0.4.0 MS5611_SPI

Author: RobTillaart

libraries/MS5611_SPI/.github/workflows/arduino-lint.yml

@@ -6,8 +6,8 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v4
-      - uses: arduino/arduino-lint-action@v1
+      - uses: actions/checkout@v5
+      - uses: arduino/arduino-lint-action@v2
         with:
           library-manager: update
           compliance: strict

libraries/MS5611_SPI/.github/workflows/arduino_test_runner.yml

@@ -8,7 +8,7 @@ jobs:
     timeout-minutes: 20
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: 2.6

libraries/MS5611_SPI/.github/workflows/jsoncheck.yml

@@ -5,13 +5,15 @@ on:
     paths:
       - '**.json'
   pull_request:
+    paths:
+      - '**.json'
 
 jobs:
   test:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - name: json-syntax-check
         uses: limitusus/json-syntax-check@v2
         with:

libraries/MS5611_SPI/CHANGELOG.md

@@ -6,6 +6,15 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
+## [0.4.0] - 2025-09-26
+- fix #14, sync MS5611
+- add **getAltitudeFeet(float airPressure)**
+- moved code to .cpp
+- update keywords.txt
+- minor edits
+
+----
+
 ## [0.3.1] - 2024-06-03
 - add support for ARDUINO_ARCH_MBED
 

libraries/MS5611_SPI/LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2014-2024 Rob Tillaart
+Copyright (c) 2014-2025 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

libraries/MS5611_SPI/MS5611_SPI.cpp

@@ -1,11 +1,9 @@
 //
 //    FILE: MS5611_SPI.cpp
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.3.1
-// PURPOSE: MS5611 (SPI) Temperature & Pressure library for Arduino
+// VERSION: 0.4.0
+// PURPOSE: Arduino library for MS5611 (SPI) temperature and pressure sensor
 //     URL: https://github.com/RobTillaart/MS5611_SPI
-//
-//  HISTORY: see changelog.md
 
 
 #include "MS5611_SPI.h"
@@ -96,7 +94,7 @@ bool MS5611_SPI::begin()
     digitalWrite(_clock,   LOW);
   }
 
-  return reset();
+  return reset(0);  //  MS5611 has mathMode 0, see datasheet + initConstants.
 }
 
 
@@ -111,8 +109,9 @@ bool MS5611_SPI::reset(uint8_t mathMode)
 {
   command(MS5611_CMD_RESET);
   uint32_t start = micros();
+
   //  while loop prevents blocking RTOS
-  while (micros() - start < 3000)     //  increased as first ROM values were missed.
+  while (micros() - start < 3000)  //  increased as first ROM values were missed.
   {
     yield();
     delayMicroseconds(10);
@@ -130,7 +129,7 @@ bool MS5611_SPI::reset(uint8_t mathMode)
     //  C[7] == CRC - skipped.
     uint16_t tmp = readProm(reg);
     C[reg] *= tmp;
-    //  _deviceID is a simple SHIFT XOR merge of PROM data
+    //  _deviceID is a SHIFT XOR merge of 7 PROM registers, reasonable unique
     _deviceID <<= 4;
     _deviceID ^= tmp;
     //  Serial.println(readProm(reg));
@@ -147,16 +146,22 @@ int MS5611_SPI::read(uint8_t bits)
 {
   //  VARIABLES NAMES BASED ON DATASHEET
   //  ALL MAGIC NUMBERS ARE FROM DATASHEET
+
   convert(MS5611_CMD_CONVERT_D1, bits);
+  if (_result) return _result;
   //  NOTE: D1 and D2 seem reserved in MBED (NANO BLE)
   uint32_t _D1 = readADC();
+  if (_result) return _result;
+
   convert(MS5611_CMD_CONVERT_D2, bits);
+  if (_result) return _result;
   uint32_t _D2 = readADC();
+  if (_result) return _result;
 
   //  Serial.println(_D1);
   //  Serial.println(_D2);
 
-  //   TEST VALUES - comment lines above
+  //  TEST VALUES - comment lines above
   //  uint32_t _D1 = 9085466;
   //  uint32_t _D2 = 8569150;
 
@@ -218,13 +223,21 @@ float MS5611_SPI::getTemperature() const
 }
 
 
+//  milliBar
 float MS5611_SPI::getPressure() const
 {
   if (_pressureOffset == 0) return _pressure * 0.01;
   return _pressure * 0.01 + _pressureOffset;
 }
 
 
+//  Pascal SI-unit.
+float MS5611_SPI::getPressurePascal() const
+{
+  if (_pressureOffset == 0) return _pressure;
+  return _pressure + _pressureOffset * 100.0;
+}
+
 void MS5611_SPI::setPressureOffset(float offset)
 {
   _pressureOffset = offset;
@@ -249,6 +262,25 @@ float MS5611_SPI::getTemperatureOffset()
 }
 
 
+//  (from MS5837)
+//  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 (stale link).
+//  https://en.wikipedia.org/wiki/Pressure_altitude
+float MS5611_SPI::getAltitude(float airPressure)
+{
+  //  _pressure is in Pascal (#44) and airPressure in mBar.
+  float ratio = _pressure * 0.01 / airPressure;
+  return 44307.694 * (1 - pow(ratio, 0.190284));
+}
+
+
+float MS5611_SPI::getAltitudeFeet(float airPressure)
+{
+  float ratio = _pressure * 0.01 / airPressure;
+  return 145366.45 * (1 - pow(ratio, 0.190284));
+}
+
+
 int MS5611_SPI::getLastResult() const
 {
   return _result;
@@ -291,6 +323,18 @@ uint16_t MS5611_SPI::getSerialCode()
   return readProm(7) >> 4;
 }
 
+//       DEVELOP
+uint16_t MS5611_SPI::getProm(uint8_t index)
+{
+  return readProm(index);
+}
+
+//       DEVELOP
+uint16_t MS5611_SPI::getCRC()
+{
+  return readProm(7) & 0x0F;
+}
+
 
 void MS5611_SPI::setSPIspeed(uint32_t speed)
 {
@@ -311,23 +355,22 @@ bool MS5611_SPI::usesHWSPI()
 }
 
 
-
 /////////////////////////////////////////////////////
 //
-//  PRIVATE
+//  PROTECTED
 //
 void MS5611_SPI::convert(const uint8_t addr, uint8_t bits)
 {
-  //  values from page 3 datasheet - MAX column (rounded up)
-  uint16_t del[5] = {600, 1200, 2300, 4600, 9100};
-
   uint8_t index = bits;
   if (index < 8) index = 8;
   else if (index > 12) index = 12;
   index -= 8;
   uint8_t offset = index * 2;
   command(addr + offset);
 
+  //  values from page 3 datasheet - MAX column (rounded up)
+  uint16_t del[5] = {600, 1200, 2300, 4600, 9100};
+
   uint16_t waitTime = del[index];
   uint32_t start = micros();
   //  while loop prevents blocking RTOS
@@ -467,5 +510,12 @@ void MS5611_SPI::initConstants(uint8_t mathMode)
 }
 
 
+///////////////////////////////////////////////////////////////////
+//
+//  DERIVED CLASSES
+//
+//  TODO ?
+
+
 //  -- END OF FILE --
 

libraries/MS5611_SPI/MS5611_SPI.h

@@ -2,8 +2,8 @@
 //
 //    FILE: MS5611_SPI.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.3.1
-// PURPOSE: S5611 (SPI) Temperature & Pressure library for Arduino
+// VERSION: 0.4.0
+// PURPOSE: Arduino library for MS5611 (SPI) temperature and pressure sensor
 //     URL: https://github.com/RobTillaart/MS5611_SPI
 
 
@@ -30,7 +30,7 @@
 //  CS to GND  ==>  0x77
 
 
-#define MS5611_SPI_LIB_VERSION                (F("0.3.1 EXPERIMENTAL"))
+#define MS5611_SPI_LIB_VERSION                (F("0.4.0 EXPERIMENTAL"))
 
 #ifndef __SPI_CLASS__
   //  MBED must be tested before RP2040
@@ -72,7 +72,7 @@ class MS5611_SPI
 
   //       reset command + get constants
   //       mathMode = 0 (default), 1 = factor 2 fix.
-  //       returns false if ROM constants == 0;
+  //       returns false if ROM constants are 0;
   bool     reset(uint8_t mathMode = 0);
 
   //  the actual reading of the sensor;
@@ -87,40 +87,54 @@ class MS5611_SPI
   //  oversampling rate is in osr_t
   osr_t    getOversampling() const;
 
-  //  temperature is in ²C
+  //  temperature is in degrees C
   float    getTemperature() const;
-
   //  pressure is in mBar
   float    getPressure() const;
+  //  pressure is in Pascal (SI-unit)
+  float    getPressurePascal() const;
 
   //  OFFSET
+  //  pressure offset is in mBar.
   void     setPressureOffset(float offset = 0);
   float    getPressureOffset();
+  //  temperature offset in degrees C.
   void     setTemperatureOffset(float offset = 0);
   float    getTemperatureOffset();
 
+  //  ALTITUDE (from MS5837)
+  //  air pressure in mBar, returns meters
+  float    getAltitude(float airPressure = 1013.25);
+  //  idem, returns feet.
+  float    getAltitudeFeet(float airPressure = 1013.25);
+
   //  to check for failure
   int      getLastResult() const;
 
   //  last time in millis() when the sensor has been read.
   uint32_t lastRead() const;
 
+  //  _deviceID is a SHIFT XOR merge of 7 PROM registers, reasonable unique
   uint32_t getDeviceID() const;
 
   void     setCompensation(bool flag = true);
   bool     getCompensation();
 
+  //       EXPERIMENTAL
+  uint16_t getManufacturer();
+  uint16_t getSerialCode();
+
+  //       DEVELOP
+  uint16_t getProm(uint8_t index);
+  uint16_t getCRC();
+
   //  develop functions.
   /*
   void     setAddress(uint8_t address) { _address = address; };  // RANGE CHECK
   uint8_t  getAddress() const          { return _address; };
   uint8_t  detectAddress() { todo };  // works with only one on the bus?
   */
 
-  //       EXPERIMENTAL
-  uint16_t getManufacturer();
-  uint16_t getSerialCode();
-
 
   //       speed in Hz
   void     setSPIspeed(uint32_t speed);
@@ -144,7 +158,7 @@ class MS5611_SPI
   float    _pressureOffset;
   float    _temperatureOffset;
   int      _result;
-  float    C[7];
+  float    C[7];   //  constants, name from datasheet
   uint32_t _lastRead;
   uint32_t _deviceID;
   bool     _compensation;
@@ -162,5 +176,13 @@ class MS5611_SPI
 };
 
 
+
+///////////////////////////////////////////////////////////////////
+//
+//  DERIVED CLASSES
+//
+//  class MS5607_SPI : public MS5611_SPI  ??
+
+
 //  -- END OF FILE --