Simple Obstacle Identification Sensor Circuit designed by using IR LED, Photodiode and Operational Amplifier LM358P. This circuit will detect any objects that reflects IR light beam, for Short distance obstacle detection this circuit will help any Microcontrollers or Standalone circuits. (Refer Ultrasonic Distance detector for long distance Obstacle detection). This circuit will Indicate the detection of obstacle by illuminating LED and rising output voltage at output pin. Here you can connect microcontroller or output actuators for further decisions.
This Simple Obstacle detector circuit works with 5V DC power supply, detection range and accuracy can be tuned by using variable resistor RV1.
Components Required (BOM)
Construction & Working
This Simple Circuit can be build on common PCB or use the following PCB Gerber files. Bend the IR LED and Photodiode according to your required position to detect obstacle. Here IC LM358 configured as Non Inverting Amplifier. Inverting pin connected with variable resistor RV1, to give reference input, Photo diode connected in Reverse bias and signal taken from photo diode is connected with non inverting pin of LM358. IR LED is forward biased hence it always illuminate Infra Red light.
If any obstacle nearby this circuit then IR Light reflects and falls on photodiode, then the current flow changes occurs in photodiode, this changes will be amplified by the LM358 and output voltage changes from near zero to 3V. If there is no obstacle in front of this sensor circuit then output will be near zero.
Printed Circuit Board
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