help reg ir

am trying to make an obstacle avoiding robot. my sensing range is small. i tried to build using ir led transmitter and photodiode. but none of the circuits i tried out is working. the following are the few which i tried.

in the above circuit i used lm 324 instead of lm 358…please some one help me…
also can anyone provide me a circuit that works out fine…pls

An IR transmitter sends out IR. The receiver (the photodiode) senses the IR sent by the transmitter.

How are you using this in an obstacle avoiding robot? The IR transmitter or photodiode would need to be attached to the obstacle to avoid.

I am placing ir led transmitter and photodiode near by…so if there is any obstacle encountered there will be an increase in the output…(triangulation)

Based on your description, you are using one of the circuits posted at this link:

Which one are you using? The low range or high range one? You are going to want to use the high range one, if you aren’t already. If you are using this circuit, are you using the same values of components (outside of the op-amp; which based on the spec sheets I found, seem to be identical, just one has 4 op-amps in the package, whereas the other has only 2)? If not, can you post a schematic of what you are using with the values filled in?

Finally, can you post the schematic showing how you connected the system to the Arduino, as well as you code?


Pwoahh, they like to do it in a complicated way don’t they. I would just use an infa red LED with a resistor on a digital output and an IR sensor on an analog input. No extra crap necessary and for most things it would do you fine :slight_smile: