Everything needs to be soldered together...In a way...
NOTE: The 3 axis sensor is an expensive little thing double check the wiring before powering the all thing up...
See the schematics attached for all the wiring used in this project.
The attached source code can only work if you use the same pin numbers I did, but feel free to change those when connecting as long as you change the appropriate numbers in the code.
Connecting the 3 axis sensor to the logic level converter: Sensor VCC -> Arduino 3V3 Sensor GND -> Arduino Gnd Sensor SDA -> Converter TXI (Chan1) Converter TXO (Chan1) -> Arduino ANALOG IN 4 Sensor SCL -> Converter TXI (Chan2) Converter TXO (Chan2) -> Arduino ANALOG IN 5 Converter GND (at least one of them) -> Arduino Gnd Converter HV -> Arduino 5V Converter LV -> Arduino 3V3
Optical sensor to Arduino: See attached image Digital in = Pin 11 on the Arduino
LED: GND to some GND (I used one of the optical sensor) + to Arduino PIN 13 (This was done since this pin already have an on-board resistor, if you use a different one, make sure to use a resistor so you wont burn the LED)