Netduino home hardware projects downloads community

Jump to content


The Netduino forums have been replaced by new forums at community.wildernesslabs.co. This site has been preserved for archival purposes only and the ability to make new accounts or posts has been turned off.
Photo

What's needed for GPS


  • Please log in to reply
17 replies to this topic

#1 MarkWill

MarkWill

    Advanced Member

  • Members
  • PipPipPip
  • 34 posts

Posted 09 September 2010 - 10:16 PM

A couple of questions about what I'd need if I wanted to get GPS information into a Netduino. It seems I need both a GPS shield AND a GPS module. Is that correct? And, if I want to store data I'd need a GPS data logger. Correct again? A bit confused... Also, does anyone happen to know if the typical GPS support on a device of this nature (using a GPS module) supports altitude? I am a private pilot and - just for the heck of it - interested in building something for my (small) cockpit that uses GPS information. I actually have no idea if all GPS devices that follow standards have the capability to obtain an altitude. I've tried finding this out but can't find any reference to this on any of the devices I found. Thanks. Mark

#2 Chris Walker

Chris Walker

    Secret Labs Staff

  • Moderators
  • 7767 posts
  • LocationNew York, NY

Posted 09 September 2010 - 10:19 PM

Hi Mark, You need a GPS receiver to get the GPS data, and some way to store the data. The Adafruit GPS shield has both SD and GPS capabilities--so that might be a good start. As far as altitude goes, not sure. I've never used a GPS receiver very far above the ground :) Maybe someone here who is more expert in that can pitch in... Chris

#3 MarkWill

MarkWill

    Advanced Member

  • Members
  • PipPipPip
  • 34 posts

Posted 09 September 2010 - 10:27 PM

You need a GPS receiver to get the GPS data, and some way to store the data. The Adafruit GPS shield has both SD and GPS capabilities--so that might be a good start.

Thanks Chris (for the record, I'm really impressed and appreciative of the prompt and helpful responses since I signed up).

My confusion stems from the fact that if I look at the AdaFruit Shield (http://www.adafruit....&products_id=98), there is a specific message saying "Please note that this shield does not come with a GPS module, they are sold separately". So it looks like I need both, no?

Thanks again.

Mark

#4 greg

greg

    Advanced Member

  • Members
  • PipPipPip
  • 169 posts
  • LocationChicago, IL

Posted 09 September 2010 - 10:28 PM

The specs will list the max altitude but it is generally about 18k feet or so. It can't be any higher than 30k as I recall. And you don't need a shield as they all talk via serial.

#5 Chris Walker

Chris Walker

    Secret Labs Staff

  • Moderators
  • 7767 posts
  • LocationNew York, NY

Posted 09 September 2010 - 10:28 PM

Oh right, the GPS modules are a bit pricey and there are probably a few that will work. The shield provides the electrical connections--but you'll need to add the actual GPS receiver. Chris

#6 greg

greg

    Advanced Member

  • Members
  • PipPipPip
  • 169 posts
  • LocationChicago, IL

Posted 09 September 2010 - 10:30 PM

You really just need the module. Sparkfun has a bunch. I use the locosys LS22031 I think is the model number for $60. It just needs power and a free uart for serial communication.

#7 Chris Walker

Chris Walker

    Secret Labs Staff

  • Moderators
  • 7767 posts
  • LocationNew York, NY

Posted 09 September 2010 - 10:31 PM

Listen to Greg. The shields are nice because they give you SD card access and are really simple--but you can do that via a SPI breakout board as well. Also--note that some of the shields require soldering and assembly. For some, that's awesome and fun; for some, not so much... Chris

#8 MattW

MattW

    Member

  • Members
  • PipPip
  • 23 posts

Posted 09 September 2010 - 10:35 PM

According to the manual (page 12) for the em406a (compatable with the Adafruit GPS shield), altitude is reported, but I've never seen it in action. http://www.usglobals...6/em406a_ug.pdf I've doing some flying myself and looking at a similar project... :)

#9 greg

greg

    Advanced Member

  • Members
  • PipPipPip
  • 169 posts
  • LocationChicago, IL

Posted 10 September 2010 - 12:07 AM

Again most will report up to about 18k feet. It's a legal issue as high precision gps (able to report at altitude or at high speed) are actually considered munitions and restricted as such.

#10 Chris Walker

Chris Walker

    Secret Labs Staff

  • Moderators
  • 7767 posts
  • LocationNew York, NY

Posted 10 September 2010 - 12:10 AM

Again most will report up to about 18k feet. It's a legal issue as high precision gps (able to report at altitude or at high speed) are actually considered munitions and restricted as such.


Wow, I didn't know that. You are seriously a fountain of knowledge, greg.

#11 greg

greg

    Advanced Member

  • Members
  • PipPipPip
  • 169 posts
  • LocationChicago, IL

Posted 10 September 2010 - 12:19 AM

Chris think about it. :) what do you have if you can report position at high altitude and high speed? Answer: the basis for a navigation system of a ballistic or cruise missile... The government takes a dim view of that. :)

#12 Chris Walker

Chris Walker

    Secret Labs Staff

  • Moderators
  • 7767 posts
  • LocationNew York, NY

Posted 10 September 2010 - 12:46 AM

Chris think about it. :) what do you have if you can report position at high altitude and high speed? Answer: the basis for a navigation system of a ballistic or cruise missile...

The government takes a dim view of that. :)

Very good point :)

#13 greg

greg

    Advanced Member

  • Members
  • PipPipPip
  • 169 posts
  • LocationChicago, IL

Posted 10 September 2010 - 01:04 AM

I just doublechecked - it's 18k feet and 515 m/sec -- a civilian receiver can exceed either of those but not both (then it's a munition). Many manufacturers just limit their receivers to both restrictions so you have to check into each one's specs to see what it can do.

#14 Chris Seto

Chris Seto

    Advanced Member

  • Members
  • PipPipPip
  • 405 posts

Posted 10 September 2010 - 12:22 PM

Being a PPL, you will never get high or fast enough for a GPS limit to get in your way. I take a GPS with me while I fly as well, and I have never had any issues. I have even taken it up to 600MPH on an airliner, but that's no fun ;) Now, if you were flying the space shuttle, on the other hand.... :rolleyes:

#15 greg

greg

    Advanced Member

  • Members
  • PipPipPip
  • 169 posts
  • LocationChicago, IL

Posted 10 September 2010 - 12:46 PM

Being a PPL, you will never get high or fast enough for a GPS limit to get in your way. I take a GPS with me while I fly as well, and I have never had any issues. I have even taken it up to 600MPH on an airliner, but that's no fun ;)

Now, if you were flying the space shuttle, on the other hand.... :rolleyes:


Chris - I think he's trying to do a high-alt baloon so the altitude restrictions are absolutely going to hit him.

And as a PPL you don't go above 18k because it requires oxygen or a pressurized cabin, and while I don't know I'm willing to bet you don't fly pressurized aircraft. ;-)

This much I know as a skydiver. 15k is the limit without O2. Unless you're going for a high-alt jump and then you bundle up and bring a tank of O2 with you. Not a lot of fun actually.

#16 Chris Seto

Chris Seto

    Advanced Member

  • Members
  • PipPipPip
  • 405 posts

Posted 10 September 2010 - 01:17 PM

Mmmm.... I have PPL friends who have gone "above" 18K with o2 in their high performance homebuilt planes. I don't ever seem to go above 10K. I'm not sure if he wants to do a balloon. I read this: "heck of it - interested in building something for my (small) cockpit that uses GPS information." Also, you can easily build, buy and fly your own pressurized aircraft on a PPL. Look at the Lancair IV-P. For a certified aircraft, you could get a Cessna P-210, but those will go far slower than the speed restriction so you shouldn't have an issue.

#17 MarkWill

MarkWill

    Advanced Member

  • Members
  • PipPipPip
  • 34 posts

Posted 10 September 2010 - 01:26 PM

I turn away for a few hours and when I come back I am a fighter pilot travelling near the speed of sounds :-) Seriously, my needs are very modest (and not defined to any great degree yet). I just potter around in my mickey mouse little 172 at maybe 125 knots maximum and reaching 6,000 feet is a "big day" (for the fellow pilots, even under IFR the MEA's around here - or at least where I fly - are in the 3-5,000 range). So, I don't anticipate any constraints with what the GPS modules seem to be able to offer. Anyway, this is good to know and I appreciate the comments. I'm off to try and come up with some reason to actually build something that will need the GPS now :-) Thanks again. Mark

#18 Chris Seto

Chris Seto

    Advanced Member

  • Members
  • PipPipPip
  • 405 posts

Posted 10 September 2010 - 02:08 PM

Hi Mark, Just about any module should work then. Have fun! Also, I am doing a community GPS driver project. Please see: fezgps.codeplex.com Please note that the "FEZ" in the name only stands for "freakin easy" GPS, not the name of the boards.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

home    hardware    projects    downloads    community    where to buy    contact Copyright © 2016 Wilderness Labs Inc.  |  Legal   |   CC BY-SA
This webpage is licensed under a Creative Commons Attribution-ShareAlike License.