View Full Version : What is fastest "high level language" processor from Parallax?

11-23-2006, 02:49 PM
Currently, I just received my BS2·Prof Dev kit so I can learn to control things with a chip.· Pretty cool!· Learning alot.

My·short term goal is to process analog data sampling at 12,000 times a second.· This will be engine data for racing.· It will deliver it's "report" to the master CPU about 4 times a second.

What would be the fastest Parallax option?· I can do assembler if I have to, but would rather avoid it.·

Kevin Wood
11-23-2006, 06:49 PM
The fastest chips would be the SX and Propeller.

The SX can hit 75MIPS and can be programmed in Basic, which gets compiled to assembly.

The Propeller uses Spin, which I think will do ~20MIPS per cog, with 8 cogs. Actually, I think the 20MIPS is with ASM, since the Prop will run at 80MHz, with 4 cycles per instruction. The SX ratio is 1:1.

11-23-2006, 10:00 PM
Thanks! Sounds like the SX will have more than enough speed to git-er-dun. Guess I should start reading on the SX. Still trying to get my hands on a pressure sensor that will have a fast reaction time and read up to 400 bar (~6000 PSI).

Steve Joblin
11-23-2006, 10:35 PM
If all you need is 12,000 instructions per second, I think the BS2p24 or BS2px both meet this requirement!

11-23-2006, 11:18 PM
Not sure how many actual instructions per second will be required to process the sensor data. Perhaps 20 per sampling? So maybe 12,000 * 20 instructions per second.

First I will use the BS2 to get a feel for how to even start such an endeavor (me and electricity are sworn enemies, but we have called a temporary cease-fire for the holidays), but I will want "overkill" for the processor speed for debugging and expansion.

And I'll try to incorporate more functionality into the system as time goes on. For now, I just want cylinder pressure readings ever 2 deg of crank rotation, calculate an average, and a peak, and send a packet of info out to my existing engine programming datalogger to tie it into "normal" engine data. Peak pressures occur at 2100-2500 engine RPM and here is where we are breaking very expensive engines. These are digitally-controlled turbo-diesel engines running about 750HP. Very high combustion pressures.

11-24-2006, 12:12 AM
The Propeller does 80K Instructions/Second for each COG in Spin, so should leave a lot of 'excess' cycles for anything you'd like. Maybe stick a SD-card there and store a copy of the sensor data? Or add a few more sensors?

Don't visit my new website...

11-24-2006, 04:34 AM
Yes, something like the Propeller would be wicked to do actual closed loop engine control, and store the calibrated data tables on a SD card. But to look at just one stream to find the peak, more speed is more better.

But... baby steps. Baby steps! I can finally control LED's with the BS2 and have not burned down the house and still have all 10 fingers. Apparently my luck is good! Time for a trip to Vegas. :D

I will order some SX stuff next week.