MAGracing Forum

Thanks for the photos, Wes. It's a neat idea to have everything in a hole in the track like that.

WesR wrote:This counter seems to work well with only the single sensor per lane

Just to make sure I understand this correctly: does this mean there is only one photo transistor for each lane?
My experiments suggests that one should be enough, even at fairly high speeds. But it would be nice to get confirmation.

WesR wrote:If you really need to know more technical info, let me know exactly what and I will try to find out.

No worries. I do have a fully working sensor setup that is stable. I just need to figure out the last details about how best to get everything mounted on the track.

I would like to know the protocols for the transmitter and receiver,,,,

Steellynx, yes, just one sensor/photo transistor whatever.
Joel, I will try to get this info.

Hi.
Found this today :
http://www.racecoordinator.net (And it all free )

It is supposed to have Arduino interface right out of the box.
Hopefully I will be able to use your experience to make an interface/sensor for it.) Sometime in 2016.

Please verify !

Have been trying your circuit without luck.

You specify : PNP transistor (BC547)

I have used BC547, but can only find it being a type NPN. (And not being able to find a PNP BC547 to buy either.)

Anyone else got it working ?

kiklo wrote:You specify : PNP transistor (BC547)

That's because I'm a nitwit
I did use BC547s but as you correctly say they're NPN. Sorry about that!

If you're having problems it might be an idea to do a more simple test to check that the light sensors work and can activate the ports on the Arduino. Maybe just a simple program that lights an LED if light hits the sensor.

I'd love to write such a test for you but will not have time for at least a few days. In the mean time here is (for reference) a photo of my test setup that works.

Thx for the photo. I'll work my way trough it tonight.

Sounds good. Please note that the photo does not show the IR photo transistors but only the "right half" of the schematic posted earlier in this thread.

One simple test would be to disregard the Arduino at first and simply connect an LED where it says "To Arduino PINx". That LED should be on or off depending on whether the IR photo transistors "sees" IR light (can be simulated with an IR LED)

Thx. that should help a lot !

And just to make sure I'm on the right track :
Your output (video) on the screen that would be the "Arduino serial Monitor ?"

kiklo wrote:Your output (video) on the screen that would be the "Arduino serial Monitor ?"

I actually think that's the program PuTTY, that can (among other things) dump the data received on a serial port. If there's a serial monitor with your other development tools then that should work equally well