The Fathom-S Tether Interface Board Set provides the communication and video signals needed for an ROV. It interfaces with the Fathom tether or any standard Cat5 cable with four twisted pairs of wire. It has the following features:
Through the Tether
Low-latency analog video using a differential video amplifier for crisp, colorful video over 300+m of cable. It’s compatible with any camera that has a standard NTSC or PAL video output.
Long-distance serial connection using RS-422 differential amplifiers for high-speed, reliable communication over 600+m of cable
Power on/off switch allows you to switch power on and off for small electronics. For high power switching, this can interface to a high-current power switching board.
Topside Interface
Screw terminals for tether connection
RCA video output compatible with any NTSC/PAL display or video capture card
USB serial port to easily connect to a computer
TTL serial port (5V) for direct interfacing to a computer or microcontroller
Power-on is switched on when connected through USB or powered otherwise
Jumper for reset-on-RTS to allow Arduino microcontrollers to be programmed through the tether
Optional external power input (7-20V)
ROV-side Interface
Screw terminals for tether connection
Header pin connection for analog camera
12V regulator for the analog camera, accepting up to 20V input
TTL serial port (3.3V logic, 5V tolerant) compatible with Arduino, Raspberry Pi, and DroneCode autopilots
DroneCode Mini compatible connectors for quick connection to Pixhawk and other DroneCode autopilots
5V regulator to power low-current electronics such as an Arduino
Jumper to enable/disable tether power switch
The Fathom-S Tether Interface Board Set is open-source and open-hardware, so the schematics and board files are free to view, modify, and reuse. The electrical schematic and board layout are open-source and the design files are available below.
The Fathom-S boards provide low-latency video, a serial port connection, and remote power on/off switch for tethers of 300+m length. Use with the Fathom tether or a Cat5+ network cable.