We will attach the led lighting device in front of the ROV. Since the tube which the electric devices are inserted is elongated in the front and back direction, the lighting device cannot enter the tube. So I'm thinking of placing it on the outside of the tube. The shape of it will be similar to the OpenROV Light Cube.
Also, we plan to put the led driver inside the cube so that the brightness can easily be controlled by simply inputting pwm from the outside. Once, I design the PCB and leave it to production, I will be able to test it by next Monday.
And the source is available in github.