Re: [Flashforth-devel] strange answer from UART

[Herman A. <exp...@vn...>]

Hi Thomas,

Maybe your problem comes from low Osc-frequency/baudrate ratio. Using 4MHz osc freq. the controller generates the 38400kbs with 10% error. Try to use higher osc freq. or lower baudrate. Otherwise I recommend you to use 18F26K22 or other xxk22 controllers. They have well configurable internal oscillator and have several further excellent features.

BR
Attila

----- Eredeti üzenet -----
Feladó: Thomas Buschhardt <bus...@gm...>
Dátum: Hétfő, Március 17, 2014 8:32
Tárgy: [Flashforth-devel] strange answer from UART
Címzett: Fla...@li...


> Dear Mikael and mailing listeners,
> 
> I desperated, I got some strange signs back from the PIC. In my 
> despair - I
> installed even MS Windows, to see whether my usb-2-serial adapter is broken
> - but the program "Hyperterminal" shows the same results.
> 
> Here is my configuration:
> 
> PIC18F2620
> 4 MHz Oscillator Link to
> Oszillator<>
> MAX232
> FD-USB2Serial-Adapter
> 
> The programing - process runs well with my PICKIT2. When the PIC gets 
> power
> its send the same strange signs, and if I blind input "1 2 3" (to the
> stack) in the terminal, I got a answer - that could be the right one.
> --snip--
> 38400 -  8 - N - 1
> ¦¬¡³¸¦¯²´¨ •Ž° °©£±˜ Š Š‘
> ¦¬¡³¸¦¯²´¨ •Ž° °©£±˜ Š Š‘
> ¦¬¡³¨¦¯²´¸ •Ž° °©£‘¸ Š Š‘
> ± ² ³ ± ² ³ Ÿ Š
> --snip--
> Here I restart 3 times the PIC and input "1 2 3" and get back "± ² ³ Ÿ 
> Š".
> 
> I changed the baudrate, oszillator frequency, the oscillator selection 
> bits
> - without success.
> I hope I do some configuration mistakes, so please help me.
> 
> The schematics for my hw-configuration, the (binary) log-file of the
> terminal and my changed configurations-files you can find here as zip 
> file.
> 
> 
> 
> 
> If you need more informations, please drop me a mail.
> 
> Greetings Thomas
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