09-02-2016, 10:54 PM
(09-02-2016, 10:21 PM)MarkHaysHarris777 Wrote: ... you are arguing against my empirical evidence and experience.
pfeerick, this is science not opinion; I'm not interested in arguing about it either. Put a battery on your gps or not. I choose to, and it works for me. You are free to take my expert advice or not... or like we say in the forums-- YMMV
Do NOT confuse a question as to where you get the information for a statement you make as being an argument against your 'empirical evidence and experience'.
I didn't start going on about how I've used multiple different GPS chipsets, starting with the EM-406 which really did take 2-3 minutes to get a lock, and doesn't have any memory backup. I have been using them for several years for position hold and automated waypoint navigation of both model aircraft and multi-rotors, so know how they behave with different environments.
So there is absolutely no need steam-roller other forum members simply because they asked you where you got the information from. Especially when if you consider the question was in relation to acquisition time, and if you want, I'll upload the video I took showing the MTK3388 acquiring a position fix in under 30 seconds with no battery backup to demonstrate that what i have said makes absolutely no sense what-so-ever.
btw, whilst I highly recommend the Adafruit Ultimate GPS Breakout due to their excellent quality products, guides and support, since it is US$40 + postage, if you want a GPS unit that is much more sensitive, is just as easy to use, and has a very comprehensive datasheet and protocol guide, you can't go past the uBlox NEO-7. They aren't the newest GPS chipset in the uBlox range, but at AU$15-16 (inc. postage!) on eBay, you can't got wrong with them. They come with a ceramic antenna, and have the uFL an external GPS 'mouse' (antenna). You can use them like most other GPS chips in Serial NMEA mode, or can use the proprietary (but open) UBX binary protocol, making it possible to write some very efficient GPS processing code.