A friend of mine sent me an inquiry about something that's a bit over my head (at the moment), so I'm forwarding his mail to this list to see if anyone here has any pointers where I could start dig and help him out. -------[cut]---------- Let me tell you what i am trying to do: The idea is that we have 2 laser beams that will form together a radar system that will calculate a car's speed. A car will be travelling down a road and 2 laser beams will be in front of the car. The PIC should start counting when the car passes through the first laser and should stop counting at the time the car passes through the 2nd one. We will do the circuits with the lasers, so for the programming issue we can assume that we have 2 pins (2 inputs) that will have the 2 laser beams connected. So when PORTA goes to 1 logic we should start counting and when PORTB goes to 1 we should stop couting the time. Then , knowing the time and the distance between the 2 lasers, we can calculate the car's speed. In theory it is just a clock but it needs to be able to count time very accurately. We were thinking to add an external clock to make it more sensitive. We need to be able to count down to 0.0001 sec. The speed should be multiplexed and diplay on an LCD display with 1 or 2 decimals - 52.3(2) km/h This is all :) We don't really need to use an 18FXXX but someone suggested that those have USB ports (?!?) and we can then connect it to a laptop and enhance the app with a Visual Basic interface. However, the main goal for me at this point is to learn to do a project or two with those so that i can get started... So i am interested in someone that can make this project and explain it to me. It doesn't really matter how it is done, but i would like to be able to see it working in some simulations or to be able to have some schematics for it. This is why i tried using MPLAB because it seems to be the most complex app out there. -------[cut]---------- -- - Rikard - http://bos.hack.org/cv/ -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist