1/ 100th second Slot car Timer

[skimask]

Thank you for your answer I see I have a lot more work to do before I hammer out the details. I will post this when I get it going. As always I can't believe the speed and quality of help in this forum. Thanks again
Snap

You know, with a PIC, an LCD, a couple of push buttons, and a few IR LEDs and IR detectors, you can easily make a slot car track timer and wouldn't even need a PC. There's probably enough on chip eeprom to store several races (if that's one of your goals), then you could download the data to a PC later on thru a serial port.

[Melanie]

Do a search on the forum for Olympic Timer.

[Snap]

I did download your program and greatly apreciate the code but I would like to have it on the PC so I can show it on a projector and play with things like sound and pictures as well as generate an excel spread sheet. I have set up the light tripping start and got it working great I just have to do the homework and see how I can feed information to the PC and have it update every 1/100 th of a second. I will post the code for both when I get it right.
Thanks
Snap

[skimask]

I did download your program and greatly apreciate the code but I would like to have it on the PC so I can show it on a projector and play with things like sound and pictures as well as generate an excel spread sheet. I have set up the light tripping start and got it working great I just have to do the homework and see how I can feed information to the PC and have it update every 1/100 th of a second. I will post the code for both when I get it right.
Thanks
Snap

Do you really need it to update back to the PC every .01 second?
You'd figure a packet with the last second's information dumped once per second would do the trick. Or I don't really understand 'what' you want to display on the projector. Is it like a 'scoreboard' so others can see it easier?

[Snap]

Yes the projector is for the rest of the racers to see. It will display the real time race times and laps for each lane. There are a few programs out there that simply rely on the printer port for a on or off switch set up with light detectors and a bank of light over them, But the windows timers are not very accurate as far as timing go's. I am just trying to do this myself to see if I can improve on it. I need to time 2 cars and need a way of manually stopping the timers when there is a crash. I am just starting and will work these details out on my own I just needed a starting point. Should the 1/100th second timing be done on the pic and sent to the PC or should the pic only send a signal that the light has been tripped and do the timing in windows. VB does have a few different ways of timing so maybe one of them is better. If the pic and serial port can handle a real time 1/100th second update I will use it for timing if not I will only use it to start the windows timer.

[mister_e]

Any windows will be accurate as long as you can do software calibration... not much.

But the PC interface is a pretty nice option... on the other hand... it may need calibration as well...

[skimask]

Yes the projector is for the rest of the racers to see. It will display the real time race times and laps for each lane.

What I mean is...the spectators aren't going to be able to see the difference between updates every 1/100 of a second or 1/10 of a second anyways, so why not slow the updates down a bit. Let the PIC keep track of actual times down to whatever resolution you want, but only send them to the PC every 1/4 second or so.

I need to time 2 cars and need a way of manually stopping the timers when there is a crash.

Is the timer stopper also going to cut power to the track? (I'm assuming these are the powered type slot cars)

If the pic and serial port can handle a real time 1/100th second update I will use it for timing if not I will only use it to start the windows timer.

With the way Windows software and PC hardware is set up these days, an input from a PC's serial port would probably be buffered in some fashion, and due to Windows multi-tasking capabilities, quite possibly might not get acted upon for a number of milli-seconds (or seconds on a slow machine ). Therefore, I think the best way to do it would be to keep track of absolute time at the track with a PIC, and send off those elapsed times/lap times/etc to the PC once in awhile...whatever the PIC/PC combo can handle. But again, I wouldn't think it would have to be that fast. After all, wouldn't people be watching the actual race, and not a big ol' TV screen?

[KeithH]

I'm pretty new to this, though I do remember reading somewhere that if you run the Chip at 4Mhz, 9600 baud is just that but if you run the pic at a higher rate, the 9600 baud setting is also multiplied. so you could get the equivelant of 24000baud if you run the chip at 10Mhz?
Sorry if I am wrong.