diff --git a/CHANGELOG.md b/CHANGELOG.md
index 123f9f7..28cb959 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,11 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
+## [0.3.1] - 2024-01-26
+- update readme.md
+- update examples
+
+
 ## [0.3.0] - 2023-10-25
 - simplify begin()
 - updated all examples
diff --git a/DHT20.cpp b/DHT20.cpp
index e953918..101f82b 100644
--- a/DHT20.cpp
+++ b/DHT20.cpp
@@ -1,7 +1,7 @@
 //
 //    FILE: DHT20.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.3.0
+// VERSION: 0.3.1
 // PURPOSE: Arduino library for DHT20 I2C temperature and humidity sensor.
 
 
diff --git a/DHT20.h b/DHT20.h
index baa5f7f..cbdd840 100644
--- a/DHT20.h
+++ b/DHT20.h
@@ -3,7 +3,7 @@
 //    FILE: DHT20.h
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Arduino library for DHT20 I2C temperature and humidity sensor.
-// VERSION: 0.3.0
+// VERSION: 0.3.1
 //     URL: https://github.com/RobTillaart/DHT20
 //
 
@@ -20,7 +20,7 @@
 #include "Arduino.h"
 #include "Wire.h"
 
-#define DHT20_LIB_VERSION                    (F("0.3.0"))
+#define DHT20_LIB_VERSION                    (F("0.3.1"))
 
 #define DHT20_OK                             0
 #define DHT20_ERROR_CHECKSUM                -10
diff --git a/LICENSE b/LICENSE
index 7ff5257..3f2859b 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2022-2023 Rob Tillaart
+Copyright (c) 2022-2024 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 a3516f7..5d556e0 100644
--- a/README.md
+++ b/README.md
@@ -21,8 +21,7 @@ The DHT20 is a humidity and temperature sensor.
 The sensor has a fixed address of **0x38**.
 It is not known if the address can be changed.
 
-The library must be initiated by calling the **begin()** function, 
-or **begin(dataPin, clockPin)** for **ESP32** and similar platforms.
+The library must be initiated by calling the **begin()** function.
 
 Thereafter one has to call the **read()** function to do the actual reading,
 and call **getTemperature()** and **getHumidity()** to get the measured values.
@@ -55,10 +54,14 @@ reset the sensor if needed in both synchronous and asynchronous calls.
 This keeps the API simple. The reads are 1-2 ms slower than 0.1.4. (< 50 ms).
 Still far below the 80 ms mentioned in the datasheet. 
 
-### 0.3.0
 
-User should call Wire.begin(), and setting I2C pins himself.
-It is removed from the specific ESP32 begin() call to be more generic.
+#### 0.3.0 Breaking change
+
+Version 0.3.0 introduced a breaking change.
+You cannot set the pins in **begin()** any more.
+This reduces the dependency of processor dependent Wire implementations.
+The user has to call **Wire.begin()** and can optionally set the Wire pins
+before calling **begin()**.
 
 
 #### Tested
@@ -75,6 +78,24 @@ The sensor has a fixed address of **0x38**.
 It is not known if the address can be changed.
 
 
+#### I2C multiplexing
+
+Sometimes you need to control more devices than possible with the default
+address range the device provides.
+This is possible with an I2C multiplexer e.g. TCA9548 which creates up 
+to eight channels (think of it as I2C subnets) which can use the complete 
+address range of the device. 
+
+Drawback of using a multiplexer is that it takes more administration in 
+your code e.g. which device is on which channel. 
+This will slow down the access, which must be taken into account when
+deciding which devices are on which channel.
+Also note that switching between channels will slow down other devices 
+too if they are behind the multiplexer.
+
+- https://github.com/RobTillaart/TCA9548
+
+
 #### Connection
 
 Always check datasheet!
@@ -148,7 +169,8 @@ and should only be used if you are in a need for speed.
 #### Constructor
 
 - **DHT20(TwoWire \*wire = &Wire)** constructor, using a specific Wire (I2C bus).
-- **bool begin()** initializer for non ESP32. Returns true if connected.
+- **bool begin()** initializer. Returns true if connected.
+The user must call **Wire.begin()** before calling this function.
 - **bool isConnected()** returns true if the address of the DHT20 can be seen on the I2C bus.
 - **uint8_t getAddress()** returns the (fixed) address - convenience.
 
@@ -251,6 +273,8 @@ the read calls. (0.2.0)
 #### Must
 
 - improve documentation.
+- sync AM2315C developments
+  - see https://github.com/RobTillaart/AM2315C
 - investigate the bug from #8 further
   (is done in 0.2.1 see issue #8)
 
@@ -284,4 +308,3 @@ donate through PayPal or GitHub sponsors.
 
 Thank you,
 
-
diff --git a/examples/DHT20/DHT20.ino b/examples/DHT20/DHT20.ino
index 28388a8..de1a1a8 100644
--- a/examples/DHT20/DHT20.ino
+++ b/examples/DHT20/DHT20.ino
@@ -2,6 +2,7 @@
 //    FILE: DHT20.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for DHT20 I2C humidity & temperature sensor
+//     URL: https://github.com/RobTillaart/DHT20
 //
 //  Always check datasheet - front view
 //
@@ -19,6 +20,7 @@ DHT20 DHT;
 
 uint8_t count = 0;
 
+
 void setup()
 {
   Serial.begin(115200);
diff --git a/examples/DHT20_I2C_speed/DHT20_I2C_speed.ino b/examples/DHT20_I2C_speed/DHT20_I2C_speed.ino
index 26cd077..23dba0c 100644
--- a/examples/DHT20_I2C_speed/DHT20_I2C_speed.ino
+++ b/examples/DHT20_I2C_speed/DHT20_I2C_speed.ino
@@ -2,6 +2,7 @@
 //    FILE: DHT20_I2C_speed.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for DHT20 I2C humidity & temperature sensor
+//     URL: https://github.com/RobTillaart/DHT20
 //
 //  Always check datasheet - front view
 //
@@ -14,12 +15,14 @@
 
 //  NOTE datasheet states 400 KHz as maximum
 
+
 #include "DHT20.h"
 
 DHT20 DHT;
 
 uint32_t start, stop;
 
+
 void setup()
 {
   Serial.begin(115200);
@@ -58,7 +61,7 @@ void setup()
 
     Serial.print(speed);
     Serial.print("\t");
-    Serial.print(stop - start);  // time
+    Serial.print(stop - start);  //  time
     Serial.print("\t");
     Serial.print(DHT.getHumidity(), 1);
     Serial.print("\t");
diff --git a/examples/DHT20_async/DHT20_async.ino b/examples/DHT20_async/DHT20_async.ino
index c197c43..f26b5e6 100644
--- a/examples/DHT20_async/DHT20_async.ino
+++ b/examples/DHT20_async/DHT20_async.ino
@@ -2,6 +2,7 @@
 //    FILE: DHT20_async.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for DHT20 I2C humidity & temperature sensor
+//     URL: https://github.com/RobTillaart/DHT20
 //
 //  Always check datasheet - front view
 //
@@ -19,6 +20,7 @@ DHT20 DHT;
 
 uint32_t counter = 0;
 
+
 void setup()
 {
   Serial.begin(115200);
diff --git a/examples/DHT20_lcd/DHT20_lcd.ino b/examples/DHT20_lcd/DHT20_lcd.ino
index 0cc712d..96b2bc3 100644
--- a/examples/DHT20_lcd/DHT20_lcd.ino
+++ b/examples/DHT20_lcd/DHT20_lcd.ino
@@ -2,6 +2,7 @@
 //    FILE: DHT20_lcd.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for DHT20 I2C humidity & temperature sensor
+//     URL: https://github.com/RobTillaart/DHT20
 //
 //  Always check datasheet - front view
 //
diff --git a/examples/DHT20_offset/DHT20_offset.ino b/examples/DHT20_offset/DHT20_offset.ino
index 3d30ca5..859255e 100644
--- a/examples/DHT20_offset/DHT20_offset.ino
+++ b/examples/DHT20_offset/DHT20_offset.ino
@@ -2,6 +2,7 @@
 //    FILE: DHT20_offset.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for DHT20 I2C humidity & temperature sensor
+//     URL: https://github.com/RobTillaart/DHT20
 //
 //  Always check datasheet - front view
 //
diff --git a/examples/DHT20_plotter/DHT20_plotter.ino b/examples/DHT20_plotter/DHT20_plotter.ino
index c0adbfe..d1414f2 100644
--- a/examples/DHT20_plotter/DHT20_plotter.ino
+++ b/examples/DHT20_plotter/DHT20_plotter.ino
@@ -2,6 +2,7 @@
 //    FILE: DHT20_plotter.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for DHT20 I2C humidity & temperature sensor
+//     URL: https://github.com/RobTillaart/DHT20
 //
 //  Always check datasheet - front view
 //
diff --git a/examples/DHT20_read_status/DHT20_read_status.ino b/examples/DHT20_read_status/DHT20_read_status.ino
index f751fd8..d1988b6 100644
--- a/examples/DHT20_read_status/DHT20_read_status.ino
+++ b/examples/DHT20_read_status/DHT20_read_status.ino
@@ -2,6 +2,7 @@
 //    FILE: DHT20_read_status.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for DHT20 I2C humidity & temperature sensor
+//     URL: https://github.com/RobTillaart/DHT20
 //
 //  Always check datasheet - front view
 //
@@ -19,6 +20,7 @@ DHT20 DHT;
 
 uint8_t count = 0;
 
+
 void setup()
 {
   Serial.begin(115200);
diff --git a/examples/DHT20_test_esp/DHT20_test_esp.ino b/examples/DHT20_test_esp/DHT20_test_esp.ino
index d49d19d..6c9a4b5 100644
--- a/examples/DHT20_test_esp/DHT20_test_esp.ino
+++ b/examples/DHT20_test_esp/DHT20_test_esp.ino
@@ -2,8 +2,8 @@
 //    FILE: DHT20_test_esp.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for DHT20 I2C humidity & temperature sensor
+//     URL: https://github.com/RobTillaart/DHT20
 //
-
 //  Always check datasheet - front view
 //
 //          +--------------+
diff --git a/examples/DHT20_test_rp2040/DHT20_test_rp2040.ino b/examples/DHT20_test_rp2040/DHT20_test_rp2040.ino
index 9688687..2ad8698 100644
--- a/examples/DHT20_test_rp2040/DHT20_test_rp2040.ino
+++ b/examples/DHT20_test_rp2040/DHT20_test_rp2040.ino
@@ -2,8 +2,8 @@
 //    FILE: DHT20_test_rp2040.ino
 //  AUTHOR: Rob Tillaart
 // PURPOSE: Demo for DHT20 I2C humidity & temperature sensor
+//     URL: https://github.com/RobTillaart/DHT20
 //
-
 //  Always check datasheet - front view
 //
 //          +--------------+
diff --git a/library.json b/library.json
index 2fce220..a8c51fd 100644
--- a/library.json
+++ b/library.json
@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/DHT20.git"
   },
-  "version": "0.3.0",
+  "version": "0.3.1",
   "license": "MIT",
   "frameworks": "*",
   "platforms": "*",
diff --git a/library.properties b/library.properties
index 6ea1930..41aa1ef 100644
--- a/library.properties
+++ b/library.properties
@@ -1,5 +1,5 @@
 name=DHT20
-version=0.3.0
+version=0.3.1
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino library for I2C DHT20 temperature and humidity sensor. 
diff --git a/test/unit_test_001.cpp b/test/unit_test_001.cpp
index c6f8782..484233e 100644
--- a/test/unit_test_001.cpp
+++ b/test/unit_test_001.cpp
@@ -25,7 +25,6 @@
 #include <ArduinoUnitTests.h>
 
 
-#include "Wire.h"
 #include "DHT20.h"