I made the photovore sensors the same way as the Admin did. But i had a different result. They are not sensitive. They only work in the dark with a strong, bright flashlight.
As I was doing the formula, my resistance in the light of my room was about 10k (using the sensor at its side since it will be like that on the robot) then under my bed in the shadow (since i want it to avoid that) was about 100k. I did the formula and I got about 30k Ohm resistor I should use. Now this is way off from the Admin's sensor value.
I was wondering if I should replace my 1.5k resistor with a 30k resistor to see if it works better? Is there something I am doing wrong?
P.S. My multimeter is accurate since I measure other resistors with the correct value. So it is not my multimeter that is wrong.