ds2408

HardwareWizard

does anyone have some code that will talk to a ds2408 ???


i would like an example of how to talk to a single ds2408 and how to talk to 2 ds2408's on the same 1-wire.


thanks


HardwareWizard
·

Jon Williams

That's a pretty new part ... if you've got them in hand, you should blaze a trail (write the code) and share it with the rest of us.

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Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA

Jonb

"Device communication follows the standard Dallas Semiconductor 1-Wire protocol"

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3818


So do a search for 1-wire... actually try a few different words, the forum search acts weird Setup a framework for the 1-wire protocol, then read the datasheet to determine what the IC is expecting over the 1-wire bus.


Edit: After reading over the datasheet, this IC is terribly complicated to use. There are much simpler ICs on the market for expanding outputs or switching considerably more current if this is your goal... What is the intended application if I may ask?

As for talking to 2 of them, their 64bit address is·lazered onto the rom. The 1-wire protocol has provisions for selecting the IC using the distinct serial number. Other methods involve switching between different channels with an additional switch IC. I've never tried this so no details sorry.

Post Edited (Jonb) : 4/1/2005 4:57:38 AM GMT

Jon Williams

I just looked over that part sheet too -- I don't think it will work with the BS2p as it uses non-standard timing having to do with the 1-Wire interface (specifically reset). So much for specifications....

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Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA

Lars50

Hi Hardware Wis

I had the same issue with my DS2406, for a while. It seems that the 1-wire is not the most popular devices in this forum. I posted some code in Jan, which worked for a 2406. The 2408 is more complex but my feeling was that if 2406 can work then a 2408 should do as well, just more code.

Lars

Gadgetman

If you can't use it with a BS2p because of timing problems, why not stick a DS2480(b) between the BS2 and DS2408?
(The Ds2480 takes TTL level Serial and converts it to 1-Wire protocol. Quite a nice chip, really)

The REALLY good ting with 1-Wire chips is just that; 1 wire, no matter how many chips you want to control.
As the chips have 64bit serial numbers, which can be easily read, they are very good for electronic locks.

Being able to address all of them at the same time, by using the SkipROM command, you can order all the similar chips to do the same operation, all at the same time.
(Like locking ALL your door-locks, starting temperature readings, or... )
Take a look at the different chips and you'll soon notice that special commands(like starting a conversion) all have unique Byte values, and that only the READ commands are the same.
(When a 1-wire chip receives a command it doesn't understand it will just be ignored)

Unfortunately, though, they are 'a bit' quirky to work with.

Jon Williams

You need to check the timing of the DS2480. The BS2p meets "standard" 1-Wire timing guidelines; the DS2408 does not (requires longer reset pulse). The DS2408 may in fact work with the BS2p, but it will just be luck as -- again -- the DS2408 has different timing specifications from the 1-Wire standard.

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Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA