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Baud Rate
Posted: Fri Mar 09, 2012 4:22 pm
by christoph
Hi Matrix,
I have set a Baud rate in flowcode of 9600 (because the wireless system I am using transmits and receives UART at that rate) but my 'SCANALOGIC 2' logic analyser is telling me the Baud rate is actually 230400 which is 5 standard board rates out.
Sorry, but could I get an answer on this one pre-weekend - why the huge difference? Probably something I don't understand but your help would be gratefully received.
Regards,
Chris
P.S. The flowcharts are the ones posted on my 'failure code =1' posting
Re: Baud Rate
Posted: Fri Mar 09, 2012 5:17 pm
by Benj
Hi Chris,
I see you are using the internal oscillator set at 4MHz in your program and also that your clock speed is setup correctly in the project options.
Could you try performing a 1 second flasher test just as a sanity check to ensure that the hardware is running at 4MHz.
Maybe worth flicking the oscillator switch on the EB006 to RC if you are using this board to ensure that the crystal is not being used. If your using a v7 EB006 then you can move the oscillator jumper from the OSC to the I/O setting to disconnect the on-board crystal.
Also in your program you are receiving data. For the baud rate to be shown you need to be transmitting data. Is your program to do this setup any differently to the receiver program you posted?
Re: Baud Rate
Posted: Fri Mar 09, 2012 5:52 pm
by christoph
Hi Ben,
Actually I'm not using any e-blocks. Also the whole set-up transmits and receives perfectly well (except I need 12 ways which I cannot for the life of me get to work). I just wanted to make sure with the logger that I WAS actually at approx. 9600 baud and was expecting a bit of leeway but this much is a bit puzzling. As someone who is new to all this I was wondering how much of a mismatch between the manufacturers wireless UART at 9600 baud and the chip selected UART speed can be tolerated. Same question with the e-blocks I guess?
Regards,
Chris
Re: Baud Rate
Posted: Fri Mar 09, 2012 6:09 pm
by medelec35
christoph wrote:except I need 12 ways which I cannot for the life of me get to work
I can't guarantee I can do this, but I will give it a go and see if I can get it to work.
Martin
Re: Baud Rate
Posted: Fri Mar 09, 2012 7:07 pm
by christoph
Hi Martin,
OK thanks - I really appreciate that - I thought it would be easy but have tried everything I can think of (in my rather inexperienced way).
Fingers crossed but I understand if it 'wont go'.
Chris
Re: Baud Rate
Posted: Sun Mar 11, 2012 9:30 pm
by medelec35
I have posted a set of flowcharts here:
http://www.matrixmultimedia.com/mmforum ... 380#p33429
Can you let me know how you get on please.
Martin
Re: Baud Rate
Posted: Sun Mar 11, 2012 11:50 pm
by christoph
Hi Martin - much obliged. Have just got back and will check them out now.....
Rgards,
Chris
Re: Baud Rate
Posted: Mon Mar 12, 2012 12:58 am
by christoph
Martin,
I have naturally carried on the posting where you placed the flowcharts now
Chris