question about stamp for quadcrawler
joe from NY
Posts: 22
Hi, Been interested in building a robot kit. I think i will purchase a Quad crawler kit.
I see it comes with the BS2 stamp chip.
My question (after comparing PIC vs Stamps vs OOPIC) is this controller powerful enough for this robot·leaving ·room for expansion? (arms, speech ,etc)
I am asking this as I understand the basic stamp does not have interupts. Does this lack of interupts cause problems with programming robots of this size??
Please enlighten me on this subject [noparse]:)[/noparse]
·
I see it comes with the BS2 stamp chip.
My question (after comparing PIC vs Stamps vs OOPIC) is this controller powerful enough for this robot·leaving ·room for expansion? (arms, speech ,etc)
I am asking this as I understand the basic stamp does not have interupts. Does this lack of interupts cause problems with programming robots of this size??
Please enlighten me on this subject [noparse]:)[/noparse]
·
Comments
The BS2 cycles at about 2000 Basic Instructions Per Second. This is MUCH faster than people think. This is MUCH slower than most microprocessors (a typical PIC has a 20 Mhz clock, but takes 4 clock cycles to do anything, so cycles at 5 MIPS -- however, these are PIC assembly instruction MIPS, not full Basic instructions).
A PIC only has one level of interrupt, so its interrupt useage is problematic to begin with.
The BS2 is a single-tasking processor, so when it is 'listening' on a SERIN instruction, it can't drive the wheels. However, using Airplane Servo's, you refresh the servo position signal every 20 mSec, so you CAN drive multiple servo's in a program loop. In other words, there are very effective work-arounds for this single-tasking nature.
The BS2 only has 26 bytes of RAM, but 2000 bytes of EEPROM. This can be a limitation.
Conclusion: People usually start out using the BS2, because it is extremely reliable, requires little battery power, and is extremely easy to program for proof-of-concept devices. If they run out of 'horse-power', they've at least proved out the hardware, and can transition to more native PIC solutions. Note these "native PIC solutions" usually have a much more expensive development system, but can be cheaper for many copies.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com
Post Edited (Chris Savage (Parallax)) : 12/15/2005 3:24:56 PM GMT
I guess if the quad crawler is sold with the bs2, it must suffice for such a kit.
Anyone here build a QUADCRAWLER?>
·· To clarify my previous post (Which was mis-interpreted), all of our software and documentation is freely available on our website.· It so happens that programming the SX requires one piece of additional hardware (The SX-Key), which obviously isn't free.· I apologize for any misunderstanding that may have caused.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com