fix isConnected() for NANO 33 BLE (#20)

MS5611.cpp

@@ -2,11 +2,12 @@
 //    FILE: MS5611.cpp
 //  AUTHOR: Rob Tillaart
 //          Erni - testing/fixes
-// VERSION: 0.3.4
+// VERSION: 0.3.5
 // PURPOSE: MS5611 Temperature & Humidity library for Arduino
 //     URL: https://github.com/RobTillaart/MS5611
 //
 //  HISTORY:
+//  0.3.5   2022-01-13  fix isConnected() for NANO 33 BLE
 //  0.3.4   2021-12-29  fix #16 compilation for MBED
 //  0.3.3   2021-12-25  Update oversampling timings to reduce time spent waiting
 //  0.3.2   2021-12-24  add get/set oversampling, read() (thanks to LyricPants66133)
@@ -18,7 +19,7 @@
 //
 //  0.2.2   2021-01-01  add Arduino-CI + unit tests + isConnected()
 //  0.2.1   2020-06-28  fix #1 min macro compile error
-//  0.2.0   2020-06-21  refactor; #pragma once; 
+//  0.2.0   2020-06-21  refactor; #pragma once;
 //
 //  0.1.8               fix #109 incorrect constants (thanks to flauth)
 //  0.1.7               revert double to float (issue 33)
@@ -104,6 +105,7 @@ bool MS5611::begin(TwoWire * wire)
 bool MS5611::isConnected()
 {
   _wire->beginTransmission(_address);
+  _wire->write(0);                        // needed for NANO 33 BLE
   return (_wire->endTransmission() == 0);
 }
 
@@ -147,7 +149,7 @@ int MS5611::read(uint8_t bits)
   if (_result) return _result;
   uint32_t _D2 = readADC();
   if (_result) return _result;
-  
+
   //  TEST VALUES - comment lines above
   // uint32_t D1 = 9085466;
   // uint32_t D2 = 8569150;

MS5611.h

@@ -3,16 +3,33 @@
 //    FILE: MS5611.h
 //  AUTHOR: Rob Tillaart
 //          Erni - testing/fixes
-// VERSION: 0.3.4
+// VERSION: 0.3.5
 // PURPOSE: Arduino library for MS5611 temperature and pressure sensor
 //     URL: https://github.com/RobTillaart/MS5611
 
 
 #include "Arduino.h"
 #include "Wire.h"
 
+//  BREAKOUT  MS5611  aka  GY63 - see datasheet
+//
+//  SPI    I2C
+//              +--------+
+//  VCC    VCC  | o      |
+//  GND    GND  | o      |
+//         SCL  | o      |
+//  SDI    SDA  | o      |
+//  CSO         | o      |
+//  SDO         | o L    |   L = led
+//          PS  | o    O |   O = opening  PS
+//              +--------+
+//
+//  PS to VCC  ==>  I2C
+//  PS to GND  ==>  SPI
+//  CS to VCC  ==>  0x76
+//  CS to GND  ==>  0x77
 
-#define MS5611_LIB_VERSION                    (F("0.3.4"))
+#define MS5611_LIB_VERSION                    (F("0.3.5"))
 
 
 #define MS5611_READ_OK                        0

README.md

@@ -18,14 +18,47 @@ The high resolution is made possible by oversampling (many times).
 
 The device address is 0x76 or 0x77 depending on the CSB pin.
 
-
-#### 0.3.0 breaking changes
+This library only implements the I2C interface. 
+
+```cpp
+//
+//  BREAKOUT  MS5611  aka  GY63 - see datasheet
+//
+//  SPI    I2C
+//              +--------+
+//  VCC    VCC  | o      |
+//  GND    GND  | o      |
+//         SCL  | o      |
+//  SDI    SDA  | o      |
+//  CSO         | o      |
+//  SDO         | o L    |   L = led
+//          PS  | o    O |   O = opening  PS
+//              +--------+
+//
+//  PS to VCC  ==>  I2C
+//  PS to GND  ==>  SPI
+//  CS to VCC  ==>  0x76
+//  CS to GND  ==>  0x77
+//
+```
+
+## important Changes
+
+#### 0.3.0 breaking change
 
 1. fixed math error so previous versions are **obsolete**.
 2. temperature is a float expressed in degrees Celsius.
 3. pressure is a float expressed in mBar.
 
 
+#### 0.3.5 NANO 33 BLE
+
+After lots of hours of testing it appeared that the I2C/Wire library of the NANO 33 BLE
+does not handle **isConnected()** like other platforms do. 
+It looks like an uninitialized length of the I2C buffer, causing failure when calling **begin()**.
+Adding a **wire->write(0x00)** seems to fix the issue.
+
+
 ## Interface
 
 - **MS5611(uint8_t deviceAddress)** constructor.
@@ -34,18 +67,20 @@ The device address is 0x76 or 0x77 depending on the CSB pin.
 - **bool isConnected()** checks availability of device address on the I2C bus.
 - **reset()** resets the chip and loads constants from its ROM.
 - **int read(uint8_t bits)** the actual reading of the sensor. Returns MS5611_READ_OK upon success.
-- **int read()** the actual reading of the sensor. Returns MS5611_READ_OK upon success.
+- **int read()** the actual reading of the sensor, uses the preset oversampling (see below). Returns MS5611_READ_OK upon success.
 - **void setOversampling(osr_t samplingRate)** sets the amount of oversampling. 
 See table below and test example how to use.
 - **osr_t getOversampling()** returns amount of oversampling.
 - **float getTemperature()** returns temperature in °C. Subsequent calls will return same value until a new **read()** is called.
 - **float getPressure()** pressure is in mBar. Subsequent calls will return same value until a new **read()** is called.
 - **int getLastResult()** checks last I2C communication (replace with more informative error handling?)
-- **uint32_t lastRead()** last time when **read()** was called in millis() since startup.
+- **uint32_t lastRead()** last time when **read()** was called in milliseconds since startup.
 
 
 #### Oversampling table
 
+(numbers from datasheet, actual time differs - todo)
+
 | definition     | value | oversampling ratio | resolution (mbar) | time (ms) | notes |
 |:--------------:|:-----:|:------------------:|:----------------:|:---------:|:------:|
 | OSR_ULTRA_HIGH |  12   |        4096        |      0.012       |   8.22    |
@@ -57,8 +92,7 @@ See table below and test example how to use.
 
 ## Disclaimer
 
-The library is experimental. As I have no such sensor the quality is hard to test.
-So if you happen to have such a sensor, please give it a try and let me know.
+The library is still experimental. So all feedback is welcome.
 
 
 ## Operation
@@ -68,11 +102,12 @@ See examples
 
 ## Future
 
-- get such a sensor to test
 - update documentation
 - create a SPI based library (same base class if possible?)
+  - first get it working 100%
 - proper error handling
 - redo lower level functions?
-- handle the read + math of temperature first? (need hardware to test)
--
+- handle the read + math of temperature first? 
+- add get- and setPressureOffset()
+- add get- and setTemperatureOffset()
 

examples/MS5611_detector/MS5611_detector.ino

@@ -0,0 +1,44 @@
+//
+//    FILE: MS5611_DETECTOR.ino
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+// PURPOSE: detect an MS5611 on a NANO33 BLE
+//    DATE: 2022-01-13
+//     URL: https://github.com/RobTillaart/MS5611
+
+
+#include "Arduino.h"
+#include "Wire.h"
+
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+
+  Wire.begin();
+  Wire.beginTransmission(0x76);
+  Wire.write(0);
+  int x = Wire.endTransmission();
+  Wire.beginTransmission(0x77);
+  Wire.write(0);
+  int y = Wire.endTransmission();
+
+  Serial.println(x);
+  Serial.println(y);
+  delay(1000);
+
+  if (x == 0) Serial.println("MS5611 found at 0x76");
+  else if (y == 0) Serial.println("MS5611 found at 0x77");
+  else Serial.println("no MS5611 found");
+
+  Serial.println("done...");
+}
+
+
+void loop()
+{
+}
+
+
+// -- END OF FILE --

examples/MS5611_minimal/MS5611_minimal.ino

@@ -14,7 +14,10 @@ MS5611 MS5611(0x77);   // 0x76 = CSB to VCC; 0x77 = CSB to GND
 void setup()
 {
   Serial.begin(115200);
-  Serial.print(__FILE__);
+  while(!Serial);
+
+  Serial.println();
+  Serial.println(__FILE__);
   Serial.print("MS5611_LIB_VERSION: ");
   Serial.println(MS5611_LIB_VERSION);
 
@@ -25,18 +28,20 @@ void setup()
   else
   {
     Serial.println("MS5611 not found. halt.");
-    while(1);
+    while (1);
   }
+  Serial.println();
 }
 
 
 void loop()
 {
   MS5611.read();           // note no error checking => "optimistic".
-  Serial.print("\nT:\t");
+  Serial.print("T:\t");
   Serial.print(MS5611.getTemperature(), 2);
   Serial.print("\tP:\t");
   Serial.print(MS5611.getPressure(), 2);
+  Serial.println();
   delay(1000);
 }
 

examples/MS5611_performance/MS5611_performance.ino

@@ -9,7 +9,7 @@
 #include "MS5611.h"
 
 
-MS5611 MS5611(0x77);   // 0x76 = CSB to VCC; 0x77 = CSB to GND
+MS5611 MS5611(0x76);   // 0x76 = CSB to VCC; 0x77 = CSB to GND
 
 
 uint32_t start, stop, count;
@@ -18,19 +18,23 @@ uint32_t start, stop, count;
 void setup()
 {
   Serial.begin(115200);
-  Serial.print(__FILE__);
-  Serial.print("MS5611 lib version: ");
+  while(!Serial);
+
+  Serial.println();
+  Serial.println(__FILE__);
+  Serial.print("MS5611_LIB_VERSION: ");
   Serial.println(MS5611_LIB_VERSION);
 
-  if (MS5611.begin())
+  if (MS5611.begin() == true)
   {
     Serial.println("MS5611 found.");
   }
   else
   {
     Serial.println("MS5611 not found. halt.");
-    while(1);
+    while (1);
   }
+  Serial.println();
 
   count = 0;
 }

examples/MS5611_performance_all/MS5611_performance_all.ino

@@ -16,19 +16,23 @@ uint32_t start, stop;
 void setup()
 {
   Serial.begin(115200);
-  Serial.print(__FILE__);
-  Serial.print("MS5611 lib version: ");
+  while(!Serial);
+
+  Serial.println();
+  Serial.println(__FILE__);
+  Serial.print("MS5611_LIB_VERSION: ");
   Serial.println(MS5611_LIB_VERSION);
 
-  if (MS5611.begin())
+  if (MS5611.begin() == true)
   {
     Serial.println("MS5611 found.");
   }
   else
   {
     Serial.println("MS5611 not found. halt.");
-    while(1);
+    while (1);
   }
+  Serial.println();
 
   Serial.println("OSR \t TIME");