Cannot communicate with MS5611 in GY-86 with Due

Other Hardware Sensors
1

I am using GY-86 which is a breakout board for MPU6050, HMC5883L and MS5611. The MS5611 is a barometer.

I used GY-86 with Arduino Uno and successfully used all three sensors, but when I try to use the same code on Arduino Due, MS5611 won't respond. The other sensors read perfectly.

I'm not sure if this is a hardware problem or a problem in the code.

I've attached the library I am using in my code, and the example code (provided with the library) is:

#include <Wire.h>
#include <MS5611.h>

MS5611 ms5611;

double referencePressure;

void setup() 
{
  Serial.begin(9600);

  // Initialize MS5611 sensor
  Serial.println("Initialize MS5611 Sensor");

  while(!ms5611.begin())
  {
    Serial.println("Could not find a valid MS5611 sensor, check wiring!");
    delay(500);
  }

  // Get reference pressure for relative altitude
  referencePressure = ms5611.readPressure();

  // Check settings
  checkSettings();
}

void checkSettings()
{
  Serial.print("Oversampling: ");
  Serial.println(ms5611.getOversampling());
}

void loop()
{
  // Read raw values
  uint32_t rawTemp = ms5611.readRawTemperature();
  uint32_t rawPressure = ms5611.readRawPressure();

  // Read true temperature & Pressure
  double realTemperature = ms5611.readTemperature();
  long realPressure = ms5611.readPressure();

  // Calculate altitude
  float absoluteAltitude = ms5611.getAltitude(realPressure);
  float relativeAltitude = ms5611.getAltitude(realPressure, referencePressure);

  Serial.println("--");

  Serial.print(" rawTemp = ");
  Serial.print(rawTemp);
  Serial.print(", realTemp = ");
  Serial.print(realTemperature);
  Serial.println(" *C");

  Serial.print(" rawPressure = ");
  Serial.print(rawPressure);
  Serial.print(", realPressure = ");
  Serial.print(realPressure);
  Serial.println(" Pa");

  Serial.print(" absoluteAltitude = ");
  Serial.print(absoluteAltitude);
  Serial.print(" m, relativeAltitude = ");
  Serial.print(relativeAltitude);    
  Serial.println(" m");

  delay(1000);
}

The schematic for the GY-86 looks like this:

I wired 3.3v from the due to GY-86's 3.3v, and the 5v pin is not connected. The GY-86 has a level shifter from 3.3v to 5v from the sensors' SCL, SDA to breakout pins H_SCL and H_SDA, so I guessed wiring 5v to the GY-86 would damage the Due.

I read somewhere that there are internal pull up resistors in the due's SCL and SDA of 1.5k, so maybe the level shifter in the GY-86 is reducing the total resistance too much, and that's causing the problem?

MS5611.cpp (5.42 KB)

MS5611.h (1.95 KB)

2

Well, this is awkward...

I've been searching for the solution for days with no avail, but as soon as I posted this I found the solution.
The library code is wrong.

When using due, one shouldn't use

Wire.endTransmission();

after

Wire.requestFrom();

3

hsezekielpark:
I am using GY-86 which is a breakout board for MPU6050, HMC5883L and MS5611. The MS5611 is a barometer.

I used GY-86 with Arduino Uno and successfully used all three sensors, but when I try to use the same code on Arduino Due, MS5611 won't respond. The other sensors read perfectly.

I'm not sure if this is a hardware problem or a problem in the code.

I've attached the library I am using in my code, and the example code (provided with the library) is:

#include <Wire.h>

#include <MS5611.h>

MS5611 ms5611;

double referencePressure;

void setup()
{
 Serial.begin(9600);

// Initialize MS5611 sensor
 Serial.println("Initialize MS5611 Sensor");

while(!ms5611.begin())
 {
   Serial.println("Could not find a valid MS5611 sensor, check wiring!");
   delay(500);
 }

// Get reference pressure for relative altitude
 referencePressure = ms5611.readPressure();

// Check settings
 checkSettings();
}

void checkSettings()
{
 Serial.print("Oversampling: ");
 Serial.println(ms5611.getOversampling());
}

void loop()
{
 // Read raw values
 uint32_t rawTemp = ms5611.readRawTemperature();
 uint32_t rawPressure = ms5611.readRawPressure();

// Read true temperature & Pressure
 double realTemperature = ms5611.readTemperature();
 long realPressure = ms5611.readPressure();

// Calculate altitude
 float absoluteAltitude = ms5611.getAltitude(realPressure);
 float relativeAltitude = ms5611.getAltitude(realPressure, referencePressure);

Serial.println("--");

Serial.print(" rawTemp = ");
 Serial.print(rawTemp);
 Serial.print(", realTemp = ");
 Serial.print(realTemperature);
 Serial.println(" *C");

Serial.print(" rawPressure = ");
 Serial.print(rawPressure);
 Serial.print(", realPressure = ");
 Serial.print(realPressure);
 Serial.println(" Pa");

Serial.print(" absoluteAltitude = ");
 Serial.print(absoluteAltitude);
 Serial.print(" m, relativeAltitude = ");
 Serial.print(relativeAltitude);    
 Serial.println(" m");

delay(1000);
}




The schematic for the GY-86 looks like this:

![|500x461](http://www.thaieasyelec.com/downloads/ESEN246/GY-86_SCH.jpg)


I wired 3.3v from the due to GY-86's 3.3v, and the 5v pin is not connected. The GY-86 has a level shifter from 3.3v to 5v from the sensors' SCL, SDA to breakout pins H_SCL and H_SDA, so I guessed wiring 5v to the GY-86 would damage the Due.


I read somewhere that there are internal pull up resistors in the due's SCL and SDA of 1.5k, so maybe the level shifter in the GY-86 is reducing the total resistance too much, and that's causing the problem?

try connecting both the 3.3 and VCC (5V) to the 3.3V supply
the level shifter should do nothing but pass the signals across at the 3.3V level
Z

4

I tried using the MS5611 several times, and never got it to work, so I went back to using my BMP180.

It is fussy about something with I2C, I am not quite sure what.

5

I'm still trying.....