Create a Yun from scratch from Leonardo.

Hi,

I always been a fan of the Arduino, how to recreate the official boards yourself with components. But with the release of Yun, I dont see how this is easily possible anymore.

So I was wondering, what if I use a Leonardo board and add the linux/wifi side of Yun onto it. So that also mean find some replacement for the Atheros AR9331.

Any tips/ideas where to start?

Thanks

As capabilities move up the ability for DIYers to duplicate at home goes down, just a fact of life. The size/capability achieved by the Yun requires packaging skills well beyond my abilities and even if someone can duplicate this it would be unlikely to get a price below what Arduino is selling them for.

If you want to do something similar but not in as small a package there are lots of options, check out the openwrt hardware table. You need to have similar capabilities in RAM, Flash and processor and there are lots of options with these. On the MCU side you need to have a UART that can be dedicated to communicating with the Linino side, the Leonardo, Mega, and Due all meet this.

I am playing with a Buffalo WZR-600DHP and a Carambola2 combined with Arduino Mega and Due.

The Buffalo has twice the Flash and RAM and the processor clock is 1.5x of the AR9331. This box though is much larger than the Yun all by itself so when you add the MCU you are even bigger than that.

The Carambola2 has pretty much the same specs as the AR9331 on the Yun and has the potential to make a package much closer to a standard Arduino with a shield.

It isn't hard to get all the Linino software running on a similar Openwrt platform and since the Arduino system is available for any of their MCU's that part is almost trivial.

Hi, thank you for your helpful answer!

I am very familiar with OpenWRT and buffalo routers. I compile my own openwrt images and play with them all the time. Thats why I was so interested in Yun but at the same time disappointed because its too complicated to clone.

Didnt thought about looking at the hardware sheet openwrt supports and Carambola 2 looks nice.

Size is not important for me, I dont mind it to be much bigger. I just want to be able to customize the board like those other arduino's.

Back to the drawing table! Thanks

If your already familiar with the Openwrt and routers, all you need is one with a serial connection you can get to and a level shifter for 2.5V or 3.3V to 5V and one of the Arduinos with a UART available.

You can do anything but flash sketches to the Arduino through Wifi at that point. I'm still working on the ICSP connections but you need at least 4 gpios for that.

I use a linksys WRT54GL with an arduino in nearly exact the same way as the yun.
I have inplemented a software reboot. In other words send a command over the serial monitor to tell the arduino to reboot. This rebooting is then executed via a pin putting power on the reset pin. A software reboot is not compatible with uploading a sketch.

It works nice and I want to use the same methods with a yun and arduino over USB. My main arguments for the yun are price, size and setup time.

What you won't get with the openwrt setup is the fast baud rate the yun has between the leonardo and the lininio.

By the way: after plenty of reading I decided not to use level shifters for the TTL communication. It worked fine for me for more than a year now.
Best regards
Jantje

The Dragino2 is able to run Linino. The wiki page for that machine details how to make an effective Yun from a Dragino2 and a leonardo board. It would appear that the limiting factor in making a Yun system is the size of available flash memory on your router. Linino makes a 16 megabyte image and the flash memory on many routers is less than that.

Linino makes a 16 megabyte image and the flash memory on many routers is less than that.

Linino makes a 8 megabyte image, an other 8 megabyte is mirror in case restored is needed.

8 megabytes is still too many for many of those openWRT routers. 4 megabytes of flash is pretty typical.

I did some research the last few days. And dragino ms14/M32 and carambola 2 looks very interesting.

The challenge here is probably make it compatible with Linino and a working bridge. And the only way I see it here is to use the Atmega32u4 chip and not Atmega328

laapsaap:
The challenge here is probably make it compatible with Linino and a working bridge. And the only way I see it here is to use the Atmega32u4 chip and not Atmega328

And what is the reason you say so?
Best regards
Jantje

I got confused with something I read. But yeah I take it back, should work with either. I just ordered some extra 328p and 32u4 to test both.

I think the main reason why Arduino went for the leonardo is because it has a onboard usb which frees up pin 0 and 1.
Now on the yun pin 0 and 1 are taken for the lininio communication but you still have all "normal pins" (except for pin 7 it seems) and the USB.
Best regards
Jantje

Just so you know, I would LOVE to see pictures of your home made yun-like. The Buffalo, the Linksys... please! Show them! :slight_smile:

EDIT: added picture

Here you have a top view of my robot. You can see the "arduino pile" in the bottom and at the top you see the linksys antenna's
If you want a specific shot you'll have to hurry to ask it as I'm planning to get the linksys out and replace with a yun.
Best regards
Jantje

Jantje:

[quote author=Federico Fissore link=topic=209495.msg1545293#msg1545293 date=1389645436]
Just so you know, I would LOVE to see pictures of your home made yun-like. The Buffalo, the Linksys... please! Show them! :slight_smile:

Here you have a top view of my robot. You can see the "arduino pile" in the bottom and at the top you see the linksys antenna's
[/quote]Is this a "virtual" view? :~ Just asking... :grin:

Ralf :wink:

PCWorxLA:
Is this a "virtual" view? :~ Just asking... :grin:

Ralf :wink:


Thanks for pointing this out
Best regards
Jantje

EDIT: this also contains a image link but no image to be seen.
Edit my bad wrong link

Jantje:

PCWorxLA:
Is this a "virtual" view? :~ Just asking... :grin:

Ralf :wink:

Thanks for pointing this out

Much better now, thanks! 8)

Ralf :wink: