Data transfer stops when I wrap my hand around the developer board.

Projects Programming
1

Hi,

I use a Bosch BMI160 sensor to measure the three-axis acceleration and orientation. This sensor is connected to a developer board. I read a total of 12 registers and expect 12 values ​​each time (one LSB and MSB value per axis).

Here is how it looks like: DevBoard with Sensor

  Wire.beginTransmission(AddrBMI160);
  Wire.write(12);
  Wire.endTransmission(true);
  Wire.requestFrom(AddrBMI160, 12, true);

  for (int i = 0; i < 12; i++) {

   Serial.print(Wire.read());

    if (i < 11) {
      Serial.print(",");
    }
  }

  Serial.println();
  delay(300);

My output looks like this:

"202,255,1,0,228,255,213,2,87,7,213,62"
"196,255,7,0,243,255,207,2,84,7,201,62"
//and so on...

If I put the developer board in my hand and close my hand for a short moment, then the "-1" is suddenly transferred 12 times and then the data transfer stops. However, the connection to the developer board is still available (the corresponding LED lights up). It happens every time I put my hand around the sensor as if my hand were an obstacle. How can it be that this happens? What might this -1 be?

"202,255,1,0,228,255,213,2,87,7,213,62"
"196,255,7,0,243,255,207,2,84,7,201,62"
"-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1"
// then data transfer stopps
2

If I put the developer board in my hand and close my hand for a short moment, then the "-1" is suddenly transferred 12 times and then the data transfer stops. However, the connection to the developer board is still available (the corresponding LED lights up). It happens every time I put my hand around the sensor as if my hand were an obstacle. How can it be that this happens? What might this -1 be?

Most probably a broken wire.
-1 means connection to sensor by I2C failed.

3

Sounds like a dodgy connection.

Does the same thing happen when your hand is wearing a thick non-conductive glove ?

4

srnet:
Sounds like a dodgy connection.

Does the same thing happen when your hand is wearing a thick non-conductive glove ?

Hello, I don't have a thick glove, but I wrapped the developer board with a rubber sports band and the data transfer was not interrupted. Strange..