The oscillator stops and the LED turns off. The light sensitivity of the circuit is set with the potentiometer P1. When there is no light falling on the LDR, the input of U1 is connected to the ground ...

This is a simple 0 to 9 counter circuit constructed using Arduino! Here, a common cathode 7-segment LED display is connected to Arduino ... 7 and 8 should go to Display pins 7, 6, 4, 2, 1, 9 and 10 in ...