Communication and Control
The Arduino controller is a very commonly used robotics controller with a broad base of support, code, and add-ons available. The power requirement is 7 to 12 volts DC.
DIYDrones ArduIMU+ V3 $80
Adafruit 10-DOF IMU Breakout - L3GD20 + LSM303 + BMP180
Triple-axis Accelerometer+Magnetometer (Compass) - LSM303 $24.95
HMC5883L Digital Compass Module - Blue
A single twisted pair ( 2 conductors ) is provided from the surface vessel to the ROV. In order to make use of off-the-shelf Ethernet equipment a the connection will be used as a Very-high-bit-rate digital subscriber line or VDSL2 technology uses a bandwidth up to 30 MHz. It was developed to allow ordinary 24 awg telephone twisted pair wiring to be used for computer network communication from 10 to 50 Mbit/s at 3,300 ft (1 km).
Startech 10/100 VDSL Ethernet Extender Kit tested with Ixia QCheck using 100kByte samples consistently ran up to 43.7Mbps over 3000 ft of 1 pair 24 awg wire.
The problem with LAN switch not working and needing to use a HUB is that ARP messages are being blocked by the DSL unit this is Normal as the telco do not want your ARP messages being sent to the internet. The DSL unit will have a setup with it acting like a Gateway and then all you need to do is setup a route on you laptop to point to the DSL Gateway IP address for the IP address Range on the sub side.
The StarTeck VDSL kit
Other VDSL solutions:
VC-201A Planet 10/100 Ethernet Extender over RJ-11 $129
The single twisted pair umbilical will be provided by the vessel but cable need for testing will be a common burial Cat5 network cable with 4, 24 awg twisted pairs.
The cables below are not designed for high loads or deep sea environments. But they low cost, readily available, often discounted on ebay, and worthy of testing.
ebay: 24/4pr 24 gauge AWG 4 pair Cat 5E cable wire Essex 1143-H
direct burial 1000 ft $119.75 On-Order
Outdoor/Direct Burial Speaker Cable, Black, Pure Copper, 18/2 (18
AWG 2 Conductor), 7 Strand, 1000ft 237+28= $265
Flaking cable out onto the boat deck works well for a few hundred feet, but slip rings are cheap to add to the cable spool to make deploying and retrieving the cable
Get an IL-6-FS for the end of the cable, and a BH-6-MP. 6 conductor, each individual pin is self sealing. Use the MC series if you need smaller dia. Get a spare IL-6-FS and use the other 4 conductors for straight Ethernet so you can plug the laptop directly in if your troubleshooting the sea cable -- Andrew
SEA CON http://seaconworldwide.com
Woods Hole use mineral oil in all PBOF (Pressure balanced/oil filled) systems. Thrusters have NNL690-G Oil Fortifier added for lubrication. $74/gallon It's normally used in gear boxes and transmissions. http://poweruplube.com/nnl690-g-oil-fortifier
Teflon jacketed wire is the way to go or SOOW rated extension cord
holds up for years. SOOW stands for: S = Service Cord
(600 Volts), OO = Oil Resistant both inside insulation and outside
jacket, W = designation for weather/water resistance.