Micro Basics

I recently saw a cute little, inexpensive GPS module offered at Digikey that includes dual PCB antennas (I assume, maybe it's one large antenna?). The company offering it, Antenova, focuses on antennas, in particular PCB antennas, and I expect this module mainly showcases their technology.

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The Antenova Radionova RF Antenna Module uses a SiRF III chipset, and makes available many I/O for that chipset that aren't available on other modules.

Unfortunately I do not have the SiRF III datasheet (appears to be available via NDA) and the Antenova datasheet is somewhat misleading. It took me more than a few hours trying out various combinations of connections to get it to output NMEA data, but I was finally successful.

In its default mode, it outputs NMEA data at 9600kbps on power up with the pins connected as follows:

I had two problems, both stemming from following the datasheet:

• The datasheet suggests that ED1 and ED0 default to high and low, respectively, but that boots the module in ROM mode. After connecting them both to ground (Flash mode) it booted up fine.
• The datasheet suggests that if you aren't using TM, connect it to ground. Well, it also says that TM is an output (I haven't looked at it, but perhaps it's the PPS signal...). So I'm leaving that floating, and it's working now (I did have it connected to ground, but I haven't tested it since I had the boot mode set correctly).

At any rate, it's an inexpensive, small, complete GPS module, and I hope it works well in my application. I also hope this proves useful to others looking at this module in the future, though honestly I'm documenting it mainly for my own future reference...

-Adam