A few questions from a noob


I am about to pull the trigger on the Spider and I was wondering if I could ask a few questions. I am currently building a project on the panda II and the RAM is a huge problem for me. I am trying to buffer a lot of data and then write it to SD but the memory is just too small. I would love it if GHI had a board like the Panda with 4-6 megabytes of RAM. I have looked around and I cannot find anything affordable with these specs. So here I am looking at the Spider. Considering an analog data logger can cost 400 dollars this looks great. Exspecially when I may need 10 to 20.

  1. How do I hook up sensors if the are not “gadgeteer” sensors. For example the lilypad accelerometer sensor or something like it?

  2. How do I power this from batteries? Is there a barrel power input attachment?

  3. Does anybody know if there is an analog accelerometer sensor made for this? If not what kind of sample rate can I get from the accelerometers?

  4. What is the scale of the accelerometers? +/- how many g’s…

  1. You use the “extender” modules and hijack the pins you need. Buy a few :slight_smile: And also you should probably buy the MakeBread module that has been discussed here.

  2. You need to make sure you get the DP power module. DP means Dual Power and it can take power from USB as well as having a barrel socket.

3&4 I have no idea on sorry.

Fez Cobra is very similar to Spider (they are both based on the EMX module) so is another form factor you could consider if Gadgeteer isn’t your thing…


Thanks! You are truly a FEZ hero!

I think the Spider is a better option due to the price. Maybe not when you consider the addons. It would be great if there was a RAM addon for the Panda.

Maybe this is the wrong place to ask but I wonder if you could recommend a board that had 2+ megs of RAM and an SD slot. The Arduino form factor may not be better than the Gadgeteer in a lot of ways but it is what I started with.

The Cobra is real nice but the price is just too high for my project. The ideal price of the board is around 50-70 dollars. A company is paying for this and they are getting impatient :wink:

Does every plug slot have a 3v3 and 5v as well as ground? That is cool if so.

Yes, see this link:

$120 vs $150 for the mainboard. Hmm, maybe you’re not managing expectations :slight_smile:

Seriously, they are the same at their core. I think the real difference is the intent of Gadgeteer was always that you could quickly get past the hardware inter-connects portion of the design and get into code. If you’re looking for something that has the same guts and capabilities, and you’re going to be doing lots of hardware hacking anyway, then Cobra to me seems like it might actually be worth it.

Especially when you consider that a Spider main board still needs a DP power module and an Ethernet module, oh and an SD card module, there’s another $47, and the Cobra comes with them all on the board :slight_smile:

Thanks Brett,

I actually don’t need an Ethernet but I understand what you are saying. The specs of the Hydra are really great. It fits the bill and offers me the RAM to buffer all that data before I write it to SD.

I am torn. The Hydra has a faster processor (which in my case may make a difference) and I found the basic kit in England where it is just a little more than a Netduino. Is it correct that it has 16 Megabytes of RAM? WOW!

Aside from the DP power module I can just attach the sensors via the extenders or cables form the cable pack?

SO I need the Basic pack as well as:

  1. DP power module
  2. SD card reader
  3. Extender cables

And that should cut it.

Now if you can just find me a +/- 8g analog accelerometer sensor (not chip) :wink:

Just realized I said the Spider when I meant the Hydra!


now you’re talking Hydra? OK, then the price of that is substantially less than Cobra. And then again, Cerberus is cheaper yet again (and looks awesome by the way!) so it will come down to how flexible you think you might want (based on how many sockets you have available) and if you are a leading edge or a bleeding edge kinda guy :slight_smile: In order of “polished” netmf implementations the Spider shines, the Hydra comes next and the Cerberus is still new and “alpha” (but is based on the 4.2 framework).

8g’s, geez what are you measuring ? How does this one look? http://www.hobbytronics.co.uk/sensors/accelerometer/adxl345

For cables/connections to non-Gadgeteer boards/devices, all you need to do is to break out the wires from the cable and use them individually. Obviously the “protection” you get from sockets is lost if you do this so the emphasis on connecting things nicely is all on your head :slight_smile: The good thing is you can take a standard Fez Gadgeteer cable and chop it in half and then you’ve got cables to connect to two mainboard sockets :slight_smile:

While I was typing that last update, you posted the Hydra/Spider post :slight_smile: Yes now I understand a little more. And YES it has 16Mb flash module.

I have looked at every board out there and the Hydra is a complete steal for the specs. I guess I just wish they could offer it in an panda form factor. I am not averse to trying new things and really what is the difference other then the shields. I will still attach and interface in exactly the same way in my code. The problem come when you have different pins that don’t fit 1 plug. They seem to have a good choice of attachments and I suspect it will work great. The 16 megabytes gives me so much RAM I could easily have a 10000X4 int array and not come close to filling the memory.

Thanks again Brett. You are a very helpful member of this community.

@ rgm - rumors are flying about some kind of new board being released soon. I suggest waiting a bit longer before pulling the trigger. :wink:

I wish I could wait Ransomhal…project is already two weeks behind schedule (bachelors project).

To be honest I dove into this embedded thing headfirst and have been buying a board every week…so I am sure I will pick it up when it come out. There are some really neat stuff coming down the pipeline at duinomite…they have a sort of 30 dollar raspberry pi but with the inputs of an arduino in the works…

Just placed an order for a hydra and duinomite-mega (for fun). I am an old BASIC guy from TRS COCO II days so I am looking forward to that.

It would be real cool to see BASIC on the PANDA or Hydra…

Closest you’ll get to BASIC is VB.NET with NETMF 4.2 (SDK release pending)

Want to lose threading and memory management and go back to BASIC? :frowning:

Maybe VB is alright buy BASIC way too “basic” literally.

See my blog post from 2 years ago http://tinyclr.blogspot.com/2010/03/can-basic-run-through-c-this-is-crazy.html I did just that but the source codes are no longer available. They were lost while moving the domain.