A Directional POI implementation...

[PhilHornby]

OK - A "Poor man's" Directional POI implementation

This was mentioned to me some time ago, but I never actually tried it for myself:

If you place an alerting Custom POI adjacent to another one, and assign it a lengthy custom audio file containing 'silence', it can mask the presence of the first Custom POI, when travelling in one direction.

Custom POI alerts are normally queued and played one after another, but they will be abandoned, if you have moved out of range, when it is their turn to play.

The following diagram is a Mapsource screen print and shows 3 POIs, each of which have a Proximity Alert associated with them. As noted elsewhere, the 'circles' drawn by Mapsource are not representative of the active area of the alert, but do show roughly the distance along-the-road, where the alert is active.

The POIs "EASTBOUND ALERT" and "WESTBOUND ALERT" have different informational audio associated with them. The POI "OneMinute" has audio comprising of one minute's silence (well it's more or less silence, with a bit of background hiss )

If you start on the left of the picture, and select a route that takes you EAST, then the EastBound Alert audio will play, followed by the silence associated with the POI "OneMinute". There will be a visual indication of "Westbound Alert", but you will have passed outside its active range by the time the silence has finished, and it will not play. (The opposite is true, when travelling East-to-West; only "Westbound Alert" will be audible).

Clearly this takes quite a while to set up and is only suitable for certain scenarios.

A set of test files to demonstrate this effect, is available for download:-

• A pre-built .GPI file (Directional.gpi. The audio is in .WAV format for maximum compatibility).
  
• The source files used to create this .GPI file, (in .zip format).
  

You can copy the Directional.gpi file directly to the unit's POI directory, or place it on an SD card (recommended). In addition to the 3 POIs shown in the diagram, there are two more (non-alerting) POIs. These are called "EAST Waypoint" and "WEST Waypoint" and can be used to simulate a route past the 3 alerting POIs.

With the .GPI file loaded, proceed as follows:

1. Enable GPS Simulation Mode
   
2. Using "Where to?", find the POI "West Waypoint", under the Custom POI category "Directional"
   
3. Use "Map" to display it.
   
4. Use "Set Loc" to set it as the current location.
   
5. Press "Back" and select "East Waypoint", then "GO"
   
6. Say "yes" to "Do you want to simulate driving this route?"
   
7. Note the audio that plays!
   
8. On arriving at "East Waypoint", set a simulated route back to "West Waypoint"
   
9. Note the different audio that plays!
   

Note: the route Start/End points are deliberately placed off the road, so that the unit has no pre-conceived ideas about which direction it is facing. This prevents lengthy detours in the simulation ,while it finds somewhere to turn round!

There are screenshots of the process from a Nüvi 250W here.

[M8TJT]

Great idea . When you have done it for over 10,000 cams, please let us know.

[Kremmen]

Once I understand it fully I reckon I could probably build something into my GPX converter files to cover this.

I just need to find some time to investigate.

What would help would be an existing camera in CSV format and what would be required in a GPX format. I'm assuming the single line in the CSV would need duplicate lines in the GPX or even a new category to link to the silence.wav ?

... or I could supply my VB 2010 Converter Source Code to Phil as he understands it
_________________
DashCam:
Viofo A119 V3
Car Average MPG :

[MaFt]

I'm guessing you would need the exact heading of the camera so you can roughly work out where the extra points should go? If you need them I could possibly create an extra set of CSV files that can have the data, though you may be able to use the CoPilot Live 8 CSV files as these have heading data.

Thing is, not all roads are nice and straight like this, what about those where the camera is on a bendy road? how would those 2 extra points be placed if it was all automated?

MaFt

[M8TJT]

The iGO download is in .CSV format with heading, although it's labelled as .TXT. But of course no cam numbers.

[PhilHornby]

Well it might be possible to automate something with regard to Camera Alerts - you have the heading data, and an appropriate road could possibly be located using the OpenStreetMap data. It would not be easy though, with an ever present danger of masking other alerts in the area. (Garmin have one or two of their directional alerts the wrong way round , so we'd be in good company!).

Personally, the only camera alerts that annoy me, are ones for SPECS cameras on the opposite carriageway - they're the only ones where there's likely to be a huge discrepancy between how fast I'm going, and what the Garmin has just alerted me to.

I've just discovered another effect that can be used to implement Directional Alerts:

TourGuides can be interrupted by along-road alerts, and do not restart afterwards. If an Along-road alert was playing at the time the TourGuide should trigger, they don't even start. On units with full TourGuide support, such as the Nüvi 760, the 'megaphone' symbol appears and they can be manually started, but otherwise they are effectively surpressed.

Of course, TourGuides are not speed-related, but they could be used for red-light cameras that don't cover every entrance to a junction. Place the TourGuide in the centre of the junction, and have along-road alerts (with (say) 10 secs silence attached), on the approaches where they shouldn't sound. The 10 seconds of audio, is there to make sure the Along-road alert starts before the TourGuide and is still active when you arrive in the TourGuide alert zone.

Here is a re-worked example of the previous alerts, using this method:



So: Going EAST (ie left-to-right), the EASTBOUND ALERT TourGuide triggers and plays its audio. This has finished before you arrive at STOP EAST. This alert plays 10seconds of silence, but otherwise has no effect travelling in this direction.

Arriving at STOP WEST, its 10 seconds of silence plays and is still playing when you arrive in the detection zone for WESTBOUND ALERT; thus surpressing it. Travelling in the opposite direction obviously has the opposite effect, so that EASTBOUND ALERT only plays going East and WESTBOUND ALERT only plays going West.

The test files are available for download:-

• A pre-built .GPI file (Directional_TG.gpi). The audio is in .WAV format.
  
• The source files used to create this .GPI file, (in .zip format).
  

We see you’re using an ad-blocker. We’re fine with that and won’t stop you visiting the site.
Have you considered making a donation towards website running costs?.
Or you could disable your ad-blocker for this site. We think you’ll find our adverts are not overbearing!