I need to get more distance from CNY70 to the object (my hand). I have changed 47k resistor to 200k and I get about 1 cm distance. Is it possible to get about 7 cm from CNY70 or is there any other similar sensor to achieve this?
I am not using this sensor to follow a black line but put my hand over the sensor and get "high" or "low" values.
don't know if you still have your problem? bur i know a solution.
use a 82 ohms resistor for the led.
you will get 44mA current trought your led 50mA is max
and use a 100K resistor for your reciever.
and use white reflection thing.
You can get longer response range from other sensors, but they are a good
deal larger in size. The usable sensing range is mainly determined by the
distance between the Led and phototransistor. Look at QRB1113, QRB1114.
7 cm is still pretty large for an unfocussed sensor, and you'll likely have some
sensitivity to background light levels.
I had another idea. Take 2 of your CNY70 sensors and mount them side by side
with 2-sided tape/etc, and with the phototransistor of one and the Led of the
other to the outside. Use those for input-output.This should sort of emulate a
QRB1113.