Ir sensor AGAIN

I gave up the idea of the pna4602m as it was getting me nowhere! i decided to try this http://www.societyofrobots.com/schematics_infraredemitdet.shtml AGAIN and used the simple circuit and got some results. the only thing is, i could only get the range up to 8cm - 10cm. Is there anyway to increase the distance of detection?

Modulate it. (Turn it off

Modulate it. (Turn it off and on very fast and measure the difference).

Or use Op Amp if the signal is too weak.

And read: https://www.robotshop.com/letsmakerobots/node/2907

 

And maybe: read book on http://web.zone.ee/robostuff/1.pdf

op amp

possible without an op-amp? i put a "casing" for the ir led and i was able to get 15cm, but i dont think that is great enought for a mini-sumo as the ring

diameter is 77cm.

able to get 25 cm now! the
able to get 25 cm now! the only problem is inteference with lighting. any ideas?