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Getting Started with the Cobra II (eco) Board


#1

Hi -
Just received the Cobra II (eco) along with a ENC28 ethernet module and 2 RS232 modules.

Is the link below what I should reference to get started
https://www.ghielectronics.com/docs/21/first-netmf-project

This will be our 2nd prototype of a product which will eventually ship to the industrial marketplace. Our 1st prototype was based around a netDuino + 2 (netMF).

Has anybody ported a netMF application from another platform to the Cobra?
I know there will be code changes for IO, peripherals, etc…just wondering if there are any pitfalls or gotchas I am not aware of.

Also, our production board will be based around the G120 SOM and not the Cobra II. With
the Cobra II being a gadgeteer board is there going to be a lot of work porting the code from the Cobra to our production board based on the G120 SOM and other peripherals we will add, i.e. ethernet, 2 serial ports, SD card, usb client?


#2

If you know you will not be using gadgeteer then I suggest not to use it from the beginning. The other option is to use gadgeteer and continue using it in your final product. I mean keep the vice as is even if there are no gadgeteer sockets.

Welcome to the community.


#3

Hi Gus -

Yes, I would prefer to NOT go the gadgeteer route. What G120 based dev kit would I use instead of the cobra II (eco)?


#4

Hi Andre -

So, are you saying I do not need to connect my peripherals (ethernet, rs232, ect) via the Gadgeeter sockets on the Cobra II?

I would instead connect my peripherals to the solder pads on the side of the board?
If this is the case, where would I go to purchase NON gadgeteer ethernet, rs232 modules?

Is the Cobra II (eco) the best G120 based dev board for NON gadgeteer project?


#5

@ mhardy - When testing a SoM for the first time, we generally have people use the Gadgeteer board, if you are familiar with NETMF then you can use the G120 SoM breakout board, http://www.ghielectronics.com/catalog/product/431. This board is not commonly used by beginners to NETMF but if you do not need the simplicity of the plug-n-play of Gadgeteer then you can definitely use the G120HDR board.


#6

Gary -

I get error 404, file not found when going to the link you posted?

So, the Cobra II (eco) is the wrong board for my (non Gageteer) development, but the G120HDR is?

I will have to essentially build my own ethernet and rs232 modules?


#7

@ mhardy - it’s because of the period at the end of the link, https://www.ghielectronics.com/catalog/product/431 . You can still use our Gadgeteer modules with the breakout module to wire and use pure NETMF, https://www.ghielectronics.com/catalog/product/405 . Otherwise, you could use your current modules and create the appropriate drivers.


#8

Gary -

So, I need to return my Cobra II (eco) because it will NOT work for NON gadgeteer development, correct?

I will need to order a G120HDR & breakout modules for this development, correct?

The breakout modules allow for direct connection to the G120 SOM pins, correct?

Assuming above is correct, the ENC28 & rs232 modules will communicate directly to the NXP peripherals and there will be NO gadgeteer commincations, correct?

You have the drivers already created to communicate with the modules using pure netMF, correct?

I am unclear on: "Otherwise, you could use your current modules and create the appropriate drivers."
Are you talking about the enc28 & rs232 modules I bought from you…I hope NOT, I hope you are talking about some module(s) that we built ourselves?

BTW, we have not built any modules on our own. The plan for our production board is to use your reference designs (BOMs, Eagle Files, etc) wherever possible, this is all available, correct?


#9

@ mhardy - You can still use your Cobra for pure NETMF development by using the expansion headers on the side of the board. As well as using it a reference design. I believe in our previous conversations off the forum, you were going to use the ENC28 as your networking, correct?

Depending on how many prototypes you are building the G120HDR is about $20 cheaper per board. But you do not have to switch strictly to use NETMF directly.

Also, if you are using our Gadgeteer modules, the breakout module allows you to skip the Gadgeteer software layer by wiring those modules directly to the board through the expansion header and giving the G120 SoM access to those modules without using the Gadgeteer sockets.


#10

Gary, I did not realize you were the Gary I first talked to!

Yes, we will use the enc28.

The reference design we will use is the FEZ Cobra II Net (the one you mentioned previously in an email.) Is it impossible to purchase on of these boards?

If we cannot purchase one of these boards, then all I need to order is the breakout modules, wire the breakout(s) to the expansion header and connect the modules using the ribbon cable(s), correct?

You guys already have the pure netMF drivers for these modules, correct?
Is there documentation on which expansion header pins I need to wire the modules to in order to support your driver(s)?


#11

@ mhardy - Unfortunately, there is a MOQ of 100 for those boards. However, someone in the forum might have one they could sell. I would post something in the “Off Topic” board.

[quote]If we cannot purchase one of these boards, then all I need to order is the breakout modules, wire the breakout(s) to the expansion header and connect the modules using the ribbon cable(s), correct?
[/quote]
Correct

No, our driver will be for the Gadgeteer layer but it is pretty simple to port those to pure NETMF.

Compare the schematic of the Cobra, http://www.ghielectronics.com/downloads/schematic/FEZ_Cobra_II_SCH.pdf with the pinout of the module you are using.


#12

OK, I will order the breakout modules.

Jeez, porting drivers is rarely simple!!! Does the premium library make this simple in some way, i.e. something like calling the constructor of the ethernet object where the constructor takes in the pins to use for ethernet?


#13

If you don’t want to use the Gadgeteer framework then you’re going to have to rewrite driver code.

If you don’t want to rewrite driver code you’re going to have to use Gadgeteer.

Which one you choose is up to you.

Using Gadgeteer framework really makes no difference in this scenario except potentially you have a greater chance of finding issues in the extra layer (rather than introduce new issues in your rewrite of the driver).

Transporting between a Gadgeteer app and a G120 SOM based device is trivial as well. Each Gadgeteer socket is really just a collection of pins, so if you route those pins on your custom board to where you want the sensors/devices to connect, then you can still deploy the same code and it’ll just work. How you physically access those pins on a Gadgeteer socket, either through a breakout module or my new personal favourite the g-plug, or through the direct module like you have with the ENC28, is irrelevant at the end of the day.


#14

Ahhh, thanks Brett -

I should have just looked at the schematics!!!
I did not realize the sockets are just and easy way of accessing the G120 SOM pins.
I was of the impression that Gadgeteer worked on some sort of communications scheme, like I2C, SPI, CAN or something?

So, one more question on Gadgeteer…I assume Gadgeteer is akin to a Hardware Abstraction Layer (HAL), which allows module vendors to develop to one standard, regardless of the underlying CPU, SOM, etc…is that correct?

Crap…I would have ordered some G-plugs yesterday along with the breakout modules, if I would have known about them!!