Reply To: GPS Project – A few simple questions

[Bizzmark]

Peter, thank you for your answers. You gave me a lot of info. A few follow-ups, if I may:

What would I be losing without an IMU? As I understand it, IMU basically helps maintain GPS position for a while if signal is lost? Or does that even work with Navit? Would I lose constant compass heading without it?

Doesn’t the GSM unit require a GSM carrier SIM card, and thus, an active account with a GSM cellular carrier? If true, I feel like the IMU unit would be better for me; I’m not looking to spend a lot as this will be secondary to Google Maps, GSM coverage in the US is paltry, and I feel as though IMU might maintain GPS lock a bit better in concrete jungles I visit, like Boston (ie. lots of multipath signals). What do you think?

 

Sorry, I was unclear about the whole antenna thing – I wasn’t saying I’d be unplugging the uFL connector often; rather, if I used it, the uFL connected antenna would be permanent inside the case. But the real question was do I need a specific GPS antenna or will a standard WiFi antenna work? Sure, I can experiment with different ones, but I’d like to order everything I’m likely to need all at once (tonight, ideally). And, how does the ceramic passive antenna compare to the active one? (those made by OzzMaker) .. since they’re both rated at 28dB, is the only true difference being that the active one can have a longer cable? I think this is generally true based on some articles I’ve read, but a few say that active reception can be better.

I’ll have to check specs on the X725, and see if I can keep 3.3v trickling on the GPIO rails. Roughly how much power drain will the GPS-IMU v3 board continuously take at idle?

 

Thanks for all your help. This is going to be a fun project.