Arduino Hardware Choices - Help Needed

Forum 2005-2010 (read only) General Frequently-Asked Questions
1

So here is the disclaimer up front. I am new to Arduino and to diy portible electronics in general. I've been more of a mechanical and computer diy'er until now.

So here is my story/question... I am an avid sailor and want to design a GPS driven display very similar to this. SpeedPuck ⇀ Velocitek

Obviously I am going to start off with basic projects and work up to the that project. However, I would like to purchase most of what I need up front.

Here are the following hardware requirements I believe I will have for the project:

  • GPS /w logging capability
  • Battery operated (6+ hrs)
  • SD Storage (2GB)
  • LCD Display (maybe x2)
  • Buttons (3-4+)

Q1) Should I go with the Arduino Mega over the Duemilanove due to the number of components I plan on having? and increase in processing power?

Q2) GPS Shield Options - One contains SD logging while the other doesn't. If I go with the one that does have the SD option would I also be able to log other Calculations from the Arduino in that configuration?

Or, would it be better to go without it and add an stand alone SD module to the Arduino itself?

http://www.robotshop.com/adafruit-gps-logger-shield-kit-arduino-2.html

Q3) GPS Units - Any thoughts?

By order of price

I really appreciate any help or insight you guys can provide.

Gannon

2

Fair warning: I've not used a GPS module.

Q3) GPS Units - Any thoughts?

Two of those are 3.3V devices. You will need a "level shifter" (I think that's what they're called).

This one is a bit cheaper and works at 5V...
http://www.parallax.com/Store/Sensors/CompassGPS/tabid/173/CategoryID/48/List/0/SortField/0/Level/a/ProductID/560/Default.aspx

3

You might be able to get all of this done with the Duemilanove; in fact, I would start with it, and the rest of the components, mainly because most people use it over the Mega, there is a ton of code out there already (and a lot of people have done GPS interfaces; plenty of threads on these forums), and it is geared toward the newbie.

There is also another reason to try this, and that would be to, in the "final product", incorporate the LilyPad 328 into the design - you would have to figure out what to do with the GPS module and LCD, but in theory you could make a "stack" with the LilyPad 328, GPS, LCD, and your buttons, and put it inside a slick round case, and end up with something real similar to that puck (especially if you can find a small LCD; maybe a Nokia cellphone serial GLCD could work?).

But first, prototype it out with the Duemilanove, then move it to the LilyPad once you are comfortable that everything is working; pick your other components (GPS and LCD, mainly) to fit in the footprint of the LilyPad. Sparkfun has plenty of options, there; if I was doing this I would go for these parts:

Arduino Duemilanove:

LilyPad:

FTDI breakout for LilyPad:

GPS Module:

MicroSD breakout:

LCD:

Plus your sundry buttons and such.

When you get to the LilyPad final, you will also want these, likely:

LilyPad LiPower Board:

LiPoly Battery:

Plus whatever case you want to put it in...

The only part that you may want to put more research into would probably be the GPS unit; I picked one of the small ones (I think it is smaller than the LilyPad) - but I don't know the particular merits/downsides to each GPS module; it may or may not be best for your application.

Hope this helps in some manner...

:slight_smile:

[edit]Another note: Some of these parts are 3.3V, some are 5V; you may need level shifters and such to get things working - which could make the "compact" bit more difficult; I am not sure how you could get around this (without having to create your own custom PCB layout)...[/edit]

4

Duemilanove: simpler, cheaper, better support
Mega: near guarantee on enough memory and program space, PLENTY of pins

The choice is yours, I'm currently using a duemilanove for my project...
It needs to operate 6 servo's, two serial devices (one through a software serial), an LCD shield and at least a single light sensor.
That combined uses up a total of 20 pins, the duemilanove has.. 20.
Now I have a multiplexer in the system so I can expand my sensor equipment, but still, its cramped!

If you feel you'll have more stuff connected to it, go for the mega, if not, the duemilanove will suffice.

5

Thanks guys. I think I'm going to go the Duemilanove route. I appreciate the insight and tips, saves me time and frustration.

6

However, I would like to purchase most of what I need up front.

I'm curious. Why would you want to buy most parts up front?

I find that, as I learn more, my ideas become more refined, my focus becomes clearer, and I may realise I can do much more with just a different selection of parts, or do everything I need with less.

Sorry if I am prying. That isn't my aim.

7

Well it was to save on shipping. But I got impatient and built my own Arduino starter kit so I can start learning the basics.

If your curious I pretty much have the parts figured out for the first breadboard version:

Duemilanove - $29.95
Wall Adapter - $6.00

Micro SD - $44.95 - [u]Breakout Board for DOSonCHIP FAT16 FAT32 uSD Module - BOB-08215 - SparkFun Electronics vs SparkFun microSD Transflash Breakout - BOB-00544 - SparkFun Electronics or SparkFun SD/MMC Card Breakout - BOB-12941 - SparkFun Electronics... I understand the difference between the two at a high level but if somebody would care to explain the difference in detail about how to integrate the later two (cheaper) versions I would greatly appreciate it.

GPS Unit - $34.99 http://www.parallax.com/Store/Sensors/CompassGPS/tabid/173/ProductID/644/List/0/Default.aspx?SortField=ProductName,ProductName - Thanks to Coding Badly

I was going to use a GPS shield but I'm now against it because of how I may need to orient the GPS unit in the case.

SD Card - $10 Start with 2GB
Buttons (2 minimum) - $2.00
Buzzer - $2.00
Battery - $5.00 Going to start with 9v and move to this http://www.liquidware.com/shop/show/BP/Lithium+Backpack
Otter Box - ~$20 not sure what size yet http://www.otterbox.com/waterproof-cases/

I left the display for last because I had an idea when buying parts to play around with early on.
Initially I was going to go with this LCD SparkFun Serial Graphic LCD 160x128 - LCD-08884 - SparkFun Electronics but after thinking about what I really need/want I think I can get away with the following:

1x 10 LED Bard Graph (at bottom) - $0.75 LED Display's
2x 4 Digit LCD Display - $5.50 LCD Display's

So thats $11.75 vs $69.95... granted I probably need to add some parts so I can fit all of these components onto the main board. i'm thinking like this Arduino Playground - LCD3wires ... any thoughts?

The plan is to try and come in under $200 for the breadboard version. And then maybe start using even smaller components and get it under $150 for following revisions. That would be a savings of 50% off the commercial product. I have a lot of friends who race on other boats as potential clients if I can get this to work correctly. Granted that is WAY off in the future as I have a lot of coding to learn.

8

Interesting

If it's important, it might be worth checking that you can use SD card higher than 2GB.
AFAIK, there was a restriction that limited SD projects to 2GB because of MS restricting of FAT32, and SD licensing. (I was recently told that is no longer a problem, but I couldn't find any evidence)

'Arduino' - $15
GPS $35
box $20
SD socket $ 4
display $ 6
Misc $10 - buttons battery buzzer
SD $10
fudge $10 Contingency
Total = $110

If you can keep the PCB small, it might be pretty cheap to make one off from, e.g. from Sparkfun.

9

Please let us know how you progress. There's plenty of space in the Exhibition forum! :slight_smile:

10

I'll start a build log when I get things and start playing... I'm sure I'm going to need help and support. Thanks for getting me on the right track everyone.

11

I'm sure I'm going to need help and support

I'm sorry but we've run out of those. Could I offer some harm and hindrance instead?

HA! Just kidding! :smiley:

12

I'm sorry but we've run out of those. Could I offer some harm and hindrance instead?

I love it. I'm going to steal that line!

13

So it looks like I have made my first mistake and I don't even have parts yet...

2x 4 Digit LCD Display - $5.50 LCD Display's

Uses ICL7106 controllers and it seems like everything I see related to arduino builds use HD44780.

Ok, so I've google searched and realize the difference. Correct me if I'm wrong but it seems that the HD44780 standard is much easier to interface to arduino.

For my display I need to be able to read numbers from upwards of 20ft. So I need to find a LCD that can output characters at a reasonably large size (1in+). I need a very basic 4 digit display as I intended to get.

14

I need a very basic 4 digit display as I intended to get

Not necessarily. Several folks on the forum have used "graphic characters" to display large numbers. I've not done it myself so I can't provide any details.