Possible Configuration to keep things cheap

[archiver]

Posted by Rick Berube, Engineer on team #121, Rhode Warriors, from Middletown H.S..

Posted on 5/23/99 8:20 PM MST


In Reply to: Possible Configuration to keep things cheap posted by Thomas A. Frank on 5/23/99 11:11 AM MST:



Certainly some powerful hardware, but what about the software development environment? After all, that's really what we're talking about here right? More processing power, multi-tasking, networking, timers and interrupts. Its all just a bag of buzz words without the software support required to tap into it.

One thing I think we're all taking for granted here is the simplistic development environment that the Basic Stamp provided. I submit that such ease for software development is still required. Six weeks remember! How many of you software types had access to the hardware throughout the six weeks? Early in the six weeks? Let's face it, the software will always be one of the last things completed on your 'bot unless you used the default program. 'Bit-heads' want to be able to leverage a set of tested and reliable rtns not re-invent the wheel at crunch time. Even teams with veteran software support do not want to start from ground zero given this schedule (don't take my word for it, ask them!).

Consider NetMedia Inc and their BasicX products (http://www.basicx.com). If any of you opened the free issue of the robotic magazine supplied in Florida, you may recognize the name. They offer much of what is being asked for here. More speed (this RISC processor provide 16-30 times the processing power of the Stamp chip (@ 7.37 Mhz no less!), multi-tasking, interrupts, RTC, timers, semaphores, floating pt. math (hey, negative numbers too!), EEPROM (SPI)support, networking support, pin I/O. And BasicX's Basic, was modeled after Microsoft's Visual Basic. They also provide a very similar PC based development environment we rely upon today for the Basic Stamp.

Joe here's an excerpt for you: 'Tasks are timeshared on a first-come first-served basis, except for tasks triggered by hardware interrupts. All tasks have the same priority, although if a task is critically important, it can be locked (see procedure LockTask), which means the task itself can decide when to relinquish control of the processor. Under normal conditions, tasks are switched every clock tick. The tick frequency is 512 Hz, which means that if you had 16 tasks all running in an infinite loop, each task would run 32 times a second. Well-designed and cooperating tasks pass on their extra processing time to other tasks if they're in a loop waiting for data or events.'

Don't expect to get anywhere near 10Mbs with RF ethernet either. If you assume 4-5 Mbs as a reasonable number, {5Mbs/12 robots ~ 400 Kbs/robot}, more than enough! With some glue-logic (FPGA?) to interface the BasicX high-speed serial interface (400-500Kb) to a PCMCIA interface, I'm sure we could realize the inexpensive network support we all want.

Thoughts? Comments?