc6 100644
--- a/examples/ADS_continuous_differential/ADS_continuous_differential.ino
+++ b/examples/ADS_continuous_differential/ADS_continuous_differential.ino
@@ -18,12 +18,14 @@
 
 #include "ADS1X15.h"
 
+
 // choose you sensor
 // ADS1013 ADS(0x48);
 // ADS1014 ADS(0x48);
 // ADS1015 ADS(0x48);
 // ADS1113 ADS(0x48);
 // ADS1114 ADS(0x48);
+
 ADS1115 ADS(0x48);
 
 
@@ -87,12 +89,14 @@ void loop()
   // delay(10);
 }
 
-// interrupt handler, just sets the RDY flag
+
+// interrupt handler, sets the RDY flag
 void adsReady()
 {
   RDY = true;
 }
 
+
 // can be changed to hold other differentials or normal reads too.
 bool handleConversion()
 {
@@ -121,3 +125,4 @@ bool handleConversion()
 
 
 // -- END OF FILE --
+
diff --git a/examples/ADS_differential/ADS_differential.ino b/examples/ADS_differential/ADS_differential.ino
index 91711a8..c1a05cb 100644
--- a/examples/ADS_differential/ADS_differential.ino
+++ b/examples/ADS_differential/ADS_differential.ino
@@ -26,10 +26,12 @@
 // measure at x and y  (connect to AIN0 and AIN1).
 // range from -VDD .. +VDD are possible
 
+
 #include <ADS1X15.h>
 
 ADS1115 ADS(0x48);
 
+
 void setup() 
 {
   Serial.begin(115200);
@@ -41,6 +43,7 @@ void setup()
   ADS.setGain(0);
 }
 
+
 void loop() 
 {
   int16_t val_01 = ADS.readADC_Differential_0_1();  
@@ -61,4 +64,6 @@ void loop()
   delay(1000);
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_high_speed_differential/ADS_high_speed_differential.ino b/examples/ADS_high_speed_differential/ADS_high_speed_differential.ino
index d548029..252a95c 100644
--- a/examples/ADS_high_speed_differential/ADS_high_speed_differential.ino
+++ b/examples/ADS_high_speed_differential/ADS_high_speed_differential.ino
@@ -71,6 +71,7 @@ void setup()
   ADS_2.readADC(channel);    // trigger first read
 }
 
+
 void loop()
 {
   if (handleConversion() == true)
@@ -82,8 +83,6 @@ void loop()
     }
     Serial.println();
   }
-
-
 }
 
 
@@ -122,3 +121,4 @@ bool handleConversion()
 
 
 // -- END OF FILE --
+
diff --git a/examples/ADS_minimum/ADS_minimum.ino b/examples/ADS_minimum/ADS_minimum.ino
index d854951..7e948d1 100644
--- a/examples/ADS_minimum/ADS_minimum.ino
+++ b/examples/ADS_minimum/ADS_minimum.ino
@@ -15,16 +15,20 @@
 
 // view with Serial Plotter
 
+
 #include "ADS1X15.h"
 
+
 // choose you sensor
 // ADS1013 ADS(0x48);
 // ADS1014 ADS(0x48);
 // ADS1015 ADS(0x48);
 // ADS1113 ADS(0x48);
 // ADS1114 ADS(0x48);
+
 ADS1115 ADS(0x48);
 
+
 void setup() 
 {
   Serial.begin(115200);
@@ -37,10 +41,13 @@ void setup()
   Serial.println("Voltage");
 }
 
+
 void loop() 
 {
   int16_t raw = ADS.readADC(0);
   Serial.println(ADS.toVoltage(raw), 3);
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_performance/ADS_performance.ino b/examples/ADS_performance/ADS_performance.ino
index a94d8b8..c1ef141 100644
--- a/examples/ADS_performance/ADS_performance.ino
+++ b/examples/ADS_performance/ADS_performance.ino
@@ -16,17 +16,20 @@
 
 #include "ADS1X15.h"
 
+
 // choose you sensor
 // ADS1013 ADS(0x48);
 // ADS1014 ADS(0x48);
 // ADS1015 ADS(0x48);
 // ADS1113 ADS(0x48);
 // ADS1114 ADS(0x48);
+
 ADS1115 ADS(0x48);
 
 uint32_t start, d1, d2;
 int x;
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -53,10 +56,12 @@ void setup()
   Serial.println("\nDone...");
 }
 
+
 void loop()
 {
 }
 
+
 void test_single_shot()
 {
   Serial.print(__FUNCTION__);
@@ -73,6 +78,7 @@ void test_single_shot()
   Serial.println(d1);
 }
 
+
 void test_continuous()
 {
   Serial.print(__FUNCTION__);
@@ -89,4 +95,6 @@ void test_continuous()
   Serial.println(d2);
 }
 
-// -- END OF FILE --
\ No newline at end of file
+
+// -- END OF FILE --
+
diff --git a/examples/ADS_read/ADS_read.ino b/examples/ADS_read/ADS_read.ino
index dba2f67..49a8aae 100644
--- a/examples/ADS_read/ADS_read.ino
+++ b/examples/ADS_read/ADS_read.ino
@@ -14,10 +14,12 @@
 // measure at x (connect to AIN0).
 //
 
+
 #include "ADS1X15.h"
 
 ADS1115 ADS(0x48);
 
+
 void setup() 
 {
   Serial.begin(115200);
@@ -28,6 +30,7 @@ void setup()
   ADS.begin();
 }
 
+
 void loop() 
 {
   ADS.setGain(0);
@@ -48,4 +51,6 @@ void loop()
   delay(1000);
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_read_RDY/ADS_read_RDY.ino b/examples/ADS_read_RDY/ADS_read_RDY.ino
index fa84eb6..7daf00b 100644
--- a/examples/ADS_read_RDY/ADS_read_RDY.ino
+++ b/examples/ADS_read_RDY/ADS_read_RDY.ino
@@ -19,10 +19,12 @@
 // The RDY pin (or ALERT Pin) is triggered when conversion is ready
 //
 
+
 #include "ADS1X15.h"
 
 ADS1115 ADS(0x48);
 
+
 void setup() 
 {
   Serial.begin(115200);
@@ -43,6 +45,7 @@ void setup()
   ADS.setComparatorLatch(0);
 }
 
+
 void loop() 
 {
   ADS.setGain(0);
@@ -59,4 +62,6 @@ void loop()
   delay(1000);
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_read_async/ADS_read_async.ino b/examples/ADS_read_async/ADS_read_async.ino
index 174f919..abb8445 100644
--- a/examples/ADS_read_async/ADS_read_async.ino
+++ b/examples/ADS_read_async/ADS_read_async.ino
@@ -14,11 +14,13 @@
 // measure at x (connect to AIN0).
 //
 
+
 #include "ADS1X15.h"
 
 ADS1115 ADS(0x48);
 float f = 0;
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -32,6 +34,7 @@ void setup()
   ADS.requestADC(0);
 }
 
+
 void loop()
 {
   if (ADS.isBusy() == false)
@@ -47,4 +50,6 @@ void loop()
   delay(2000);
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_read_async_rdy/ADS_read_async_rdy.ino b/examples/ADS_read_async_rdy/ADS_read_async_rdy.ino
index 9b04081..847a1f1 100644
--- a/examples/ADS_read_async_rdy/ADS_read_async_rdy.ino
+++ b/examples/ADS_read_async_rdy/ADS_read_async_rdy.ino
@@ -19,11 +19,13 @@
 // The RDY pin (or ALERT Pin) is triggered when conversion is ready
 //
 
+
 #include "ADS1X15.h"
 
 ADS1115 ADS(0x48);
 float f = 0;
 
+
 void setup() 
 {
   Serial.begin(115200);
@@ -44,6 +46,7 @@ void setup()
   ADS.setComparatorLatch(0);
 }
 
+
 void loop() 
 {
   if (ADS.isReady())
@@ -59,4 +62,6 @@ void loop()
   delay(2000);
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_read_comparator_1/ADS_read_comparator_1.ino b/examples/ADS_read_comparator_1/ADS_read_comparator_1.ino
index e7315c1..d188bbb 100644
--- a/examples/ADS_read_comparator_1/ADS_read_comparator_1.ino
+++ b/examples/ADS_read_comparator_1/ADS_read_comparator_1.ino
@@ -25,6 +25,7 @@
 
 ADS1115 ADS(0x48);
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -55,9 +56,9 @@ void setup()
   
   Serial.println(ADS.getComparatorThresholdLow());
   Serial.println(ADS.getComparatorThresholdHigh());
-
 }
 
+
 void loop()
 {
   ADS.setGain(0);
@@ -79,4 +80,6 @@ void loop()
   delay(100);
 }
 
+
 // -- END OF FILE --
+
diff --git a/examples/ADS_setWireClock/ADS_setWireClock.ino b/examples/ADS_setWireClock/ADS_setWireClock.ino
index d2f0232..558a44a 100644
--- a/examples/ADS_setWireClock/ADS_setWireClock.ino
+++ b/examples/ADS_setWireClock/ADS_setWireClock.ino
@@ -14,10 +14,12 @@
 // measure at x (connect to AIN0).
 //
 
+
 #include "ADS1X15.h"
 
 ADS1115 ADS(0x48);
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -39,6 +41,7 @@ void setup()
   Serial.println();
 }
 
+
 void loop()
 {
   ADS.setGain(0);
@@ -59,4 +62,6 @@ void loop()
   delay(1000);
 }
 
+
 // -- END OF FILE --
+
diff --git a/keywords.txt b/keywords.txt
index f9f6801..414a842 100644
--- a/keywords.txt
+++ b/keywords.txt
@@ -1,6 +1,6 @@
-# Syntax Coloring Map For ADS1X15
+# Syntax Colouring Map For ADS1X15
 
-# Datatypes (KEYWORD1)
+# Data types (KEYWORD1)
 ADS1X13	KEYWORD1
 ADS1014	KEYWORD1
 ADS1015	KEYWORD1
@@ -61,6 +61,7 @@ requestADC_Differential_2_3	KEYWORD2
 
 # Constants (LITERAL1)
 ADS1X15_LIB_VERSION	LITERAL1
+
 ADS1X15_INVALID_VOLTAGE	LITERAL1
 ADS1X15_INVALID_GAIN	LITERAL1
 ADS1X15_INVALID_MODE	LITERAL1
diff --git a/library.json b/library.json
index 283be3a..8e881d5 100644
--- a/library.json
+++ b/library.json
@@ -15,9 +15,9 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/ADS1X15"
   },
-  "version": "0.3.3",
+  "version": "0.3.4",
   "license": "MIT",
   "frameworks": "*",
   "platforms": "*",
-  "headers": "AD1x15.h"
+  "headers": "ADS1X15.h"
 }
diff --git a/library.properties b/library.properties
index 7d44a46..6c8bf29 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=ADS1X15
-version=0.3.3
+version=0.3.4
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino library for ADS1015 - I2C 12 bit ADC and ADS1115 I2C 16 bit ADC
diff --git a/test/unit_test_001.cpp b/test/unit_test_001.cpp
index 0489204..5f0a395 100644
--- a/test/unit_test_001.cpp
+++ b/test/unit_test_001.cpp
@@ -29,10 +29,25 @@ unittest_setup()
 {
 }
 
+
 unittest_teardown()
 {
 }
 
+
+unittest(test_constants)
+{
+  fprintf(stderr, "ADS1X15_LIB_VERSION: %s\n", (char *) ADS1X15_LIB_VERSION);
+
+  assertEqual(0x48, ADS1015_ADDRESS);
+  assertEqual(0x48, ADS1115_ADDRESS);
+  assertEqual(   0, ADS1X15_OK);
+  assertEqual(-100, ADS1X15_INVALID_VOLTAGE);
+  assertEqual(0xFF, ADS1X15_INVALID_GAIN);
+  assertEqual(0xFE, ADS1X15_INVALID_MODE);
+}
+
+
 unittest(test_begin)
 {
   ADS1115 ADS(0x48);
@@ -41,6 +56,7 @@ unittest(test_begin)
   assertTrue(ADS.isBusy());
 }
 
+
 unittest(test_gain)
 {
   ADS1115 ADS(0x48);
@@ -58,6 +74,7 @@ unittest(test_gain)
   assertEqual(0, ADS.getGain());
 }
 
+
 unittest(test_Voltage)
 {
   ADS1115 ADS(0x48);
@@ -78,4 +95,5 @@ unittest(test_Voltage)
 
 unittest_main()
 
+
 // --------