SiRFdemo for PCs (and PocketPCs*)
Advanced configuration for SiRF based GPS receivers!



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1. To take a peek at the advanced settings of your GPS receiver and to see how it was set in the factory, or modify some of these settings


2. Your GPS is behaving oddly and you want to reset it to factory defaults


3. You want to verify the revision of the Firmware loaded on your GPS receiver - (insight on SiRF FW naming)

1. To use SiRFdemo you need a PC or a laptop and a way to connect your GPS receiver. For a compact flash GPS, you can use a PCMCIA/CF adapter, for a wired GPS, a DB9 serial port or USB via a USB/DB9 adapter and of course a Bluetooth GPS receiver with built-in BT or a dongle
2. You need to identify the correct COM port used by your GPS. It will be COM1 for a serial GPS generally and for a Bluetooth GPS, a right click on the connection will show you the port
3. Launch SiRFdemo - choose the correct COM port and select 4,800 (or 38,400 for a Bluetooth GPS) (fig 1)
4. SiRFdemo only provides detailed information in SiRF mode so do \Action\Switch to SiRF (fig 2) and you will see the various windows "light up"(fig 3)

Fig.1 Fig.2 Fig.3

Fig.4 Fig.5

1. Operating Mode (Degraded/Altitude Hold/Dead Reckoning) : défines the operating mode when optimal reception (4+ satellites) is no longer available
2. Track Smoothing : wrill smoothen the track to remove the "jumps" resulting from the natural "inaccuracy" of the GPS system (10/15 meters) - disabled by default
3. Static Navigation : will "freeze" the position at very low speed to cancel out the drifting resulting from the natura "inaccuray" of GPS - should be disabled for pedestrian use - see below for details
4. DOP : filtering based on the quality of reception
5. DGPS : controls the activation of SBAS (WAAS in the US and EGNOS in Europe) - since SA (Selective Availability) was removed in May 2000, mainly useful to check the integrity of the GPS signal for critical use in planes and in shipts - available on SiRFstar III with FW 3.1 and above
6. Power : to configure power saving trickle modes

Fig.6 Fig.7

1. \Navigation\Static Navigation\ (fig. 6)
2. Click on "Disable" then SEND (fig. 7)
3. Verify that the change has been recorded by the GPS by calling the Navigation Parameters
4. Please note that the default setting will return with a "factory reset" command or when the battery runs out
5. Analyzing: As you can see in 9a, representing a walk with silumtaneaous logging, the impact of SN on a SiRFstarIII GPS is pretty significant, better accuracy, better distance measurement, with Xtrac 2 there is no notable impact and its status as a "non-pedestrian" friendly GPS remains.

BEFORE - AFTER - On the Field

Fig.8 Fig.9 Fig.9a

1. To keep your settings : \Action\Switch to NMEA Protocol\ select 4,800 then Send (fig. 10 et 11)
2. To set your GPS back to its factory settings : \Action\Initialize Data Source\Factory Reset then Send (fig. 12 et 13)

Fig.10 Fig.11

Fig.12 Fig.13

1. "Technical Forums" - >>HERE<<

quote:

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Originally posted by scalor

only this string in the receiver output view

255(0xFF) Error Data

and in the error view

Comm CE_break

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