Arduino & the DS2482-800

[Ben Madison]

So after some thought son how best to implement a robust 1-Wire network on an Ardunio, I happened across the DS2482 from Maxim-IC and think it might be the answer to unrestricted 1-Wire devices on an Ardunio. They make 2 different versions, one with a single 1-Wire channel (DS2482-100) and one with eight 1-Wire channels (DS2482-800).

The chip (SOIC-8 or 16) is a little cumbersome to work with but there are a few places out there that make SOCI to DIP boards so long as you can handle a soldering iron with a little bit of finesse. The one I've linked to already comes with solder, all you need is flux, and iron and a steady hand.

As for the specifics in operation it is essentially like this:

1. The DS2482 has a built in 1-Wire master with advanced bus management features (slew control, strong pullup, etc)
2. The DS2482 has a native I2C interface for control (SDA/SCL pins on Ardunio, Pin 20/21 on the Mega)
3. The Ardunio already has I2C implemented through the Wire Library. And since you are only doing command and data retrieval through this protocol, it should make it pretty simple to implement as these are basic functions.

Once I get everything in place, I'll start the proto and hopefully keep everyone posted of my results.

If anyone has any thoughts/concerns/comments, please let me know.....

As a side note: I've also thought of using a USB Host shield and the LinkUSB for robust implementation of the 1-Wire.....parts are in route, but I think I'll tackle the DS2482 first....when I start the USB proto I'll open a different thread...

[Vadim Tkachenko]

Hello Ben,

> So after some thought son how best to implement a robust 1-Wire network on
> an Ardunio, I happened across the DS2482 from Maxim-IC and think it might be
> the answer to unrestricted 1-Wire devices on an Ardunio. They make 2
> different versions, one with a single 1-Wire channel (DS2482-100) and one
> with eight 1-Wire channels (DS2482-800).

-800 is the way to go.

> 3. The Ardunio already has I2C implemented through the Wire Library. And
> since you are only doing command and data retrieval through this protocol,
> it should make it pretty simple to implement as these are basic functions.

Not just retrieval, actuators can be controlled with DS2405, 06 and
08. But supporting those won't be much work compared to the whole
affair of making 1-Wire available.

> As a side note: I've also thought of using a USB Host shield and the LinkUSB
> for robust implementation of the 1-Wire.....parts are in route, but I think
> I'll tackle the DS2482 first....when I start the USB proto I'll open a
> different thread...

USB Host is indispensable for this app. Arduino itself won't be
sufficient to operate the whole system for some time to come, the
brains are still on Android. ADK connection will occupy the USB host.
I don't know if you can use additional USB Host Shield on a board that
already has it - say, the Mega ADK.

--vt

[Ben Madison]

The beauty about going this route is that 1-Wire is native to the DS2482...the only "programming" required is understanding the commands you need to send over the I2C link and getting data back across it.

Also, I believe the DS2405 has been replaced by the DS2413

And as for the USB Host, I didn't think about the fact that the ADK version already has a host USB controller on it.....good point on that front. I have a shield in route so I might try hooking it up to there to see about that.

As for what is running the show (Currently the android device) what about something like Raspberry Pi? I think it runs a slimmed down version of Linux (Debian maybe?)....just a thought but it's small foot print would definitely fit in the "Screw it to the wall" arena. (Of course there are none available at the moment, but hopefully soon they'll get more put together....

Ben

[Vadim Tkachenko]

Hello Ben,

> As for what is running the show (Currently the android device) what about
> something like Raspberry Pi? I think it runs a slimmed down version of Linux
> (Debian maybe?)....just a thought but it's small foot print would definitely
> fit in the "Screw it to the wall" arena. (Of course there are none available
> at the moment, but hopefully soon they'll get more put together....

The point of running the brains on Android is: one click installation.
The most formidable obstacle for 99.999999999999999% of people having
seen this project is the hassle of connecting the pieces - and there's
plenty of them.

Can DZ be run on Raspberry Pi today as it is? But of course, it can be
run on any Linux or Mac OS that has decent Java VM. Will I do anything
about making sure it works there? No, because it doesn't get the
project closer to the goal: one click installation.

One HUGE advantage Android (which is essentially a shiny cover on top
of Linux as far as DZ is concerned) is ready-made, high quality, ever
improving UI. That comes second after ease of installation.

Can Arduino code be modified to serve as a counterpart for anything
other than ADK accessory controlling it? With ease, it was designed
that way - all you have to do is redirect the I/O stream from being
AndroidAccessory (extends Stream) to any other Stream - SerialN will
work just fine. Unfortunately, right now I can't afford time to work
on it. But it is on the master list.

> Ben

--vt

[Ben Madison]

Raspberry Pi doesn't support JVM yet...actually just read that!

I hear you on the ease of install though...that would take a good portion of the issues away I can imagine.

Ben

[Tim Small]

On 16/06/12 19:39, Ben Madison wrote:
> all you need is flux, and iron and a steady hand.

I've been told that flux+solder paste - applied with a pin (and either a
fine-tip iron, or a micro heat gun) is an easy way to go for soic
soldering - you can hold the IC down with hot-melt if you like.

Personally I think the I2C route is likely to be the best on. I know
someone who's used 1wire<->I2C<->LinuxI2Cstack before successfully.
I'll see if he has any tips.

Tim.

[Ben Madison]

The SOCI to DIP converter boards I linked to already comes with the solder on the pad so it is just a matter of flux, a small enough tip and holding the chip steady...although they have a groove where the chip fit apparently?

Appreciate you asking around for me on the I2C interface.

Ben