Dual axis solar tracker with singlr LDR
LDR would be placed in a pipe which is painted black on the inner sides to reflect light from the sun and direct it to LDR.


No, it would be painted black to avoid reflecting light to the LDR. You want the LDR just to see the direct sunlight.


  i (sic) wanted to ask is it even possible to make solar tracker with single LDR?


Yes, it is possible, but maybe not sensible.







simulate this circuit &ndash; Schematic created using CircuitLab

Figure 1. A dual sensor system turns the tracker to the side with the stronger light. A single sensor would have to oscillate back and forth to determine maximum intensity.

You could take advantage of the fact that the earth only rotates in one direction. The system would have to reset - perhaps against a hard-stop - each night to be in roughly the right position for dawn and then track the sun during the day. It would then have to watch for any decrease in light intensity, start tracking, check that the light level increases and then watch for when it starts to decrease again. I imagine that this could best be done digitally but it doesn't seem like a good strategy.

An alternative means would be to oscillate - maybe every minute - a couple of degrees each way and look for a maximum light level and move to that position.

There would be several problems with this. Any change in light levels due to shadows, clouds, etc., during seeking will affect operation.