Sailing by sound
Lancelot Robson <Lancelot.Robson@metaswitch.com>
(With advice available from
- stephen.remington@yahoo.co.uk
- Brian Jones <bdj23@cam.ac.uk>
- Neil King <Neil.King@uis.cam.ac.uk>
The protocol that enables instruments on boats to intercommunicate is NMEA (National Maritime Electronics Association - 'national' being US but globally adopted). There are two standards in current use and one under development (definitions from Wikipedia below).
It is essential to understand that 0183 and 2000 are quite different, 2000 is not simply an upgrade of 0183. Though many boats run successfully on 0183 new ones will install 2000. Some, like Vala, are in transition from 0183 to 2000 and there are interface devices that get the two protocols talking to eachother. Some boats probably have neither NMEA standard installed.
I think it would be worth exploring if a box could be created that would simply plug into the NMEA2K backbone and translate the NMEA sentences into voice output. The backbone provides 12v power and all devices send their sentences along the backbone (including those derived via NMEA0183 if the interface is installed}. The new box would need the NMEA2K connection and an audio out jack for connection to amplifier and speakers to suit. More excitingly, the box could receive audio instructions from crew via a microphone input and respond with the specific data requested. So, a call to the box for 'depth' would cause it to translate the latest depth sentence from NMEA and voice output actual depth immediately. It could of course provide actual bearings too and also read out deviation from intended course as Vala's plotter currently does visually. Any data on the NMEA backbone could be interrogated provided the box understands the voice input. Some data could be provided only on demand or if certain conditions are met (e.g. depth less than 2.5m or course deviation more than 3degrees) or the operator could set the box to speak chosen data at allotted time intervals, constantly if needed. Blind people should be able to set these choices for themselves and the box would need to be able to receive voice instructions for all necessary set up. It would not be acceptable for the setup to have to be done by a sighted person. If voice input is unachievable then a simple tactile keypad could be created. The box could respond with voiced questions and instructions to take the operator through the set up process and its later operation.
