UART Decoding producing wrong result after off-on?

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egerg
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UART Decoding producing wrong result after off-on?

Post by egerg »

Hi,
I'm wonder about a strange behaviour: during the initial off-on trannsition of my uart, the serial decode shows a received byte Oxff; I can make this go away when I change the threshold in the decoding dialog from 2V to say 2.7V in this 3.3V system. Is this a bug, or am I missing thomething?

The waveform ist attached.
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UART-Error.psdata
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Martyn
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Re: UART Decoding producing wrong result after off-on?

Post by Martyn »

If you change the hysteresis setting for the decoder to 100mV you will see this rogue packet disappear.

It is being created by detecting noise on the edge as a start bit, and is related to a bug we have with start bits not being validated for length. This start bit length issue has been fixed and will be available in the next release of the software.
Martyn
Technical Support Manager

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