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OneWire Library

admin    All projects, Library     AVR, Dallas, Library, Maxim, OneWire

History

The OneWire protocol which in fact needs two wires (data and ground) is fantastic for many reasons: you can have a very long cable (250 feets), you can have multiples of devices on this cable and with a simple code you can poll those devices to get temperature, voltage, switch position, wind speed, etc.

This protocol was developed by Dallas Semiconductor (now Maxim-IC).  Many flavors of devices can be connected to an OneWire port. You can see them at Maxim (http://www.maxim-ic.com/1-Wire.cfm) web site!

OneWire Features

• Cable can be long
• Devices take their power from the data line
• Multiples devices can be used on the same cable
• Each device has is own ID (48 bits serial number)

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Source Code

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4 Comments to “OneWire Library”

• 

  Felipe January 17, 2012 at 9:25 pm

  I don't understand "the mask", the argument to the functions, could you give me an example??, it's the port?
  Input:            mask : Where the device are on the port?
   
  also what's the function of this code?
  //**************************************
  //            D E F I N E
  //**************************************
  // User dependent BEGIN
  #define ONEWIRE       0×01                            // BIT
  #define ONEPIN    (*(volatile unsigned char *)0×36)    // PIN register
  #define ONEDDR    (*(volatile unsigned char *)0×37)    // Data Direction Register
  #define ONEPORT    (*(volatile unsigned char *)0×38)    // PORT
  // User dependent END
  it's the configuration of the pins/port/ddr??, if it's case i don't understand how to setup, thanks for the web site, it's cool!!
• 

  admin January 17, 2012 at 11:14 pm

  It’s make so many time I wrote this code, I don’t really remember about the mask, it could me the bit port pin for the define you could make #define ONEPN PIND (if you use port D)

  Sylvain
• 

  Felipe January 18, 2012 at 4:24 pm

  Maybe you have an example of use (project), can you send me in a e-mail??, felipe.paredes@gmail.com, that will be useful for me. thanks for the answer
• 

  Jean-Claude February 20, 2012 at 10:55 pm

  Hi Sylvain,
  I'm also interested in a simple example code in C using this lib, I also want to read the temperature from a DS18B20.
  Thanks
  jc.dasilva@free.fr