I noticed the VARIANT_MCK in https://github.com/DFRobot/STM32/blob/master/cores/blunoM3/wiring.h line 68 and I don't know what is it. Thanks lot in advance!

The usage of Wire.requestFrom() is not correct in the files:

• STM32/libraries/DFRobotBlunoM3/ADXL345/ADXL345.ino
• STM32/libraries/DFRobotBlunoM3/Sample_10Dof/BMP085.ino
• STM32/libraries/Sample_10Dof/FreeSixIMU/FIMU_ADXL345.cpp
• STM32/libraries/Sample_10Dof/FreeSixIMU/FIMU_ITG3200.cpp
• STM32/libraries/Sample_10Dof/HMC5883L/HMC5883L.cpp
• STM32/libraries/HMC5883L/hmc5883l.cpp
• STM32/libraries/FreeSixIMU/FIMU_ITG3200.cpp
• STM32/libraries/FreeSixIMU/FIMU_ADXL345.cpp

The Wire.requestFrom() should not be encapsulated by Wire.beginTransmission() and Wire.endTransmission() and no waiting is needed.

Explanation: Common-mistakes number 1, 2, and 3.

For example this code:

  Wire.beginTransmission(device); //start transmission to device
  Wire.requestFrom(device, num);    // request 6 bytes from device
  
  int i = 0;
  while(Wire.available())    //device may send less than requested (abnormal)
  { 
    buff[i] = Wire.read(); // receive a byte
    delay(30);
    i++;
  }
  Wire.endTransmission(); //end transmission

could be like this:

  Wire.requestFrom(device, num);    // request 6 bytes from device
  if(Wire.available() == num)
  {
    for(int i=0; i<num; i++)
    {
      buf[i] = Wire.read();   // read a byte from the Wire buffer
    }
  }

I am trying to read I2C data using STM32F103C as a master with Wire library. I need to made continuous readings without sending STOP bit between readings so I am using Wire.requestFrom(Address,size,false) and then Wire.read() functions. When I compile my project in Ardunino 1.8.9 environment I get the error:
no matching function for call to 'TwoWire::requestFrom(const int&, int&, int)

The project is compiled without errors when only 2 parameters are used with Wire.requestFrom(Address,size) function. However I need to avoid sending STOP bit after the read operation is completed. How can this done in my case?