| Author | beginning argument ( Replies received: 6 ) |
| ivan1 |
Posted 01-09-2008 at 11:50   |

Registered on : 08-28-2008
Messages : 4
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Hi All,
Now I want to send some data through USART 3 every 10ms.
So I use RTX in my project, and use os_dly_wait method or os_itv_set&os_itv_wait method to make it work.
But It's not working as I thought.
The interval time is not 10ms every time, even not the same value.
What's wrong with that?
How to realize what I want?
Thank you.
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| jj.sprague |
Posted 01-09-2008 at 16:31   |

Registered on : 02-28-2008
Messages : 180
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Hi Ivan,
Can you temporarily shift to USART 1 OR 2? In so doing we will learn if your problem is restricted to USART 3 - or if it is one of set-up or implementation.
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| ivan1 |
Posted 02-09-2008 at 08:03   |

Registered on : 08-28-2008
Messages : 4
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Hi jj.sprague
Do you mean that USART 3 is different from 1\2 in useage and performance?
I cann't to do that test.
Thank you
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| jj.sprague |
Posted 02-09-2008 at 16:28   |

Registered on : 02-28-2008
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USART3 - depends upon the device - in some cases USART3 requires "special handling."
How much does your desired interval time vary from 10mS?
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| Mikhail_S |
Posted 02-09-2008 at 21:12   |

Registered on : 07-27-2007
Messages : 3
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Ivan1,
can you toggle I/O pin instead out to USART3? What is deviation? And what you expect?
Mikhail
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| ivan1 |
Posted 03-09-2008 at 03:56   |

Registered on : 08-28-2008
Messages : 4
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On 02-09-2008 at 16:28, Anonymous wrote:
USART3 - depends upon the device - in some cases USART3 requires "special handling."
How much does your desired interval time vary from 10mS?
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What's the "special handling." USART3 requires?
I desired exactly 10ms interval time.
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| jj.sprague |
Posted 03-09-2008 at 05:12   |

Registered on : 02-28-2008
Messages : 180
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I like Mikhail's idea - toggle an I/O pin instead of transferring over UART3. This will confirm if your variation is caused by the USART or by your procedures which invoke it.
Please tell us "how much" variation you are experiencing...
Depending upon the device and package size USART3 may be an alternate function - which requires special set-up.
[ This message was edited by: jj.sprague on 03-09-2008 05:14 ]
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