diff --git a/libraries/MCP9808_RT/.arduino-ci.yml b/libraries/MCP9808_RT/.arduino-ci.yml
index cecf5850..25980972 100644
--- a/libraries/MCP9808_RT/.arduino-ci.yml
+++ b/libraries/MCP9808_RT/.arduino-ci.yml
@@ -1,3 +1,18 @@
+platforms:
+  rpipico:
+    board: rp2040:rp2040:rpipico
+    package: rp2040:rp2040
+    gcc:
+      features:
+      defines:
+        - ARDUINO_ARCH_RP2040
+      warnings:
+      flags:
+
+packages:
+  rp2040:rp2040:
+    url: https://github.com/earlephilhower/arduino-pico/releases/download/global/package_rp2040_index.json
+
 compile:
   # Choosing to run compilation tests on 2 different Arduino platforms
   platforms:
@@ -9,3 +24,4 @@ compile:
     - esp32
     # - esp8266
     # - mega2560
+    - rpipico
diff --git a/libraries/MCP9808_RT/CHANGELOG.md b/libraries/MCP9808_RT/CHANGELOG.md
new file mode 100644
index 00000000..1815a7c4
--- /dev/null
+++ b/libraries/MCP9808_RT/CHANGELOG.md
@@ -0,0 +1,44 @@
+# Change Log MCP9808_RT
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](http://keepachangelog.com/)
+and this project adheres to [Semantic Versioning](http://semver.org/).
+
+
+## [0.2.2] - 2022-11-17
+- add RP2040 in build-CI
+- add changelog.md
+- edit readme.md
+
+
+## [0.2.1] - 2021-12-21
+- update library.json
+- update license
+- minor edits
+
+## [0.2.0] - 2021-11-19
+- fix #7 negative temperature
+
+----
+
+## [0.1.4] - 2021-11-08
+- update build-CI, badges
+- default offset for offset
+- default Wire for I2C bus - setAddress()
+
+## [0.1.3] - 2021-01-01
+- Arduino-ci + unit test
+
+## [0.1.2] - 2020-11-16
+- removed hasAlert
+- removed setAlertPin, 
+- added 2 alert examples
+- refactor low level
+
+## [0.1.1] - 2020-11-12
+- refactor
+
+## [0.1.0] - 2020-05-03
+- initial version.
+
diff --git a/libraries/MCP9808_RT/README.md b/libraries/MCP9808_RT/README.md
index 6af97975..ad0c27a6 100644
--- a/libraries/MCP9808_RT/README.md
+++ b/libraries/MCP9808_RT/README.md
@@ -21,19 +21,19 @@ of electronics if the temperature hits a predefined value or zone.
 ### MCP9808 breakout board
 ```
 //
-//  Adafruit MCP9808 breakout board
-//  +----------+
-//  |0   ALERT |---------------+--[ 4K7 ]---- +5V
-//  |       A2 |---- GND       |
-//  |       A1 |---- GND       +--[ LED ]---- GND  // or other electronics.
-//  |       A0 |---- GND
-//  |      SDA |---- I2C MCU
-//  |      SCL |---- I2C MCU
-//  |      GND |---- GND MCU
-//  |0     VCC |---- +5V
-//  +----------+
+//       Adafruit MCP9808 breakout board
+//       +----------+
+//       |0   ALERT |---------------+--[ 4K7 ]---- +5V
+//       |       A2 |---- GND       |
+//       |       A1 |---- GND       +--[ LED ]---- GND  // or other electronics.
+//       |       A0 |---- GND
+//       |      SDA |---- I2C MCU
+//       |      SCL |---- I2C MCU
+//       |      GND |---- GND MCU
+//       |0     VCC |---- +5V
+//       +----------+
 //
-//  address above is 24
+//       address above is 24
 //
 ```
 
@@ -50,7 +50,7 @@ Default I2C bus is Wire.
 
 #### Address
 
-There ar max 8 sensors on one I2C bus.
+There are max 8 sensors on one I2C bus.
 Normal address = 0011xxx where xxx = A2, A1, A0  
 
 | Address |  HEX   |  A2  |  A1  |  A0  |
@@ -80,11 +80,11 @@ The value returned by **getStatus()** is the last value read by the call to **Ge
 There are three bits, see table below. 
 A value of 6 == mask == 110 means that TA is above the upper and above the critical temperature.
 
-| Bit  |  Mask  | Description | Notes           |
-|:----:|:------:|:------------|:----------------|
-| 0    |  0x01  | TA < TLOWER | lower           |
-| 1    |  0x02  | TA > TUPPER | larger          |
-| 2    |  0x04  | TA ≥ TCRIT  | larger or equal |
+|  Bit  |  Mask  |  Description  |  Notes           |
+|:-----:|:------:|:--------------|:-----------------|
+|   0   |  0x01  |  TA < TLOWER  |  lower           |
+|   1   |  0x02  |  TA > TUPPER  |  larger          |
+|   2   |  0x04  |  TA ≥ TCRIT   |  larger or equal |
 
 
 ### Resolution
@@ -92,12 +92,12 @@ A value of 6 == mask == 110 means that TA is above the upper and above the criti
 - **void setResolution(uint8_t resolution = 3)** set the resolution, if resolution > 3, it is not set.
 - **uint8_t getResolution()** returns the resolution set.
 
-| Value  | Resolution | Conv time (ms) | Samples/s | Notes   |
-|:------:|:-----------|:--------------:|:---------:|:-------:|
-| 0      | 0.5°C      | 30             | 33        |         |
-| 1      | 0.25°C     | 65             | 15        |         |
-| 2      | 0.125°C    | 130            | 7         |         |
-| 3      | 0.0625°C   | 250            | 4         | default |
+|  Value  |  Resolution  |  Conv time (ms)  |  Samples/s  |  Notes   |
+|:-------:|:-------------|:----------------:|:-----------:|:--------:|
+|    0    |  0.5°C       |   30             |   33        |          |
+|    1    |  0.25°C      |   65             |   15        |          |
+|    2    |  0.125°C     |   130            |   7         |          |
+|    3    |  0.0625°C    |   250            |   4         |  default |
 
 
 Note: for the same resolution it is about 3x faster than a DS18B20.
@@ -112,7 +112,7 @@ Note: for the same resolution it is about 3x faster than a DS18B20.
 |:-----:|:------:|:-----------|:----------------|:-------|
 | 0     | 0x0001 | ALT MOD    | alert mode      | **0 = comparator output**,  1 = interrupt output
 | 1     | 0x0002 | ALT POL    | alert polarity  | **0 = active low**,         1 = active high
-| 2     | 0x0004 | ALT SEL    | alert select    | **0 = upper+lower+crit**,   1 = crit only
+| 2     | 0x0004 | ALT SEL    | alert select    | **0 = upper+lower+crit**,   1 = critical only
 | 3     | 0x0008 | ALT CNT    | alert control   | **0 = OFF**,                1 = ON
 | 4     | 0x0010 | ALT STAT   | alert status    | **0 = OFF**,                1 = ON  (read!)
 | 5     | 0x0020 | INT CLR    | interrupt clear | **0 = none**,               1 = clear interrupt
@@ -163,8 +163,19 @@ See examples
 
 ## Future
 
+#### must
 - update documentation
-- do unit test
-- add more examples for the **ALERT**
--
+  - compare DS18B20?
+- test more
+  - negative temperatures
+
+#### should
+- do unit test
+- check for optimizations
+
+#### could
+- add examples 
+  - for the **ALERT**
+  - multi sensor
+
 
diff --git a/libraries/MCP9808_RT/library.json b/libraries/MCP9808_RT/library.json
index aae538a9..d99f434e 100644
--- a/libraries/MCP9808_RT/library.json
+++ b/libraries/MCP9808_RT/library.json
@@ -15,7 +15,7 @@
     "type": "git",
     "url": "https://github.com/RobTillaart/MCP9808_RT.git"
   },
-  "version": "0.2.1",
+  "version": "0.2.2",
   "license": "MIT",
   "frameworks": "arduino",
   "platforms": "*",
diff --git a/libraries/MCP9808_RT/library.properties b/libraries/MCP9808_RT/library.properties
index 6585c815..1269902f 100644
--- a/libraries/MCP9808_RT/library.properties
+++ b/libraries/MCP9808_RT/library.properties
@@ -1,5 +1,5 @@
 name=MCP9808_RT
-version=0.2.1
+version=0.2.2
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Arduino Library for I2C MCP9808 temperature sensor
diff --git a/libraries/MCP9808_RT/mcp9808.cpp b/libraries/MCP9808_RT/mcp9808.cpp
index 1c6823c9..2e2c7435 100644
--- a/libraries/MCP9808_RT/mcp9808.cpp
+++ b/libraries/MCP9808_RT/mcp9808.cpp
@@ -1,22 +1,10 @@
 //
 //    FILE: mcp9808.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.2.1
+// VERSION: 0.2.2
 // PURPOSE: Arduino Library for I2C mcp9808 temperature sensor
 //    DATE: 2020-05-03
 //     URL: https://github.com/RobTillaart/MCP9808_RT
-//
-//  HISTORY:
-//  0.1.0   2020-05-03  initial version
-//  0.1.1   2020-11-12  refactor
-//  0.1.2   2020-11-16  removed hasAlert, removed setAlertPin, 
-//                      added 2 alert examples, refactor low level
-//  0.1.3   2021-01-01  Arduino-ci + unit test
-//  0.1.4   2021-11-08  update build-CI, badges
-//                      default offset for offset
-//                      default Wire for I2C bus - setAddress()
-//  0.2.0   2021-11-19  fix #7 negative temperature
-//  0.2.1   2021-12-21  update library.json, license, minor edits
 
 
 #include "mcp9808.h"
@@ -33,16 +21,16 @@
 
 
 /*
-  0000 = RFU, Reserved for Future Use (Read-Only register)
-  0001 = Configuration register (CONFIG)
-  0010 = Alert Temperature Upper Boundary Trip register (TUPPER)
-  0011 = Alert Temperature Lower Boundary Trip register (TLOWER)
-  0100 = Critical Temperature Trip register (TCRIT)
-  0101 = Temperature register (TA)
-  0110 = Manufacturer ID register
-  0111 = Device ID/Revision register
-  1000 = Resolution register
-  1xxx = Reserved(1)
+    0000  =  RFU, Reserved for Future Use (Read-Only register)
+    0001  =  Configuration register (CONFIG)
+    0010  =  Alert Temperature Upper Boundary Trip register (TUPPER)
+    0011  =  Alert Temperature Lower Boundary Trip register (TLOWER)
+    0100  =  Critical Temperature Trip register (TCRIT)
+    0101  =  Temperature register (TA)
+    0110  =  Manufacturer ID register
+    0111  =  Device ID/Revision register
+    1000  =  Resolution register
+    1xxx  =  Reserved(1)
 */
 
 
@@ -195,7 +183,7 @@ uint16_t MCP9808::getRFU()
 
 ////////////////////////////////////////////////////////////////
 //
-// PRIVATE
+//  PRIVATE
 //
 void MCP9808::writeFloat(uint8_t reg, float f)
 {
@@ -214,7 +202,7 @@ float MCP9808::readFloat(uint8_t reg)
   {
     _status = (val & 0xE000) >> 13;
   }
-  if (val & 0x1000)  // negative value
+  if (val & 0x1000)         //  negative value
   {
     return ((val & 0x0FFF) * 0.0625) - 256.0;
   }
@@ -224,7 +212,7 @@ float MCP9808::readFloat(uint8_t reg)
 
 void MCP9808::writeReg8(uint8_t reg, uint8_t value)
 {
-  if (reg > MCP9808_RES) return;  // see p.16
+  if (reg > MCP9808_RES) return;      //  see p.16
   Wire.beginTransmission(_address);
   Wire.write(reg);
   Wire.write(value);
@@ -234,7 +222,7 @@ void MCP9808::writeReg8(uint8_t reg, uint8_t value)
 
 uint8_t MCP9808::readReg8(uint8_t reg)
 {
-  if (reg > MCP9808_RES) return 0;  // see p.16
+  if (reg > MCP9808_RES) return 0;    //  see p.16
   Wire.beginTransmission(_address);
   Wire.write(reg);
   Wire.endTransmission();
@@ -245,18 +233,18 @@ uint8_t MCP9808::readReg8(uint8_t reg)
 
 void MCP9808::writeReg16(uint8_t reg, uint16_t value)
 {
-  if (reg > MCP9808_RES) return;  // see p.16
+  if (reg > MCP9808_RES) return;      //  see p.16
   Wire.beginTransmission(_address);
   Wire.write(reg);
-  Wire.write(value >> 8);   // hi byte
-  Wire.write(value & 0xFF); // lo byte
+  Wire.write(value >> 8);       //  hi byte
+  Wire.write(value & 0xFF);     //  lo byte
   Wire.endTransmission();
 }
 
 
 uint16_t MCP9808::readReg16(uint8_t reg)
 {
-  if (reg > MCP9808_RES) return 0;  // see p.16
+  if (reg > MCP9808_RES) return 0;    //  see p.16
   Wire.beginTransmission(_address);
   Wire.write(reg);
   Wire.endTransmission();
diff --git a/libraries/MCP9808_RT/mcp9808.h b/libraries/MCP9808_RT/mcp9808.h
index f2d8a2a7..53cd11c6 100644
--- a/libraries/MCP9808_RT/mcp9808.h
+++ b/libraries/MCP9808_RT/mcp9808.h
@@ -2,7 +2,7 @@
 //
 //    FILE: mcp9808.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.2.1
+// VERSION: 0.2.2
 // PURPOSE: Arduino Library for I2C mcp9808 temperature sensor
 //    DATE: 2020-05-03
 //     URL: https://github.com/RobTillaart/MCP9808_RT
@@ -12,16 +12,16 @@
 #include "Arduino.h"
 #include "Wire.h"
 
-// VALID ADDRESSES,
-// max 8 sensors on one bus
-// 24..31 == 0x18..0x1F
+//  VALID ADDRESSES,
+//  max 8 sensors on one bus
+//  24..31  ==  0x18..0x1F
 
 
-#define MCP9808_LIB_VERSION               (F("0.2.1"))
+#define MCP9808_LIB_VERSION               (F("0.2.2"))
 
 
-// CONFIGURATION REGISTER MASKS
-// check the datasheet for exact usage
+//  CONFIGURATION REGISTER MASKS
+//  check the datasheet for exact usage
 #define MCP9808_THYSTERESIS               0x0600
 #define MCP9808_SHUTDOWN                  0x0100
 #define MCP9808_CRIT_LOCK                 0x0080
@@ -38,7 +38,7 @@ class MCP9808
 {
 public:
 #if defined(ESP8266) || defined(ESP32)
-  // dataPin and clockPin can be used for ESP8266
+  //  dataPin and clockPin can be used for ESP8266
   MCP9808(const uint8_t address, const uint8_t dataPin = 255, const uint8_t clockPin = 255);
 #else
   MCP9808(const uint8_t address);
@@ -61,8 +61,8 @@ public:
   float     getOffset();
   float     getTemperature();
 
-  // getStatus() returns 0..7
-  // to get latest status, getTemperature() must be called first 
+  //  getStatus() returns 0..7
+  //  to get latest status, getTemperature() must be called first 
   uint8_t   getStatus();
 
   void      setResolution(uint8_t resolution = 3);
@@ -72,13 +72,13 @@ public:
   uint8_t   getDeviceID();
   uint8_t   getRevision();
 
-  // Reserved Register, not used
+  //  Reserved Register, not used
   uint16_t  getRFU();
 
 
 private:
   float     _offset = 0;
-  uint8_t   _status = 0;     // 0..7
+  uint8_t   _status = 0;     //  0..7
   uint8_t   _address;
   TwoWire*  _wire;