HSERIN HSEROUT 9BIT & PARITY (Output is Losing a bit!)

[HenrikOlsson]

The receiving device is now accepting the input but Saleae logic still shows errors in the data the PIC is outputting???
Something weird is going on..

If you still have the protocol decoder set to 9E1 then I believe that would be the problem since the output from the PIC is 8E1 (11bits total). Likely the input is 8E1 as well, don't you think?

[retepsnikrep]

Yes but setting the decoder to 8E1 on the input gives parity errors. ???

Attached is some logic 1.2.40 data. The top line is the incoming data.

Perhaps some kind soul could have a look at it and see what they make of it.
Have I got the baud rate/parity etc right for the incoming data decoder?
I've tried loads of variations!!

The shortest pulse is about 20us

Note the output data is now at least the same length as the input and the receiving device seems to accept it, but the output decoder with the same settings as the input gives errors!!!

LogicData.zip

[tumbleweed]

If you set both channels of the protocol decoders to 8 data bits, odd parity, 1 stop then the errors go away (8O1), but I don't know about the data.

Are you sure about the format? You don't include the parity bit in the count of data bits. Typical formats would be 8N1, 8E1, or 8O1.
Normally, in 9-bit mode there's no parity used (9N1).

[HenrikOlsson]

Yeah, like tumbleweed says, it does seem to be ODD parity, not EVEN.

[retepsnikrep]

I think you are both right. Thanks a lot.
I had tried lots of combos!!! But missed odd parity...

[retepsnikrep]

Attached is another Saelea logic data file in which I am struggling to work out the baud rate and parity etc.
It's from a similar device to my earlier posts in this thread so logically you would think format etc would be similar.

The shortest pulse/bit is about 19.30us so that equates to about 51813bps

But that doesn't work in the analyser unless I am missing something.

Only 55000 8, E,1 seems to decode without errors??
But I'm not convinced that is correct.

If I then program my PIC with that baud rate etc it returns garbage or misses the data entirely.
I've even tried using osctune to shift the PIC baud rate up and down but no joy yet.

I'm tempted to try autobaud but that looks pretty tricky from the PIC16F886 datasheet.

What do members think the data rate/parity is of the attached file?

[tumbleweed]

48000, 8o1 seems to work