/Geocaching Take 2

Geocaching Take 2

The major problem when I tried to use Mio C230 to find geocaches is that by default the static navigation is turned on. What is static navigation. Murphyfields has found a great link about static navigation. Here is the quote about static navigation from SiRF.

93. Explain the static navigation parameters.

Since SA was turned off, we now disable static navigation as our default, and we recommend that you do also. When it is enabled, if velocity is below 1.2 m/s for 3 seconds we will freeze the position, and leave them frozen until velocity exceeds 1.4 m/s (so there is a bit of hysteresis in the solution).

123. What criteria are used to enable and disable the static navigation filter?

Static navigation is a mode designed for motor vehicles, which causes the position to become pinned at one location when velocity is determined to be low enough. This is designed to make navigation systems operate more reasonably when the GPS Selective Availability (SA) signal degradation is turned on. When the navigation software determines that the vehicle velocity is less than 1.2 m/s for 3 seconds, the position is pinned to its current position. It remains pinned until either velocity is detected above 1.4 m/s, or position is computed to be 200 m from the pinned location.

This explains why the NoniGPSPlot stopped working (frozen) when I used it on foot. To disable static navigation, you need a utility called SirfTech. You can download it from here. Create a directory called SirfTech under ScriptPrograms and put SirfTech.exe in it. You can use FileMan CE to run it or create an entry on the desktop. Please refer to this post if you don’t know how to add it to the desktop. I have also created an icon file for it.

SirfTech is a powerful and complicated utility. I wish there is an easier way to toggle static navigation, but there isn’t. I will tell you a bit about how to use SirfTech to disable static navigation. Please note that, DO NOT RUSH on doing these steps. Wait for a few seconds before do the next step.

The first time you run SirfTech, you need to set the com port. Click on Com. Set the Comm Port to COM2: GPS_COM . Baudrate to 4800. Click on Open. Wait for a few seconds to let the program connect to the GPS. Click on OK.

Now, we need to switch to SiRF mode. Click on Nmea and then Set Serial Port (Switch to SiRF). If the Baudrate was not set, set it to 4800. Click on Set and then OK.

We can now disable static navigation. Click on Sirf and then Static Navigation. Uncheck the Static Navigation checkbox. Click on Set and the OK.

Before you run other applications, it’s better to return the GPS to NMEA mode. Click on Sirf and select the last opiton Switch to NMEA Protocal. If the Baudrate was not set, set it to 4800. Click on Set and then OK.

Whew! That’s quite a few clicks to disable static navigation. Now you can exit SirfTech and start your GPS application.

When I first attempted Geocaching, I used NoniGPSPlot. I didn’t like it. I used MioMap this time. I entered the geocaches’ coordinates into MioMap using DegDec format. (In MioMap, do: Map -> Menu -> Coordinate) You can find the coordinates in DegDec format when you click on other conversions on Geocaching.com. I then added these location as POIs.

With these preparations, I was able to find our very first goecache! Yea!