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Sterling
04-25-2006, 12:49 AM
I've seen conflicting information about baud limits. What is the max serial out baud rate a BS2 can handle?

Chris Savage
04-25-2006, 12:54 AM
That's a loaded question. The limits of communication and the limits of sustained throughput are two different things with a BASIC Stamp which doesn't have a FIFO buffer or hardware UART. Formatters used in the SERIN command can also limit receive speed of large packets of data. This would be like sending command bytes and getting back small packet responses. So you see, there are many factors to consider. Generally the BS2 can do 38.4Kbps for general command byte style communication. ASCII strings and packets of data work usually up to around 9600 bps if you're not using a lot of formatters in the SERIN command.


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Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

Sterling
04-25-2006, 01:19 AM
Would 4800bps be the more reliable number if I want to ensure the data is sent? I suppose the lower the number, the more reliability I have?

Jon Williams
04-25-2006, 01:59 AM
The BS2 can transmit (SEROUT) up to about 50K baud (SERIN has limits if you want text-to-numeric conversion) -- if you have a good connection between point A and point B. If you connection is garbage, a lower baud rate will be more forgiving; that said, ALWAYS make the best connections you can (don't try to fix hardware problems with software).

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Jon Williams
Applications Engineer, Parallax

allanlane5
04-25-2006, 02:01 AM
9600 generally works well enough. Yes, the lower the number the longer a wire you can support.