How connect UR 3.0 with serial port

[amblipijido]

Hi, i´m searching the wiring diagram to connect UR 3.0 with serial port and LDR´s but i don´t find anything, someone can show me how to connect? sorry for my english but i´m from spain and i don´t talk very well. thanks

[2FER SLOTS]

Near as I can tell there is a diagram here http://http://www.hoslotcarracing.com/LapCounter.html
Look at the hardware settings page of Ur3.0 and verify which pins to use.

[amblipijido]

Nothing, not work, in the page settings i select the pins and test it , the pins flashing but in the race no count the laps. It's impossible!!

[RichD]

The program needs to know which comm port you are connected to. I am not sure what LDRs are, but make sure that they are working properly. Sometimes the ports in your computer are not compatable and you will never get this to work.

[SlotsNZ]

I presume he means Light Dependent Resistors.

They could well be the problem Rich, as they may be moving between a low and high resistance with the changes in light he is creating, but not going completely open circuit/closed circuit.

Failing that, the comm port may be wrong, but it sounds more like he can get a signal by shorting, or even by blanking out in test . . so the LDRs are the more likely culprit.

amblipijido - You would be better off using a decent photo-transistor. Preferably one that is described as a "darlington pair" (that really means two transistors in one, doing a sort of push-pull thing (like two rowers on one set of oars in a boat) to get more "ooomph"
I have heard of other folk who struggled to get LDRs to work reliably. - maybe just because they were not ideal for the degeee of light change being evident in their situation.

I have made so many leads up that way for timing I lost count. They almost never fail, I can only remember ever replacing one.

Couple with a compatible light source you will get 100% perfect lap counting.