I want to upgrade my R/C lawnmower, add some fancy cyborg stuff like tracking, turning, positioning. I want to send a feed back to my ground station to report the data, to process in a rasp-pi, or laptop application.
I started reading about the GPS modules, looks straight forward - I hook it up, and if I can get a signal - it sends a serial data stream for me to process. I was wondering if anyone had advice before I pick out which one to buy - what to look for and / or avoid.
I see the NEO 7m is the same thing as NEO 6m, except it comes with the compass and accelerometer? Is the compass the same thing as accelerometer or are they different devices? Will I more readings / precision from a NEO 6m, and select a separate compass/accelerometer DOF module - or is the module on the NEO 7m just as good, and will save me the effort of extra wiring & space?
I see the NEO 7m is the same thing as NEO 6m, except it comes with the compass and accelerometer?
No, the NEO 6/7/8 are just GPS devices. Maybe you are looking at board that has a NEO-7 chip and a compass chip.
Otherwise, the 6 and 7 aren't different in ways that would matter to most hobbyists. Their accuracies are the same. The 7 has a few extra GPS channels and (will/does?) support the European Galileo GNSS, but its cold & warm start times are a few seconds longer. Check the specs at ublox for the gory details.
I have found that the NEO-6 will provide 16Hz updates, even though the spec says 10Hz maximum. Curious! I do not know if the NEO-7 has a similar (or better) update rate.
When you get around to software, you might be interested in my NeoGPS. It's smaller, faster and more accurate than all other libraries, and it can be configured to parse only the fields that you really use, saving even more program space, RAM and CPU time. The examples are properly structured to avoid the pitfalls in most other libraries' examples. It even has an example for parsing the raw NMEA data during an RX character interrupt. This can save even more processor time, and it helps your sketch to be more immune to other libraries that take too long.
NeoGPS also has the most accurate distance and bearing calculations. At small distances, other libraries can be off by 40%.
Thank you for the advice and link to the libraries, they will be handy.
I just need to figure out if the combination GPS / compass module is the same thing as having a seperate GPS module, and compass module - that would take up more space and wiring. If anything else is faster or more accurate, I'm sure it comes at a cost - which I would probably upgrade to that after I get experience with the standard one.
[Is] the combination GPS / compass module is the same thing as having a seperate GPS module, and compass module - that would take up more space and wiring.
Yes, they are functionally equivalent. In either case, they would be accessed on separate pins. But the software won't know whether the devices are on one PCB or two... If you have questions about a certain module, post a link to it.
I would avoid using a shield that forces you to use certain pins.
Ob second thought. It probably better for me to use a seperate GPS and compass accelerometer, until I know what I am doing. I can mount the sensor anywhere else I want instead of being merged to the GPS.
My first NEO 6M was delivered today. That ultra-tiny antenna cable with super mini RF snap-in connector is broke. The tiny wire is so small and brittle.