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Tips for developers

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Jiří M. aka Menion edited this page Feb 7, 2019 · 4 revisions

Tips for add-ons

On this page we would like to collect all nice and possible ideas on add-ons.

This collection has one main purpose. Because creating add-ons for already existing application like Locus Map is quite easy, and because our time possibilities are very limited, we want to offer some inspiration for freelance developers or for those, who start with developing for Android.

Routing service - OpenRouteService.org

OpenRouteService is another routing service based on OpenStreetMaps project.

Where to start

Additional links

Security application as "Alert in case of crash"

Inspired by topic on help desk.

When device "feel" high stress (from g-sensor) or weird side position, and in few seconds speed drops to zero, app should show pop-up windows with alert which user can cancel in 30-60 seconds by long press of special button. If user didn’t react - device will send message to predefined contacts with alert and current position of user.

In this video - it is shown how it works in Garmin (as You see - device will also generate sound alert)

Feature may be implemented as add-on automatically working together with active Locus Map, but also as separate application independent on any other navigation application.

AIS/NMEA for the sea sailors

The Automatic Identification System (AIS) is an automatic tracking system used on ships and by vessel traffic services (VTS) for identifying and locating vessels by electronically exchanging data with other nearby ships, AIS base stations, and satellites. When satellites are used to detect AIS signatures then the term Satellite-AIS (S-AIS) is used. AIS information supplements marine radar, which continues to be the primary method of collision avoidance for water transport.

Information provided by AIS equipment, such as unique identification, position, course, and speed, can be displayed on a screen or an ECDIS. AIS is intended to assist a vessel's watchstanding officers and allow maritime authorities to track and monitor vessel movements. AIS integrates a standardized VHF transceiver with a positioning system such as a GPS or LORAN-C receiver, with other electronic navigation sensors, such as a gyrocompass or rate of turn indicator. Vessels fitted with AIS transceivers can be tracked by AIS base stations located along coast lines or, when out of range of terrestrial networks, through a growing number of satellites that are fitted with special AIS receivers which are capable of deconflicting a large number of signatures.

Further reading on Wikipedia

The information is coded into AIS/NMEA sentences:

There are some open source decoder libraries on the net, e.g.

Basic implementation should cover the following aspects:

  • connect to a NMEA data stream provided via TCP/IP
  • decode the NMEA stream
  • visualise the AIS targets (ships) on the map and update their position/orientation as soon as a new AIS packet from this ship is received

A more thorough implementation might cover the following features:

  • plot the track of moving ships
  • provide a list of current targets with their speed, course and position

The last step might be:

  • calculate the possibility of a collision with one of the current ships (position and time of collision)
  • provide some filter functions to declutter the list of targets
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