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P a g e
Sensor Calculations
The IMU data (accelerometer, magnetometer, and gyroscope) and RGB light sensor data are stored as 16-bit
integers. They need to be multiplied by a calibration factor to get appropriate units.
The pressure data are stored as mBar and a depth calculation is performed assuming saltwater (111.377
mBar/m) and a surface pressure of 1010.0 mBar.
The temperature data are stored as degrees Celsius.
Spin is the number of rotations of the impeller per second.
V is battery voltage.
Date is the date and time from the real-time clock and assumes the time was set to UTC.
Sensor Calibration Factors: Multiply the sensor values by these values
Sensor
Calibration Factor
Units
Accelerometer
16 g / 32768 = 0.00048828
g
Magnetometer
4800 uT / 32768 = 0.146484375
microTesla
Gyroscope
1000 deg/s / 32768 = 0.0030517578
Degrees / second
Red
20 uW/cm
2
/ 65536 = 0.003051758
microWatt/cm
2
Green
18 uW/cm
2
/ 65536 = 0.000274658
microWatt/cm
2
Blue
30 uW/cm
2
/ 65536 = 0.000457764
microWatt/cm
2
