hi,

i can not understand how moving ball will change its frequency. if its due to dopler effect, it wont, as far as my knowledge is concern.

most IR eye units are available used in TV remotes. it has three pins. one of them is ground another is +ve suppy(5 V through a 100 ohms resistor) and thir is signal out.
if you light a IR LED continuously in front of it out put remains a supply voltage, pulsate the LED and you will get a pulse out of output pin. for more details see the data sheets.


abhishek