Can a pic do several things at once?

[Acetronics2]

Hi, Karen

You seem tired ... and should rest some little time.

I was just explainng you HOW and WHY your different things could be done by the same Pic ...
By the way, add the regulating calculations to the duties the Pic will have to do ...

Will you use PID or Fuzzy to drive your Solenoïd ???

a little question :

This Doppler shift is directly
proportional to velocity of the receiver along
the direction to the satellite, regardless of the
distance to this satellite.

Must I think from that it can't work in a deep forest, a narrow mountain valley, or between high buidings, ???

Alain

PS: That's you who talked about "blondes" at first ... not me !

[karenhornby]

Hi, Karen

You seem tired ... and should rest some little time.

I was just explainng you HOW and WHY your different things could be done by the same Pic ...
By the way, add the regulating calculations to the duties the Pic will have to do ...

Will you use PID or Fuzzy to drive your Solenoïd ???

a little question :



Must I think from that it can't work in a deep forest, a narrow mountain valley, or between high buidings, ???

Alain

PS: That's you who talked about "blondes" at first ... not me !

LOL
thanks everyone
The need for 100% accuracy 24/7 isnt essential, I was actually thinking of having the display so I can see when I'm getting near the speed limit the cops WILL ticket me
and
Its mainly going to be there as a backup to the actual speedo (they have been known to break) and the other reason.. is the reason someone (wish I could remember who) when asked why he did something said:
because I can.
I just thought it would be a good way of learning how several part of the pic work, how to program the various bits, see it working everytime I drive, and more important,. anytime anyone asks about it I can not only say waht it was, but also say "I did it"
yes.. I admit i'll like boasting once its finished

[enauman]

If you are interested in accuracy, don't forget that most commercial GPS units don't display instantaneous velocity. Most of them average over a 5 second window. That is to say that what you see on the screen is the averave velocity of the last 5 seconds. The fastest it can update is once per second. If you really want accuracy and readability, make a speed pickup from a magnetic or optic sensor and put it on the drive shaft as was suggested. Then write the code to read it, translate it, and display it. If you want to split hairs, calibrate it through the operable speed range to compensate for tire expansion.

This is not PIC related, but it is an example of what can be done with a GPS head.
A while back the radio guy at work was walking all over the plant with a signal strength meter trying to map blind spots in our radio coverage. It was going to take him a month to get a minimal amount of data. I bought a Garmin GPS head with an RS232 output and fed it into the serial port on a laptop. I routed the signal strength output from one of the hand held radios into a DAQ board in the PCM-CIA slot and wrote some labview code. All he had to do was put the laptop, GPS head and radio into a car and drive around the plant. The code sampled position and signal strength and plotted a colored representation of the signal field overlaid on a map of the plant property. It took about 3 days to put it together and write the code and about 30 min for him to collect all the data needed. If you really want to interface the GPS with the PIC, I suggest you use a 16F876 and get a GPS head with an RS232 output. The NEMA format is real easy to handle.

Edward A. Nauman
Senior Staff Engineer

Lockheed Martin Aeronautics
"The Skunk Works"
Mail Stop 0157
1011 Lockheed Way
Palmdale, CA 93599
Voice: (661) 572-7350
Fax: (661) 572-3507
Cell: (661) 305 7636