Multiple PICs on usart network - Page 2


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  1. #41
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    Default Re: Multiple PICs on usart network

    Thanks, Andy.

    Actually, there's nothing to it, really.

    Just set up the Rx and Tx routines as shown in the graphic (substitute the pin you're actually using in place of the C.6 I've shown) and call Tx before each transmission, and Rx before receiving (or more accurately, after each transmission).

    So, at any time, only one guy is transmitting.

    And, make sure the pin you're using is set for digital I/O, of course.

    Anand

  2. #42
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    Default Re: Multiple PICs on usart network

    Quote Originally Posted by ardhuru View Post
    Thanks, Andy.

    Actually, there's nothing to it, really.
    Hello Anand,

    Thank you very much buddy in advance for your replying me.

    In brief, I am beginner at PIC world, and absolutely not expert such as you bro.

    Would you mind if you share an applicable sample here (for Master and slaves), please?

    I would deeply appreciate for your understanding and most valuable support.

    Regards,

    Andy
    Last edited by andymuller; - 27th January 2015 at 17:47.

  3. #43
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    Default Re: Multiple PICs on usart network

    test post to open a closed thread (I have a pending post)

    can be deleted once another post is added (thread auto-closes if I remove this one)
    Last edited by Demon; - 1st June 2024 at 03:34.
    My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.

    Not as dumb as yesterday, but stupider than tomorrow!

  4. #44
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    Default Re: Multiple PICs on usart network

    I can post here just fine. I see it opened.

    Ioannis

  5. #45
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    Default Re: Multiple PICs on usart network

    This comm scheme sounds like ISO-9141. Been around for years.

  6. #46
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    Default Re: Multiple PICs on usart network

    Quote Originally Posted by Ioannis View Post
    I can post here just fine. I see it opened.

    Ioannis
    Me too. But if I removed my post, the thread closed again.
    My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.

    Not as dumb as yesterday, but stupider than tomorrow!

  7. #47
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    Default Re: Multiple PICs on usart network

    Quote Originally Posted by DaveP View Post
    This comm scheme sounds like ISO-9141. Been around for years.
    I saw a mention further up the thread about 1-wire comm.

    OBD-II signal protocols. ISO 9141-2. This protocol has an asynchronous serial data rate of 10.4 kbit/s. It is somewhat similar to RS-232; however, the signal levels are different, and communications happen on a single, bidirectional line without additional handshake signals.

    https://en.wikipedia.org/wiki/On-boa...hake%20signals.


    I'm planning on using standard 2-wire hardware USART.
    My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.

    Not as dumb as yesterday, but stupider than tomorrow!

  8. #48
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    Default Re: Multiple PICs on usart network

    Quote Originally Posted by Demon View Post
    OBD-II signal protocols. ISO 9141-2. This protocol has an asynchronous serial data rate of 10.4 kbit/s. It is somewhat similar to RS-232; however, the signal levels are different, and communications happen on a single, bidirectional line without additional handshake signals.

    https://en.wikipedia.org/wiki/On-boa...hake%20signals.


    I'm planning on using standard 2-wire hardware USART.
    Car automakers had to do it with better electrical characteristics I guess.

    I'd also choose 2 wires USART classic setup. Tested and guarrateed to work just fine.

    Ioannis

  9. #49
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    Default Re: Multiple PICs on usart network

    Quote Originally Posted by HenrikOlsson View Post
    ...The last byte (13) will not go thru properly because the tranceiver chip is switched from Tx to Rx mode in the middle of it....

    /Henrik.

    The original project was just a personal home alarm system.

    But now I'm designing a controller for flight sim that I plan on marketing. I'm considering using a combination of everything said in this thread, including your comment.

    - separate TX and RX lines.
    - tri-state busy line for slaves.
    - tri-state busy line for master (for future expansion).
    - enable/disable TX in slaves.
    - add an extra byte in transmission so no data is lost during transition between enable/disable (if I can't identify exactly how to avoid dropping that byte).
    - slaves only talk when spoken to by master.
    - prefix in communication identifies which slave is targeted.
    - slaves can "raise their hand" to speak using slave busy line.
    - basic checksum.
    - highest speed supported by 16F1455, 16F1937, 16F18855 and 16F18877.
    - two 4K7 pull-up resistors on master (or maybe 10K, remains to be determined).

    That's pretty much what I have identified to start.
    My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.

    Not as dumb as yesterday, but stupider than tomorrow!

  10. #50
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    Default Re: Multiple PICs on usart network

    For those that are curious about 1-wire communication, check out Dallas 1-wire:

    https://ww1.microchip.com/downloads/...S00002658B.pdf
    My Creality Ender 3 S1 Plus is a giant paperweight that can't even be used as a boat anchor, cause I'd be fined for polluting our waterways with electronic devices.

    Not as dumb as yesterday, but stupider than tomorrow!

  11. #51
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    Default Re: Multiple PICs on usart network

    Interesting article.

    Thanks for sharing.

    Ioannis

  12. #52
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    Default Re: Multiple PICs on usart network

    Quote Originally Posted by Demon View Post
    For those that are curious about 1-wire communication, check out Dallas 1-wire:

    https://ww1.microchip.com/downloads/...S00002658B.pdf
    Thank you Demon
    Valuable data
    Appreciate.

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