Chris, Have you read the background information on SmartBeaconing yet?
I think you're going to be fighting an uphill battle on this one. What I would do first, is to measure the data that is output from your GPS. Put a logging system on the GPS, and record the reported speed and heading values over a long period of time, say 24 hours or so while the GPS is sitting still. Now have a look at that data. Is the unit reliably reporting zero velocity, and a constant heading? Probably not. The generally recommended low speed threshold is about 5 mph. This allows for some "drift" of the reported GPS location. Also, if the GPS is reporting a location, and a heading zero degrees (as an example), and then resolves a location some distance south of that first location, you're going to get a reported velocity and a heading of 180 degrees. That heading change will trigger CornerPegging. If the GPS doesn't have a nice clear view of the sky, then you location fix is going to be worse, and subsequently more "wandering". Slow speed settings for SmartBeaconing are an issue, not due to the programming, but rather due to the "noise" of the GPS position reporting. Think of the low speed settings you have as a "squelch" knob. You've opend up the squelch to where the noise on the frequency is popping in and out, or has opened the squelch setting completely, and now are wondering why you're hearing all that racket. You either have to tighten the squelch a bit, or reduce the incoming noise level to make it quiet again. As others have indicated, profile switching can also be a problem, especially if you are trying to switch based on extremely tight tolerances. If you have profile switching where one profile is enabled at zero velocity, and the other at 4 mph, you could bounce between the two profiles due to GPS "wandering". You need to have enough hysteresis to keep from bouncing back and forth between profiles. Using a routine that sends after a maximum change in location is better for pedestrian activity. Why the desire for a double beacon on a corner? You've reported the change in heading (the important information), a second beacon is redundant. James VE6SRV On 7/29/10, Bob Poortinga <[email protected]> wrote: >> I was experimenting with a low speed Smart Beacon Profile on a T2 (with >> integrated 5W VHF transceiver) and encountered an unexpectedly high >> beaconing rate when parked. > > Are you using Profile Switching? Do you have "Transmit when swiching to > this > profile" enabled? If so, turn it off. > >> My settings were as follows: >> >> Slow Speed: 0.0 MPH TX rate: 7193 sec >> High Speed: 4 MPH TX rate: 61 sec >> Turn angle: 15 deg Max TX rate: 3 sec >> >> The shallow turn angle and fast TX rate was set to see if I could reliably >> double beacon on street corners. > > Why? This just adds QRM to the channel. > > -- > Bob Poortinga K9SQL <http://www.linkedin.com/in/bobpoortinga> > Bloomington, Indiana US > > > ------------------------------------ > > Yahoo! Groups Links > > > >
