View Full Version : Looking for on off specifiations
11-13-2009, 04:07 AM
Thanks in advance for all your help!
I am trying to determine if the Basic Stamp will meet my needs.
I need to know what the specification is for rise/fall and on time is (minium).
So if I send a pulse on command and then a pulse off command what will be the rise/fall and on time for the different stamps?
11-13-2009, 04:34 AM
All of the Stamps except for the BS2 use an SX processor which is sold by Parallax and the datasheet for that processor would give the rise and fall times for the I/O ports. The BS2 uses a Microchip PIC16F57. That datasheet is available from Microchip's website and would give the rise and fall times for that processor's I/O ports.
The minimum on time would vary from processor model to processor model and depends partly on the Stamp interpreter and its overhead. The PULSOUT statement is probably the best way to get a well controlled short pulse and the resolution of that statement depends on the Stamp model. The STAMP Basic Syntax and Reference Manual and the Stamp Editor help files give the units used by the various processors. For the BS2, it's 2us. For most other Stamp models, it's 0.8us. There's also the overhead for the PULSOUT statement and other statements that would set a repetition rate limit. These are discussed on Tracy Allan's website www.emesystems.com (http://www.emesystems.com) by following the "app-notes" link at the bottom of the page.
11-13-2009, 05:39 AM
Thanks Mike for the good information!