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Wrong bit ordering in UART analyzer #122

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ghost opened this Issue Oct 25, 2012 · 4 comments

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@ghost

ghost commented Oct 25, 2012

See:
http://s12.postimage.org/4aoq2tfrx/uart_bug.png

Thre front byte bits are reversed, it should recognize 0b10101100 afaik

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jawi commented Oct 25, 2012

From the image I cannot directly deduce what the supposed results should be; do you have a capture file for me to verify this?

@ghost

ghost commented Oct 25, 2012

Hey,

sorry, didn’t keep the testcase.. However, you can see it well on the image: the bits are sent LSB first, so “00110101”, now append start and stop bits: 0001101011.Thre first symbol is going almost exactly till the falling edge under the second time marker line. Divide it imaginary into 10 same length parts and you see it’s sent correctly.

Tell me if it helps – if not, I’ll reprogram my testboard and do the record once I have time.

PS having the “exact” baudrate is soo great about the analyzer, helped me a lot!

From: Jan Willem Janssen [mailto:notifications@github.com]
Sent: Thursday, October 25, 2012 10:19 AM
To: jawi/ols
Cc: Maverick89
Subject: Re: [ols] Wrong bit ordering in UART analyzer (#122)

From the image I cannot directly deduce what the supposed results should be; do you have a capture file for me to verify this?


Reply to this email directly or view it on GitHub #122 (comment) .

https://github.com/notifications/beacon/jeO1xPSnkeVf8skM755V4d_J1utDhj5Zx4ZBQYdJcmXbVpfZ3HzBzuuqgyeEo2vp.gif

Owner

jawi commented Oct 25, 2012

With your explanation it indeed seems a problem in the decoder. However, I'd like to verify this against "real" data in order to find the actual bug. So, if it wouldn't be much trouble, could you still provide me a capture file? I'd also like to add this file to the test cases of the decoder to keep this problem from reappearing in the future, is that ok with you?

Contributor

matthijskooijman commented May 27, 2013

Scratch my last comment, bits are transmitted LSB first normally (I probably misremembered...)

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