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Propeller Serial communication question. — Parallax Forums

Propeller Serial communication question.

JMLStamp2pJMLStamp2p Posts: 259
edited 2008-01-04 11:46 in Propeller 1
Good evening,
I need to interface the propeller with a "I^2 C" communications protocall wich is Sync.'s
Is this possible with the Propeller ?
I understand that this protocall is timing critical being Sync. instead of Aysync.
But due to the speed of the Propeller I thought it may be fesible.
Our delima is that we need to do this through a pair of trancievers, one being the Master generating the clock signal and another being the slave.
If anyone can give me some information on this subject it would be very helpful.
Thanks,
John Logan
JMLStamp2p@aol.com
·

Comments

  • DgswanerDgswaner Posts: 795
    edited 2008-01-03 16:04
    there is an I^2 C object under protocols in the propeller object exchange.

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    "A complex design is the sign of an inferior designer." - Jamie Hyneman, Myth Buster

    DGSwaner
  • deSilvadeSilva Posts: 2,967
    edited 2008-01-03 16:09
    There are four objects or routines to do I2C, the most recent one even a very fast machine code version.
    But all implement master mode!
    It is not clear from your note (or rather I fear it is...) whether you want to use the propeller as I2C slave? This has still to be done, I think. But will be possible with ease for 400kBit and with dificulties also with highest speed (1MBPS).

    Being synchronious is no problem. There is also a technique called "bit stretching" which can relax things considerably..

    Post Edited (deSilva) : 1/3/2008 4:17:40 PM GMT
  • Mike GreenMike Green Posts: 23,101
    edited 2008-01-03 16:12
    There are several objects (I/O drivers) for specific I2C devices and two general purpose I2C drivers in the Object Exchange. The Propeller normally uses an I2C EEPROM for storage of its programs and those same general purpose I/O pins can be used for other I2C devices.
  • simonlsimonl Posts: 866
    edited 2008-01-03 16:26
    I seem to remember someone worked on I2C slave a long while ago, but I can't find the thread.

    If I remember correctly though, it all went quite when someone from Parallax suggested that Philips would want their royalties for any SLAVE implementation...

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    Cheers,

    Simon
    www.norfolkhelicopterclub.co.uk
    You'll always have as many take-offs as landings, the trick is to be sure you can take-off again ;-)
    BTW: I type as I'm thinking, so please don't take any offense at my writing style smile.gif
  • deSilvadeSilva Posts: 2,967
    edited 2008-01-03 16:30
    simonl said...
    it all went quite when someone from Parallax suggested that Philips would want their royalties for any SLAVE implementation...

    This is no longer the case...
    And had never been for software solutions, but for silicon only!
    And it depends on how you "call" it cf. ATMEL with their TWI smile.gif
  • Mike CookMike Cook Posts: 829
    edited 2008-01-03 16:32
    Here's the link to i2c_toy:

    http://forums.parallax.com/showthread.php?p=617209



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    Mike
  • hippyhippy Posts: 1,981
    edited 2008-01-03 17:58
    deSilva's right and as far as I2C licensing goes now; "I2C licenses under the remaining patents in the program will be free of any royalties, for any use of the patents after October 1, 2006, without any prejudice to any claims for past use whatsoever".

    www.nxp.com/products/interface_control/i2c/licensing
  • simonlsimonl Posts: 866
    edited 2008-01-04 11:46
    Hey, thanks for that hippy smile.gif - I guess we can go-ahead and create all sorts of I2C slave devices now, YAY!

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    Cheers,

    Simon
    www.norfolkhelicopterclub.co.uk
    You'll always have as many take-offs as landings, the trick is to be sure you can take-off again ;-)
    BTW: I type as I'm thinking, so please don't take any offense at my writing style smile.gif
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