I’m building a prototype for a tracking system using GPS and i need some good precision and reliability since the prototype will be used on a remote area under some trees.
Does the GPS module (Part # GPS01-GM-325) has good quality? It is possible to attach an external antenna? Before i order this unit i would like to know what kind of issues/problems it may have…
GPS01-GM-325 uses the u-blox neo-6 engine. U-blox is a well known and respected company in the field. I doubt you will find an engine that is much better than this.
The data sheet quotes an accuracy of 2.5m CEP. This will be with a good antenna in a clear location away from any sources of reflections etc. The signal will degrade significantly if you are under trees (especially if wet). This will definitely reduce your accuracy.
By the pictures, the cable between GPS antenna and module seems very small, do you know if is it possible to add an extension (some sort of U.FI male/female)? I need to place the antenna 1 or 2 meters away from the GPS module
The neo M8 is better because it supports glonass and Galileo. Glonass can be a bit unreliable. Galileo is going to start launching its FOC satellites from this summer so it would be well worth having in a year or two. I’ve not really used glonass so I don’t know how much it helps. I do know that it has had a few spurious incidents over the last year.
Of course you would need to build a custom board to use the M8.
On your pharos project you are saying "At the present time, there are difficulties running this code under Gadgeteer. ", since i’m planning to use a fez cerberus with a USB host module, does your code will work on it?
Are you using that USB GPS on your gadgeteer project? Which mainboard are you using? If there is a working hardware combination, i’ll be happy to use it.
Dam… tricky boards… Too much “hidden” possibilities… I choosed cerberus because it is cheap and small.
I can use fez cobra eco (like Mike does), but i was planning to use 2 A-type slots from cerberus because i want to read some analog inputs and set some digital outputs. Cobra has only one A-type slot, but seems that the side has plenty of I/O ports. Are they easy to use/set like gadgeteer sockets? Is there any better option?
Just one more thing about Cobra II Extender Board… i see a 12V pin on the side, does it mean that cobra II motherboard is capable of output 12V? I need 12V to power a small IC with low power consumption, this way i can get it from the board.
No, it cannot. If you look at the Cobra 2 schematic, the wire it calls “12V” is the input from the barrel jack. If you supply greater than 12v on that, you’ll get something slightly lower than the input voltage because of the diode drop in D3. If that then happened to be closer to 12v than 9v for example, then you might be able to use it. But it’s not regulated to 12v like you would typically want to use.
I’ve been using the Adafruit Ultimate GPS Module with the Cobra II to log my business mileage and which sites I’ve been working on. The module works perfectly without an external antenna and just sat on the passenger seat.