Interfacing with BNO055 over I2C

I'm trying to interface with a BNO055 absolute orientation sensor. I'm new to both I2C and Lua, but I've tried to combine the Lua examples for reading from similar sensors and this python code from Adafruit which lists the addresses of the various sensors and protocol for setting modes. However, I'm getting zeroes when I try to read from the device. Any suggestions for where I'm going wrong?

function convert_16_bit(lsb,msb)
  res = 0
  if msb >= 128 then
    res = (-0x7FFF+((msb-128)*256+lsb))
  else
    res = (msb*256+lsb)
  end
  return res
end

boardAddr = 0x28 -- address of the board (as found by https://labjack.com/support/software/examples/lua-scripting/i2c/i2c-tuto...)

--SDA is connected to EIO0
sdaPin = 8

--SCL is connected to EIO1
sclPin = 9

--pin num map: FIO0:7 = 0:7, EIO0:7 = 8:15, CIO0:7 = 16:23

throttleVal = 0 --0=fastest; 65535=fastest; 65534, 65533, etc. gets slower.

I2C.config(sdaPin, sclPin, throttleVal, 0, boardAddr, 0) --configure the I2C Bus

--init board slave
MB.W(5104, 0, boardAddr)--change target to board

-- Set to normal power mode.
BNO055_PWR_MODE_ADDR = 0x3E
POWER_MODE_NORMAL = 0x00
I2C.write({BNO055_PWR_MODE_ADDR, POWER_MODE_NORMAL})

-- Enable ndof mode
BNO055_OPR_MODE_ADDR = 0x3D
OPERATION_MODE_NDOF = 0x0C
I2C.write({BNO055_OPR_MODE_ADDR, OPERATION_MODE_NDOF})

-- Quaternion data registers
BNO055_QUATERNION_DATA_W_LSB_ADDR    = 0x20
BNO055_QUATERNION_DATA_W_MSB_ADDR    = 0x21
BNO055_QUATERNION_DATA_x_LSB_ADDR    = 0x22
BNO055_QUATERNION_DATA_x_MSB_ADDR    = 0x23
BNO055_QUATERNION_DATA_Y_LSB_ADDR    = 0x24
BNO055_QUATERNION_DATA_Y_MSB_ADDR    = 0x25
BNO055_QUATERNION_DATA_Z_LSB_ADDR    = 0x26
BNO055_QUATERNION_DATA_Z_MSB_ADDR    = 0x27

--Begin loop
LJ.IntervalConfig(0, 100)
while true do
  if LJ.CheckInterval(0) then

    -- loop over data registers
    dataQuatRaw = {}
    for i=0, 7 do
      I2C.write({BNO055_QUATERNION_DATA_W_LSB_ADDR+i}) -- points to the desired address
      dataIn = I2C.read(1)  -- reads from that address
      table.insert(dataQuatRaw, dataIn[1])
    end
    dataQuat = {}

    -- convert from lsb/msb to values
    table.insert(dataQuat, convert_16_bit(dataQuatRaw[1], dataQuatRaw[2]))
    table.insert(dataQuat, convert_16_bit(dataQuatRaw[3], dataQuatRaw[4]))
    table.insert(dataQuat, convert_16_bit(dataQuatRaw[5], dataQuatRaw[6]))
    table.insert(dataQuat, convert_16_bit(dataQuatRaw[7], dataQuatRaw[8]))

    -- this always prints zeroes for some reason
    print("W: "..dataQuat[1].."X: "..dataQuat[2].."Y: "..dataQuat[3].."Z: "..dataQuat[4])

    --Report results to print() and User RAM--
    --MB.W(46000, 3, dataQuat[1])
    --MB.W(46002, 3, dataQuat[2])
    --MB.W(46004, 3, dataQuat[3])
    --MB.W(46006, 3, dataQuat[4])
  end
end
print("Done.")
MB.W(6000, 1, 0)