Hey Viewers in this blog we learn to make interesting projects with LM358 OP-AMP. Here I made two circuits Dark sensor and Obstacle sensor using LDR, IR led and Photodiode. Video Tutorial 1).Dark/Night Sensor Dark sensor consist of LDR and lm358 and a 20K trimpot we can easily adjust the sensitivity of the LDR using the variable resistor. Components Required : 1. LM358 2. LDR 3. 100E, 10K 4. 20K Potentiometer 5. LED circuit diagram : 2). Obstacle/IR Sensor This sensor is used in many projects like line follower robot, automatic dispenser, Distance meserment and many more. In this circuit we have used a IR Led and Photodiode, 20K pot we can adjust the sensitivity of Photodiode. Components Required : 1. LM358 2. IR led & Photodiode 3. 100E*2, 10K*1 4. 20K Potentiometer 5. LED circuit diagram :