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Possible problems with the propellor — Parallax Forums

Possible problems with the propellor

faizzzfaizzz Posts: 7
edited 2009-12-09 05:33 in Propeller 1
Hi,


I needed to know about the problems than can occurr with the propellor chip. I would be grateful if anyone is kind enough to list some of the issues they have faced, or have heard about.
I have some further queries as well, it would be great if anyone took time to address them, these are:

1) Is it possible that only a few cogs(or a single cog)·can hang up, while other cogs continue to function properly?

2) Is it posible that a few cogs (or a sinlge cog) completely stop working while others keep on working?

3) Are there any other issues i should know about regarding possible problems with the propellor?

It would be great if anyone could reply to these questions.

Regards,

faizzz

Comments

  • BaggersBaggers Posts: 3,019
    edited 2009-12-08 09:38
    I've never had a single cog ( or a few cogs or even a propeller ) hang up, or stop working.
    now if your program hangs up a cog, it jump to itself, this will look like a hang, but will still be working, ( and won't stop any of the other cogs either )

    Hope this helps.

    Baggers.

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    ·
  • Graham StablerGraham Stabler Posts: 2,510
    edited 2009-12-08 09:39
    It is possible to cause one or more cogs to hang but this will be due to programming errors, there are no problems with the propeller as such.

    Perhaps you can tell us what you are worried about?

    Graham
  • heaterheater Posts: 3,370
    edited 2009-12-08 09:49
    When the Intel 286 was new we found a bug in it. Turned out that if you did a MUL by an immediate value which happened to be negative you got the wrong result. After hassling Intel about it for a while they finally sent us a thick "confidential" document describing dozens of 286 bugs. Mostly to do with the memory protection system.

    So far I have yet to hear of a Propeller bug.

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  • AleAle Posts: 2,363
    edited 2009-12-08 10:27
    It is called "propellEr".

    A runaway program will look like it "hung". You can use any of the multiple debuggers to try to find out... find them here: propeller.wikispaces.com/Debuggers+and+Emulators

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    Visit some of my articles at Propeller Wiki:
    MATH on the propeller propeller.wikispaces.com/MATH
    pPropQL: propeller.wikispaces.com/pPropQL
    pPropQL020: propeller.wikispaces.com/pPropQL020
    OMU for the pPropQL/020 propeller.wikispaces.com/OMU
  • heaterheater Posts: 3,370
    edited 2009-12-08 10:36
    But, seriously. Is it so that not even one little Propeller misbehaviour has been discovered?
    I.E. not doing what the documentation says it should except when the docs may be wrong.
    Watching this forum for a long time it's amazing what people get up to. Exploring every possible nook and cranny of it's functionality. Looks like any oddities would have been uncovered by now.

    Of course all kinds of things can go wrong, but just now it seems highly likely that if they do it is the user/programmers fault.

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  • SapiehaSapieha Posts: 2,964
    edited 2009-12-08 11:33
    Hi faizzz


    In my intensive tests for Overckloking I RUN most program snipets on Propeller that YOU can find IN OBX and some in threads on formu.

    EVEN with frequencies that I still look if I overcome some transc ient problem´s PROPELLER worked maybe not 100% but next 99%.
    with that frequencies I had only some ustablity in Clock pulse lenghts NOT more.
    NOW I RUN very stable 120MHz (15MHz - PLLx8) more as 6 mounth on one of my MODED standars PROPELLER (Propeller Proto Board USB)

    OTHER PCB that I tested can run that frequencies are ---- Cluso99 --- TriBlade. (Some caps must be Tantalum)


    http://www.parallax.com/Store/Microcontrollers/PropellerDevelopmentBoards/tabid/514/CategoryID/73/List/0/Level/a/ProductID/509/Default.aspx?SortField=ProductName,ProductName


    with only diference if YOU look on this picture.
    Them have from PARALLAX mounted 2 extra Tantalum caps.

    CAN PARALLAX CHANGE THIS PICTURE TO MET BOARD?


    Regards
    ChJ

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    Nothing is impossible, there are only different degrees of difficulty.
    For every stupid question there is at least one intelligent answer.
    Don't guess - ask instead.
    If you don't ask you won't know.
    If your gonna construct something, make it·as simple as·possible yet as versatile as posible.


    Sapieha
  • AleAle Posts: 2,363
    edited 2009-12-08 12:42
    Sapieha:

    I also willingly overclock my props and add tantalums or >1uF ceramics near the power pins of the props. But I still have to use the 15 MHz crystal I bought. It still has no home.

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    Visit some of my articles at Propeller Wiki:
    MATH on the propeller propeller.wikispaces.com/MATH
    pPropQL: propeller.wikispaces.com/pPropQL
    pPropQL020: propeller.wikispaces.com/pPropQL020
    OMU for the pPropQL/020 propeller.wikispaces.com/OMU
  • heaterheater Posts: 3,370
    edited 2009-12-08 13:12
    I just noticed. There are no problems with the Propeller but there may be problems with the propellor [noparse]:)[/noparse]

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  • SapiehaSapieha Posts: 2,964
    edited 2009-12-08 13:23
    Hi Ale.

    If I understod correct ... Last PCB You have consrtructed wit my recomendations on XTal barier around pins.
    That must give You posibility to RUN it without problems with 120MHz and can be 3 board already to that for PROPELLER.

    I use to Overckloking 1 10nF - 2 100nF and 2 droped Tantalums betwen 10uF to 33uF ... still lock for best alternative (Some PCB´s ned biger and some not)


    NOW one very dumb question?
    I don´t have many to BUY Yours PCB (else other ones) .... But I You will give me one as XMAS present I can test it AND give You recomendations.

    Regards

    Christoffer Jönsson

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    Nothing is impossible, there are only different degrees of difficulty.
    For every stupid question there is at least one intelligent answer.
    Don't guess - ask instead.
    If you don't ask you won't know.
    If your gonna construct something, make it·as simple as·possible yet as versatile as posible.


    Sapieha
  • MagIO2MagIO2 Posts: 2,243
    edited 2009-12-08 13:24
    So far I only heard about the PLL problem, but again that's caused by wrong usage - but nevertheless a trap you could run into if you do your own board design.
    When I remember that right the problem was not attaching the power supplies properly. In this case the PLL can be damaged and you have a PROP that no longer runs with a crystal.
  • SapiehaSapieha Posts: 2,964
    edited 2009-12-08 13:31
    Hi MagIO2

    BAD usage on BREDBOARDS .... I don´t count .... That can damage most of IC´s

    AND Yes ... PLL needs very stable VOLTAGES to PROPELLER to function correctly without damage


    Regards

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Nothing is impossible, there are only different degrees of difficulty.
    For every stupid question there is at least one intelligent answer.
    Don't guess - ask instead.
    If you don't ask you won't know.
    If your gonna construct something, make it·as simple as·possible yet as versatile as posible.


    Sapieha
  • MagIO2MagIO2 Posts: 2,243
    edited 2009-12-08 13:39
    So I must be very lucky! I run my propeller on a breadboard since I started which is now 9 month ago. I attached any kind of devices to the propeller:
    nunchuck, keyboard, mouse, encoders, servos, text-lcd, graphical lcd with touchscreen, SD card, 5V shift registers, pushbuttons, LED arrays, 3 digit number displays with LEDs, VGA monitor, TV, NTSC LCD display ....... and more to come ;o)

    Never had a problem!
  • LeonLeon Posts: 7,620
    edited 2009-12-08 13:43
    The problem with using a breadboard for the Propeller is that the contacts aren't very reliable, and the PLL might be damaged if one of the supply pins gets disconnected.

    Leon

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  • SapiehaSapieha Posts: 2,964
    edited 2009-12-08 13:57
    Hi Leon


    You are Correct ..... BUT on BredBoards for that Placement of IC´s ... I use Maskine pin sockets.
    Place IC-Propeller in socket then socket in BredBoard ... That give me security to have good conntact to IC´s pins from BredBoard ... To that use wires for Voltages that have same masurements as Maskine pins IC´s holders.

    Regards

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Nothing is impossible, there are only different degrees of difficulty.
    For every stupid question there is at least one intelligent answer.
    Don't guess - ask instead.
    If you don't ask you won't know.
    If your gonna construct something, make it·as simple as·possible yet as versatile as posible.


    Sapieha
  • LeonLeon Posts: 7,620
    edited 2009-12-08 14:22
    That would make them more reliable. I never use them, though, I just make a PCB.

    Leon

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  • SapiehaSapieha Posts: 2,964
    edited 2009-12-08 14:44
    Hi Leon


    In some cases IF I know .... I will ue that IC holder to specific IC-CPU I solder all nessesary CAPS placed inside Socket botom on IC-CPU.
    Maskine pis holders give that posibility ..... And not need wories that nonthing go wrong. ... Posible to prepare that holder to have both GND and Voltage pins connected .... that give me posibility to use only 2 wires on BredBoard to connect to HOLDER ... Give no mistakes if I mis one wire ....


    Regards

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Nothing is impossible, there are only different degrees of difficulty.
    For every stupid question there is at least one intelligent answer.
    Don't guess - ask instead.
    If you don't ask you won't know.
    If your gonna construct something, make it·as simple as·possible yet as versatile as posible.


    Sapieha
  • Cluso99Cluso99 Posts: 18,069
    edited 2009-12-08 17:40
    heater: Want to offer to eat a RamBlade??? *smirk*

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    · Home of the MultiBladeProps: TriBlade,·RamBlade,·SixBlade, website
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    · Prop Tools under Development or Completed (Index)
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    · Search the Propeller forums·(uses advanced Google search)
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  • MacGeek117MacGeek117 Posts: 747
    edited 2009-12-08 18:56
    The only problems I have had on the Prop deal with servos, but it may just be a power supply issue.
    Still looking into the problem.
    MacGeek

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    Propeller Protoboard: Priceless

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  • mctriviamctrivia Posts: 3,772
    edited 2009-12-08 21:07
    Only problem I have had was it did not like when I accidently applied 12v to it.

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  • LeonLeon Posts: 7,620
    edited 2009-12-08 23:26
    They don't like 9V either.

    Leon

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    Amateur radio callsign: G1HSM
  • StefanL38StefanL38 Posts: 2,292
    edited 2009-12-09 05:33
    No hardware problems so far

    some software traps:

    Indention is critical. you HAVE TO indent code that should belong to a repeat-loop if-, or case-statement

    You can't access variables defined in the VAR-section across objects (=other *.spin-files)

    IF you start another cog with cognew you have to provide enough stackspace minimum 20 longs

    Each cog needs his OWN stackspace

    Avoid recursive calls of methods. this will quickly eat up all the memory and will make the program crash (NOT the propell-E-r)

    If you start another cog and the nethod you start it with has NO repeat-loop
    it will run the code ONCE and then stop. Just as you wrote the program to behave

    ALL other questions can be answered by uploading your COMPLETE code

    best regards

    Stefan
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