BS2p24 and Baud Rate

Harry Stoner · 2004-07-23 15:20

I bought a couple of the "scratch and dent" BS2p24 stamps from Parallax. Hope to use one in place of an existing BS2 for faster serial I/O. Currently I can do reliable I/O at 2400 baud. The BS2p is about 3X faster, so would that correspond to 7200 baud (or say 4800)? Seems like a simple obvious question but maybe it's not.

I will be putting together a new breadboard for this on the weekend (if I have all the components I need on hand) so should be able to start testing this soon.

Thanks.

Harry

Jon Williams · 2004-07-23 15:28

If you don't change your code then you may have a problem as the BS2p is indeed faster. I trust that you have our latest compiler (2.1). It allows conditional compilation which simplifies parametric changes for different BASIC Stamp modules. Here's a bit of code I use for serial programs:

#SELECT $STAMP
· #CASE BS2, BS2E, BS2PE
··· T1200· CON· 813
··· T2400· CON· 396
··· T4800· CON· 188
··· T9600· CON· 84
··· T19K2· CON· 32
··· T38K4· CON· 6
· #CASE BS2SX, BS2P
··· T1200· CON· 2063
··· T2400· CON· 1021
··· T4800· CON· 500
··· T9600· CON· 240
··· T19K2· CON· 110
··· T38K4· CON· 45
#ENDSELECT

Inverted·· CON· $4000
Open······ CON· $8000

Baud······ CON· T2400

This lets me change modules without worrying about changing the SERIN and/or SEROUT baudmode parameter.

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Jon Williams
Applications Engineer, Parallax
Dallas Office

Harry Stoner · 2004-07-23 15:38

Thanks Jon. I downloaded the conditional compilation examples yesterday and will indeed use them. I will also add conditional statements for the pulsout times (if I recall the units are different for different Stamp models).

It would be a nice PBASIC future feature (say that out loud quickly 5 times) to have C-style includes for stuff like this to make the code more readable. E.g. #INCLUDE StampDIffs.bs2 or something similar.

Doesn't affect anything executable so hopefully would be do-able.

Thanks.

Harry

BS2p24 and Baud Rate

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