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FEZ Cobra II on battery or other viable options


#1

Dear folks,
I’m going to start my first project and I’m choosing .NET Gadgeteer platform being a .NET developer. I’m not very into electronics so please excuse me for major mistakes; this is one of the reasons because I’m choosing this platform, the socket labelling system looks great for people like me.

My final project is a wireless networked “thing” with the ability to stream lo-res videos from a couple of cameras, read some (compass, distance) sensors, drive some (4 max) motors. Maybe something that would required some time and learning but I want to start with the right tools from the beginning.

I’m tempted by Cobra II board with already built-in Wi-fi but I’m stuck now that I’ve seen it doesn’t have a D socket, required to couple with a battery module like AABAT-GM-394

Given the requirements I have, what’s my best option?

Thanks in advance,
mt


#2

Welcome to the forum.

You can power the Cobra from a USB power pack, or directly from a battery.

Streaming video might be a bit of a challenge, depending upon the speed of the data stream. What kind of cameras are you going to be using? Serial? USB?


#3

Thanks Mike,
glad to hear I can power with USB or battery.

The camera I’d like to use is something like CMRAU-GM-283 https://www.ghielectronics.com/catalog/product/283 : is the board too slow to handle it? Do you have any suggestion for another board, e.g. Spider?

Thank you again,
mt


#4

@ m.bagattini

The Cobra II uses the G120 module which is more current than the EMX module used in the Spider. The speed of both modules are about the same.

To run more than one USB camera, you will need an external USB hub.

There are the questions of what will be the resolution of the camera images, and what frame rate you are expecting. A 320x240 you are going to get around 3-5 frames per second.

Generally, the streaming of real time video is not an application for .NET MF devices. A the present time, C# and VB manged code is interpreted, which makes for slow running. The video drivers are also in manged code. This makes for lower maximum frame rates.

Some more metrics are really needed to determine if the Cobra II, or any MF device, will meet your needs.


#5

Regarding a power source, do a search for “LiPo Rider Pro” on Seeed Studio. I am building/completing a prototype using the Cobra II (eco), the “LiPo Rider Pro” as a power source (connected to solar panel and battery), monitoring sensors and communicating the results using a long range xbees.

Not sure about streaming video, not sure the Cobra II would be up to it. Maybe a better bet is to try the FEZ raptor or G400HDR. As @ Mike said you will need do some benchmarking. I admit I do not have any with streaming video/pictures with gadgeteer. If I had a project to do video streaming I would considering using one of the latest “hardkernel odriod” boards (not gadgeteer).


#6

As far as I can understand from both your replies it seems better to raise the horsepower a little bit. I was attracted by the Cobra II because of all the integrated stuff, but I’m sure everything is also available for the Raptor, maybe I’ll need a little help to figure things out, looks like I’ll need additional modules for power source, wifi and so on.

I don’t need a fluid throughput, low framerate is ok too but with Raptor capabilities I should be safer. Also, Raptor has a whole bunch of sockets, and it seems that wouldn’t need any additional hub.

As for the power source: is it possible to prototype using for instance USB Client SP Module
USBSP-GM-330 connected to my computer and than later jack it to a battery pack like those used to charge cell phones (Amazon: http://www.amazon.com/External-Battery-Pack-Limefuel-L130X/dp/B00BZD6QCW/ )?

I have a tons of questions and many more doubts, I’ll try to figure out one at a time…

EDIT: maybe Hydra could be a good alternative between Raptor and Cobra/Spider, in terms of power?
EDIT2: seems that wi-fi on Hydra is very basic, I’ll skip this option


#7

[quote]As for the power source: is it possible to prototype using for instance USB Client SP Module
USBSP-GM-330 connected to my computer and than later jack it to a battery pack like those used to charge cell phones (Amazon: http://www.amazon.com/External-Battery-Pack-Limefuel-L130X/dp/B00BZD6QCW/ )?[/quote]

Sorry for bumping this!


#8

I’ve powered the Cobra 2 from a LiPo Rider Pro from Seeed Studio. I just used a USB cable to do this.

The best part is that the Lipo Rider Pro has a passthrough USB connection so you can do development with it connected.

I added a small modification to the Lipo Rider so that I could detect when DC power had failed an it was now on battery power. I used this to send me an SMS. :slight_smile: