diff --git a/libraries/MS5837/.arduino-ci.yml b/libraries/MS5837/.arduino-ci.yml
new file mode 100644
index 00000000..77a333f9
--- /dev/null
+++ b/libraries/MS5837/.arduino-ci.yml
@@ -0,0 +1,28 @@
+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:
+    - uno
+    # - due
+    # - zero
+    # - leonardo
+    - m4
+    - esp32
+    - esp8266
+    # - mega2560
+    - rpipico
+
diff --git a/libraries/MS5837/.github/FUNDING.yml b/libraries/MS5837/.github/FUNDING.yml
new file mode 100644
index 00000000..90d9ab4c
--- /dev/null
+++ b/libraries/MS5837/.github/FUNDING.yml
@@ -0,0 +1,4 @@
+# These are supported funding model platforms
+
+github: RobTillaart
+
diff --git a/libraries/MS5837/.github/workflows/arduino-lint.yml b/libraries/MS5837/.github/workflows/arduino-lint.yml
new file mode 100644
index 00000000..8a26f14a
--- /dev/null
+++ b/libraries/MS5837/.github/workflows/arduino-lint.yml
@@ -0,0 +1,13 @@
+
+name: Arduino-lint
+
+on: [push, pull_request]
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: arduino/arduino-lint-action@v1
+        with:
+          library-manager: update
+          compliance: strict
diff --git a/libraries/MS5837/.github/workflows/arduino_test_runner.yml b/libraries/MS5837/.github/workflows/arduino_test_runner.yml
new file mode 100644
index 00000000..fadfa904
--- /dev/null
+++ b/libraries/MS5837/.github/workflows/arduino_test_runner.yml
@@ -0,0 +1,17 @@
+---
+name: Arduino CI
+
+on: [push, pull_request]
+
+jobs:
+  runTest:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 2.6
+      - run: |
+          gem install arduino_ci
+          arduino_ci.rb
diff --git a/libraries/MS5837/.github/workflows/jsoncheck.yml b/libraries/MS5837/.github/workflows/jsoncheck.yml
new file mode 100644
index 00000000..37a11298
--- /dev/null
+++ b/libraries/MS5837/.github/workflows/jsoncheck.yml
@@ -0,0 +1,18 @@
+name: JSON check
+
+on:
+  push:
+    paths:
+      - '**.json'
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: json-syntax-check
+        uses: limitusus/json-syntax-check@v1
+        with:
+          pattern: "\\.json$"
+
diff --git a/libraries/MS5837/CHANGELOG.md b/libraries/MS5837/CHANGELOG.md
new file mode 100644
index 00000000..2bad746d
--- /dev/null
+++ b/libraries/MS5837/CHANGELOG.md
@@ -0,0 +1,16 @@
+# Change Log MS5837
+
+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/).
+
+
+## [0.1.0] - 2023-12-24
+- initial release
+
+## [0.0.0] - 2023-11-12
+- initial version
+
+
+
diff --git a/libraries/MS5837/LICENSE b/libraries/MS5837/LICENSE
new file mode 100644
index 00000000..16ef1551
--- /dev/null
+++ b/libraries/MS5837/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023-2023 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
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/libraries/MS5837/MS5837.cpp b/libraries/MS5837/MS5837.cpp
new file mode 100644
index 00000000..728b26a1
--- /dev/null
+++ b/libraries/MS5837/MS5837.cpp
@@ -0,0 +1,279 @@
+//
+//    FILE: MS5837.cpp
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+//    DATE: 2023-11-12
+// PURPOSE: Arduino library for MS5837 temperature and pressure sensor.
+//     URL: https://github.com/RobTillaart/MS5837
+
+
+#include "MS5837.h"
+
+//  commands  (MS5611 alike)
+#define MS5837_CMD_READ_ADC       0x00
+#define MS5837_CMD_READ_PROM      0xA0
+#define MS5837_CMD_RESET          0x1E
+#define MS5837_CMD_CONVERT_D1     0x4A  //  differs from MS5611
+#define MS5837_CMD_CONVERT_D2     0x5A  //  differs from MS5611
+
+
+//  CONSTRUCTOR
+MS5837::MS5837(TwoWire *wire)
+{
+  _wire = wire;
+}
+
+bool MS5837::begin(uint8_t mathMode)
+{
+  if (! isConnected()) return false;
+  reset(mathMode);
+
+  return true;
+}
+
+bool MS5837::isConnected()
+{
+  _wire->beginTransmission(_address);
+  return ( _wire->endTransmission() == 0);
+}
+
+bool MS5837::reset(uint8_t mathMode)
+{
+  command(MS5837_CMD_RESET);
+  uint32_t start = millis();
+  //  while loop prevents blocking RTOS
+  while (micros() - start < 10)
+  {
+    yield();
+    delay(1);
+  }
+
+  initConstants(mathMode);
+
+  //  SKIP CRC check
+
+  //  derive the type from mathMode instead of the other way around.
+  //  user must
+  _type = MS5837_TYPE_30;
+  if (mathMode == 1) _type = MS5837_TYPE_02;
+  if (mathMode == 2) _type = MS5803_TYPE_01;
+  return true;
+}
+
+uint8_t MS5837::getType()
+{
+  return _type;
+}
+
+uint8_t MS5837::getAddress()
+{
+  return _address;
+}
+
+
+//////////////////////////////////////////////////////////////////////
+//
+//  READ
+//
+bool MS5837::read(uint8_t bits)
+{
+  if (isConnected() == false) return false;
+
+  int index = constrain(bits, 8, 13);
+  index -= 8;
+  uint8_t waitMillis[6] = { 1, 2, 3, 5, 9, 18 };
+  uint8_t wait = waitMillis[index];
+  
+   //  D1 conversion
+  _wire->beginTransmission(_address);
+  _wire->write(MS5837_CMD_CONVERT_D1 + index * 2);
+  _wire->endTransmission();  //  TODO check all of these
+
+  uint32_t start = millis();
+
+  //  while loop prevents blocking RTOS
+  while (micros() - start < wait)
+  {
+    yield();
+    delay(1);
+  }
+  //  NOTE: D1 and D2 are reserved in MBED (NANO BLE)
+  uint32_t _D1 = readADC();
+
+   //  D2 conversion
+  _wire->beginTransmission(_address);
+  _wire->write(MS5837_CMD_CONVERT_D2 + index * 2);
+  _wire->endTransmission();
+
+  start = millis();
+  //  while loop prevents blocking RTOS
+  while (micros() - start < wait)
+  {
+    yield();
+    delay(1);
+  }
+
+  //  NOTE: D1 and D2 are reserved in MBED (NANO BLE)
+  uint32_t _D2 = readADC();
+
+  float dT = _D2 - C[5];
+  _temperature = 2000 + dT * C[6];
+
+  float offset = C[2] + dT * C[4];
+  float sens   = C[1] + dT * C[3];
+  _pressure = _D1 * sens + offset;
+
+
+  //  Second order compensation
+  if (_temperature < 20)
+  {
+    float ti = dT * dT * (11 * 2.91038304567E-11);  //  1 / 2^35
+    float t = (_temperature - 2000) * (_temperature - 2000);
+    float offset2 = t * (31 * 0.125);  //  1 / 2^3
+    float sens2 = t * (63 * 0.03125);  //  1 / 2^5
+
+    offset       -= offset2;
+    sens         -= sens2;
+    _temperature -= ti;
+  }
+  //                         1 / 2^21                    C[7] / 100
+  _pressure = (_D1 * sens * 4.76837158203E-7 - offset) * C[7] * 0.01;
+  _temperature *= 0.01;
+
+  return true;
+}
+
+
+float MS5837::getPressure()
+{
+  return _pressure;
+}
+
+float MS5837::getTemperature()
+{
+  return _temperature;
+}
+
+
+//  https://www.mide.com/air-pressure-at-altitude-calculator
+//  https://community.bosch-sensortec.com/t5/Question-and-answers/How-to-calculate-the-altitude-from-the-pressure-sensor-data/qaq-p/5702
+//
+float MS5837::getAltitude(float airPressure)
+{
+  float ratio = _pressure / airPressure;
+	return 44330 * (1 - pow(ratio, 0.190294957));
+}
+
+
+
+//////////////////////////////////////////////////////////////////////
+//
+//  DENSITY for depth
+//
+void MS5837::setDensity(float density)
+{
+  _density = density;
+}
+
+float MS5837::getDensity()
+{
+  return _density;
+}
+
+float MS5837::getDepth(float airPressure)
+{
+  //  9.80665 == Gravity constant.
+  //  1 / (_density * 9.80665 * 10)  can be pre-calculated and cached in setDensity.
+  //
+  //  delta P = rho * g * h  => h = delta P / rho * g
+  //  pressure = mbar, density grams/cm3 => correction factor 0.1 (=1/10)
+  return (_pressure - airPressure)/(_density * 9.80665 * 10);
+}
+
+
+
+//////////////////////////////////////////////////////////////////////
+//
+//  PROTECTED
+//
+int MS5837::command(uint8_t cmd)
+{
+  yield();
+  _wire->beginTransmission(_address);
+  _wire->write(cmd);
+  _result = _wire->endTransmission();
+  return _result;
+}
+
+
+void MS5837::initConstants(uint8_t mathMode)
+{
+  //  Constants that were multiplied in read() - datasheet page 8
+  //  do this once and you save CPU cycles.
+  //
+  //  datasheet MS5837_30  page 7
+  //
+  //                          mathMode = 0;           |   = 1
+  C[0] = 1;
+  C[1] = 32768L;          //  SENSt1   = C[1] * 2^15  |  * 2^16
+  C[2] = 65536L;          //  OFFt1    = C[2] * 2^16  |  * 2^17
+  C[3] = 3.90625E-3;      //  TCS      = C[3] / 2^8   |  / 2^7
+  C[4] = 7.8125E-3;       //  TCO      = C[4] / 2^7   |  / 2^6
+  C[5] = 256;             //  Tref     = C[5] * 2^8   |  * 2^8
+  C[6] = 1.1920928955E-7; //  TEMPSENS = C[6] / 2^23  |  / 2^23
+  C[7] = 1.220703125E-4;  //  compensate uses / 2^13  |  / 2^15
+
+  //  Appnote version for pressure.
+  //  adjustments for MS5837_02
+  if (mathMode == 1)
+  {
+    C[1] *= 2;  //  SENSt1
+    C[2] *= 2;  //  OFFt1
+    C[3] *= 2;  //  TCS
+    C[4] *= 2;  //  TCO
+    C[7] /= 4;  //  compensation code has factor 4.
+  }
+
+  //  adjustments for MS5803_01
+  if (mathMode == 2)
+  {
+    C[7] /= 4;  //  compensation code has factor 4.
+  }
+
+
+  for (uint8_t i = 0; i < 7 ; i++)
+  {
+    _wire->beginTransmission(_address);
+    _wire->write(MS5837_CMD_READ_PROM + i + i);
+    _wire->endTransmission();
+    uint8_t length = 2;
+    _wire->requestFrom(_address, length);
+    uint16_t tmp = _wire->read() << 8;
+    tmp |= _wire->read();
+    C[i] *= tmp;
+  }
+}
+
+
+uint32_t MS5837::readADC()
+{
+  command(MS5837_CMD_READ_ADC);
+  if (_result == 0)
+  {
+    uint8_t length = 3;
+    int bytes = _wire->requestFrom(_address, length);
+    if (bytes >= length)
+    {
+      uint32_t value = _wire->read() * 65536UL;
+      value += _wire->read() * 256UL;
+      value += _wire->read();
+      return value;
+    }
+    return 0UL;
+  }
+  return 0UL;
+}
+
+
+//  -- END OF FILE --
+
diff --git a/libraries/MS5837/MS5837.h b/libraries/MS5837/MS5837.h
new file mode 100644
index 00000000..990abe90
--- /dev/null
+++ b/libraries/MS5837/MS5837.h
@@ -0,0 +1,103 @@
+#pragma once
+//
+//    FILE: MS5837.h
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+//    DATE: 2023-11-12
+// PURPOSE: Arduino library for MS5837 temperature and pressure sensor.
+//     URL: https://github.com/RobTillaart/MS5837
+
+
+#include "Arduino.h"
+#include "Wire.h"
+
+
+//  TODO OSR factor in code?
+
+
+#define MS5837_LIB_VERSION        (F("0.1.0"))
+
+
+#define MS5803_TYPE_01             1
+#define MS5837_TYPE_02             2
+#define MS5837_TYPE_30            30
+
+
+class MS5837
+{
+public:
+  MS5837(TwoWire *wire = &Wire);
+
+  //  MS5837-30bar = 0
+  //  MS5837-02bar = 1
+  bool    begin(uint8_t mathMode);
+  bool    isConnected();
+  bool    reset(uint8_t mathMode);
+  uint8_t getType();
+  uint8_t getAddress();
+
+
+  //////////////////////////////////////////////////////////////////////
+  //
+  //  READ
+  //
+  // call will block 3-40 milliseconds, depends on # bits.
+  // bits = 8-12   (8-13 for the MS5837_02)
+  bool    read(uint8_t bits = 8);
+  //  see https://github.com/RobTillaart/pressure for conversions.
+  //  returns mBar
+  float   getPressure();
+  //  see https://github.com/RobTillaart/temperature for conversions.
+  //  returns Celsius
+  float   getTemperature();
+  //      compensate for actual air pressure if needed
+  float   getAltitude(float airPressure = 1013.25);
+
+
+  //////////////////////////////////////////////////////////////////////
+  //
+  //  DEPTH
+  //
+  //  density is temperature dependent, see
+  //  https://www.usgs.gov/special-topics/water-science-school/science/water-density
+  //
+  //  density water 20°C = 0.99802
+  //  density seawater is
+  //  density in grams / cm3  (so not in grams per liter
+  void    setDensity(float density = 0.99802);
+  float   getDensity();
+  //      returns meters (SI unit)
+  //      compensate for actual air pressure if needed
+  float   getDepth(float airPressure = 1013.25);
+
+
+protected:
+  int        command(uint8_t cmd);
+  void       initConstants(uint8_t mathMode);
+  uint32_t   readADC();
+
+
+  uint8_t   _address = 0x76;   //  fixed address
+  TwoWire * _wire = NULL;
+
+  float     _pressure;
+  float     _temperature;
+
+  float     C[8];
+  uint8_t   _type;
+  int       _result;
+
+  float     _density = 0.99802;  //  water at 20 °C
+};
+
+
+//////////////////////////////////////////////////////////////////////
+//
+//  DERIVED CLASSES
+//
+
+//  MS5837_30   MS5837_02  etc ?
+
+
+//  -- END OF FILE --
+
diff --git a/libraries/MS5837/README.md b/libraries/MS5837/README.md
new file mode 100644
index 00000000..93ea844c
--- /dev/null
+++ b/libraries/MS5837/README.md
@@ -0,0 +1,188 @@
+
+[![Arduino CI](https://github.com/RobTillaart/MS5837/workflows/Arduino%20CI/badge.svg)](https://github.com/marketplace/actions/arduino_ci)
+[![Arduino-lint](https://github.com/RobTillaart/MS5837/actions/workflows/arduino-lint.yml/badge.svg)](https://github.com/RobTillaart/MS5837/actions/workflows/arduino-lint.yml)
+[![JSON check](https://github.com/RobTillaart/MS5837/actions/workflows/jsoncheck.yml/badge.svg)](https://github.com/RobTillaart/MS5837/actions/workflows/jsoncheck.yml)
+[![GitHub issues](https://img.shields.io/github/issues/RobTillaart/MS5837.svg)](https://github.com/RobTillaart/MS5837/issues)
+
+[![License: MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://github.com/RobTillaart/MS5837/blob/master/LICENSE)
+[![GitHub release](https://img.shields.io/github/release/RobTillaart/MS5837.svg?maxAge=3600)](https://github.com/RobTillaart/MS5837/releases)
+[![PlatformIO Registry](https://badges.registry.platformio.org/packages/robtillaart/library/MS5837.svg)](https://registry.platformio.org/libraries/robtillaart/MS5837)
+
+
+# MS5837
+
+Library for the MS5837 temperature and pressure sensor and compatibles.
+
+
+## Description
+
+**Experimental**
+
+The MS5837 is a waterproof device to measure temperature and pressure to a high level
+of accuracy.
+From the pressure one can calculate the depth or the altitude of the sensor to some extend.
+- The MS5837_30 can go to depth of 300 meter (30 Bar).
+- The MS5837_02 is meant for altitude measurements as it can as low as 300 mBar.
+
+The library does not use the integer math from the datasheet but float math. 
+Assumption is that it reduces footprint and increases math speed.
+This will have an effect on the accuracy of the results, 
+although these are expected relative small. (to be investigated)
+
+
+#### Related
+
+- https://github.com/RobTillaart/pressure Conversions
+- https://github.com/RobTillaart/temperature Conversions
+- https://github.com/RobTillaart/MS5611 temperature and pressure sensor
+
+See also .h file
+
+
+#### Compatibles
+
+See mathType notes below.
+
+|  Sensor        | mathType |  Celsius °C  |  pressure mBar  |  Notes  |
+|:---------------|:--------:|:------------:|:---------------:|:-------:|
+|  MS5837-30bar  |    0     |  -20 to +85  |  0 to 30000     |  for depth
+|  MS5837-02bar  |    1     |  -20 to +85  |  300 to 1200    |  for altitude
+|  MS5803-01bar  |    2     |  -40 to +85  |  10 to 1300     |  investigate
+
+
+#### Pressure mathType 
+
+There are MS5837 compatibles for which the math for the pressure is different.
+See **AN520__004: C-code example for MS56xx, MS57xx (except analog sensor), and MS58xx series pressure sensors**
+The difference is in the constants (mostly powers of 2) used to calculate the pressure.
+
+The library implements **reset(uint8_t mathMode = 0)** to select the mathMode.
+- mathMode = 0 ==> datasheet MS5837_30  page 7
+- mathMode = 1 ==> datasheet MS5837_02  page 7
+- mathMode = 2 ==> datasheet MS5803_01  page 7
+
+- other values will act as 0
+
+
+#### Tests
+
+Library uses similar code as the tested MS5611 library.
+
+TODO: tests with hardware.
+
+The library is tested with the following boards: TODO
+
+As always feedback is welcome.
+Please let me know of other working platforms / processors (and failing ones!).
+
+
+
+##  I2C
+
+User has to call **Wire.begin()** (or equivalent) before calling **ms5611.begin(0)**
+
+
+#### Performance
+
+The maximum I2C speed is 400 KHz. (TODO verify).
+
+
+#### Multiplexing
+
+The MS5837 has one fixed address 0x76. So you can have only one per I2C bus.
+If one needs to control more MS5837's one need an I2C multiplexer.
+
+- https://github.com/RobTillaart/TCA9548 I2C multiplexer.
+
+
+## Interface
+
+```cpp
+#include MS5837.h
+```
+
+#### Constructor
+
+- **MS5837(TwoWire \* wire = &Wire))** constructor, optional 
+- **bool begin(uint8_t mathMode)** initializes the library.
+- **bool isConnected()** returns true if device visible on I2C bus.
+- **bool reset(uint8_t mathMode)** resets the sensor and reads its configuration.
+The mathMode must match the type of sensor, see table above.
+- **uint8_t getType()** type indicates max pressure. 
+Returns 30 or 2 or zero if unknown.
+- **uint8_t getAddress()** returns 0x76 as this is a fixed address.
+
+
+#### Temperature and Pressure
+
+- **bool read(uint8_t bits = 8)** the actual reading of the sensor. 
+The bits determines the oversampling factor, see table below. 
+Returns true upon success.
+The call will block for 3 to 40 milliseconds, depending upon number of bits.
+- **float getPressure()** returns mBar.
+- **float getTemperature()** returns degrees Celsius.
+- **float getAltitude(float airPressure = 1013.25)** calculates the altitude, based upon actual pressure and the pressure at sea level.
+Returns altitude in meters.
+One can compensate for the actual air pressure at sea level.
+
+|  type       |  bits read()  | 
+|:-----------:|:-------------:|
+|  MS5837_30  |  8..12        |
+|  MS5837_02  |  8..12, 13    |
+|  MS5803_01  |  8..12        |
+
+
+#### Depth
+
+Mainly for the MS5837_30.
+
+Depth calculation depends on the air pressure at sea level, and the density
+of the liquid you are submerged in (typical water).
+The pressure is in fact the sum of the air pressure and the weight of the liquid above.
+If the density is larger the maximum depth of the sensor will decrease.
+
+- **void setDensity(float density)** set liquid density.
+- **float getDensity()** returns set liquid density.
+- **float getDepth(float airPressure = 1013.25)** calculates the depth, 
+based upon actual pressure and the pressure at sea level.
+Returns depth in meters.
+One can compensate for the actual air pressure at sea level.
+
+
+## Future
+
+#### Must
+
+- documentation
+- buy hardware - 30 or 2 bar version ?
+- check TODO's in code / documentation
+- test 
+
+#### Should
+
+- add **lastRead()**
+- create derived classes?
+  - so one does not need to set mathMode.
+  - for 5803 
+- can we see conversion ready?
+- performance test
+- investigate the effects of float math on accuracy / precision.
+
+
+#### Could
+
+- refactor type & mathMode
+- add offset functions
+
+
+#### Won't (unless requested)
+
+
+## Support
+
+If you appreciate my libraries, you can support the development and maintenance.
+Improve the quality of the libraries by providing issues and Pull Requests, or
+donate through PayPal or GitHub sponsors.
+
+Thank you,
+
diff --git a/libraries/MS5837/examples/MS5837_demo/MS5837_demo.ino b/libraries/MS5837/examples/MS5837_demo/MS5837_demo.ino
new file mode 100644
index 00000000..2c304efb
--- /dev/null
+++ b/libraries/MS5837/examples/MS5837_demo/MS5837_demo.ino
@@ -0,0 +1,54 @@
+//    FILE: MS5837_demo.ino
+//  AUTHOR: Rob Tillaart
+// PURPOSE: demo MS5837 library
+//     URL: https://github.com/RobTillaart/MS5837
+
+
+#include "Arduino.h"
+#include "Wire.h"
+
+#include "MS5837.h"
+
+MS5837 MS(&Wire);
+
+
+void setup()
+{
+  Serial.begin(115200);
+  while (!Serial);
+  Serial.println(__FILE__);
+  Serial.print("MS5837_LIB_VERSION: ");
+  Serial.println(MS5837_LIB_VERSION);
+  Serial.println();
+
+  Wire.begin();
+  if (MS.begin(0) == true)
+  {
+    Serial.println("MS5837 found.");
+  }
+  else
+  {
+    Serial.println("MS5837 not found. halt.");
+    // while (1);
+  }
+  Serial.println();
+}
+
+
+void loop()
+{
+  MS.read();           //  note no error checking => "optimistic".
+  Serial.print("T:\t");
+  Serial.print(MS.getTemperature(), 2);
+  Serial.print("\tP:\t");
+  Serial.print(MS.getPressure(), 2);
+  Serial.print("\tA:\t");
+  Serial.print(MS.getAltitude(), 2);
+  Serial.print("\tD:\t");
+  Serial.print(MS.getDepth(), 2);
+  Serial.println();
+  delay(10000);
+}
+
+
+//  -- END OF FILE --
diff --git a/libraries/MS5837/keywords.txt b/libraries/MS5837/keywords.txt
new file mode 100644
index 00000000..4f8ad57d
--- /dev/null
+++ b/libraries/MS5837/keywords.txt
@@ -0,0 +1,29 @@
+# Syntax Colouring Map For MS5837
+
+# Data types (KEYWORD1)
+MS5837	KEYWORD1
+
+# Methods and Functions (KEYWORD2)
+begin	KEYWORD2
+isConnected	KEYWORD2
+reset	KEYWORD2
+getType	KEYWORD2
+getAddress	KEYWORD2
+
+read	KEYWORD2
+getPressure	KEYWORD2
+getTemperature	KEYWORD2
+getAltitude	KEYWORD2
+
+setDensity	KEYWORD2
+getDensity	KEYWORD2
+getDepth	KEYWORD2
+
+
+# Constants (LITERAL1)
+MS5837_LIB_VERSION	LITERAL1
+
+MS5837_TYPE_UNKNOWN	LITERAL1
+MS5837_TYPE_02	LITERAL1
+MS5837_TYPE_30	LITERAL1
+
diff --git a/libraries/MS5837/library.json b/libraries/MS5837/library.json
new file mode 100644
index 00000000..a01f65d3
--- /dev/null
+++ b/libraries/MS5837/library.json
@@ -0,0 +1,23 @@
+{
+  "name": "MS5837",
+  "keywords": "MS5837, temperature, pressure",
+  "description": "Arduino library for MS5837 temperature and pressure sensor.",
+  "authors":
+  [
+    {
+      "name": "Rob Tillaart",
+      "email": "Rob.Tillaart@gmail.com",
+      "maintainer": true
+    }
+  ],
+  "repository":
+  {
+    "type": "git",
+    "url": "https://github.com/RobTillaart/MS5837.git"
+  },
+  "version": "0.1.0",
+  "license": "MIT",
+  "frameworks": "*",
+  "platforms": "*",
+  "headers": "MS5837.h"
+}
diff --git a/libraries/MS5837/library.properties b/libraries/MS5837/library.properties
new file mode 100644
index 00000000..083fd136
--- /dev/null
+++ b/libraries/MS5837/library.properties
@@ -0,0 +1,11 @@
+name=MS5837
+version=0.1.0
+author=Rob Tillaart <rob.tillaart@gmail.com>
+maintainer=Rob Tillaart <rob.tillaart@gmail.com>
+sentence=Arduino library for MS5837 temperature and pressure sensor.
+paragraph=
+category=Signal Input/Output
+url=https://github.com/RobTillaart/MS5837
+architectures=*
+includes=MS5837.h
+depends=
diff --git a/libraries/MS5837/test/unit_test_001.cpp b/libraries/MS5837/test/unit_test_001.cpp
new file mode 100644
index 00000000..1d7e8bdd
--- /dev/null
+++ b/libraries/MS5837/test/unit_test_001.cpp
@@ -0,0 +1,51 @@
+//
+//    FILE: unit_test_001.cpp
+//  AUTHOR: Rob Tillaart
+//    DATE: 2020-12-06
+// PURPOSE: unit tests for the MS5837 current sensor
+//          https://github.com/RobTillaart/MS5837
+//          https://github.com/Arduino-CI/arduino_ci/blob/master/REFERENCE.md
+//
+
+// supported assertions
+// ----------------------------
+// assertEqual(expected, actual)
+// assertNotEqual(expected, actual)
+// assertLess(expected, actual)
+// assertMore(expected, actual)
+// assertLessOrEqual(expected, actual)
+// assertMoreOrEqual(expected, actual)
+// assertTrue(actual)
+// assertFalse(actual)
+// assertNull(actual)
+
+
+#include <ArduinoUnitTests.h>
+
+#include "Arduino.h"
+#include "MS5837.h"
+
+#define A0      0
+
+
+unittest_setup()
+{
+    fprintf(stderr, "MS5837_LIB_VERSION: %s\n", (char *) MS5837_LIB_VERSION);
+}
+
+unittest_teardown()
+{
+}
+
+
+unittest(test_constants)
+{
+  assertEqual(1,1);
+}
+
+
+
+unittest_main()
+
+
+//  -- END OF FILE --