One Wire interface to BeagleBoard?

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1

I’m interested in doing some temperature monitoring with the beagleboard. I’ve seen the chip at http://www.sparkfun.com/commerce/product_info.php?products_id=245 but don’t know how I would connect to a one wire interface.

The DS18B20 chip looks really interesting to me, and I’d really like a string of several of the chips connected to a single interface, I just don’t know where to get started.

I’ve got plenty of linux experience, and even more developing C/C++ programs, but very little with actually hooking together electronic components.

Any pointers are appreciated.

Wim.

2

The easiest way is to use w1-gpio, but I haven’t tried that myself yet.

3

I’m interested in doing some temperature monitoring with the beagleboard. I’ve seen the chip at http://www.sparkfun.com/commerce/product_info.php?products_id=245 but don’t know how I would connect to a one wire interface.

That chip has 3.3V interface so you cannot connect it directly to OMAP3. Bi-directional level shifter or some other solution is required. Maxim provides an example here http://www.maxim-ic.com/app-notes/index.mvp/id/4477

I would first try to find for 1.8V device.

The 1-wire pin is not exposed on beagleboard so the w1-gpio that Koen suggests on the other mail is your only option.

The DS18B20 chip looks really interesting to me, and I’d really like a string of several of the chips connected to a single interface, I just don’t know where to get started.

This site has some resources http://www.digitemp.com/

I’ve got plenty of linux experience, and even more developing C/C++ programs, but very little with actually hooking together electronic components.

Any pointers are appreciated.

Software-wise you need to implement a driver for the chip for 1-wire bus. See examples is drivers/w1/slaves.

  • Juha
4

1-Wire is exposed on the Beagle-xM. Please refer to the schematic. The signal is called HDQ.

Gerald
.

5

Or the lazy way (i'd use cause i am lazy :wink: ) is:

http://www.maxim-ic.com/datasheet/index.mvp/id/3834