Obstacle Detection Stick for the Visually Impaired Using HC-SR04 Ultrasonic Sensor and Arduino Nano Microcontroller-based Raindrop Sensor

Aims: With the stick, blind people can not only project their goals well, but also anticipate obstacles from the front, right, left, and unexpected puddles below without physical contact.

Study Design: Obstacle Detection Stick for the Visually Impaired Using HC-SR04 Ultrasonic Sensor and Arduino Nano Microcontroller-Based Raindrop Sensor.

Methodology: Calibration is performed by comparing the output value of the HC-SR04 ultrasonic sensor and the manual meter. The calibrated parameters are the distance of the obstacle at the front, left and right positions. The relationship between the measured values of the design tool and the manual measuring instrument is determined by the linear regression method to obtain the correction equation and the accuracy of the design tool.

Results: Based on the research, the working system of the tool for the blind using an ultrasonic sensor is that when the obstacle is in the left position, the tool will emit a right turn sound and vice versa, when the obstacle is in the front and left position of the sensor, the tool will emit a right turn sound and when the obstacle is in the front and left position of the sensor, the tool will emit a left turn sound, If the obstacle is in the front, left and right positions, the tool will emit a U-turn sound and if the obstacle is in the front position, the tool will emit a U-turn sound, the sound produced comes from the audio card's SD module where the sound was previously recorded and the media used as the obstacle is the card. The percentage level of accuracy obtained by the HC-SR04 ultrasonic sensor in the front position is 96.875%, in the left position is 90.625%, and in the right position is 93.75%. The maximum distance the ultrasonic sensor can detect is 147 cm. In the raindrop sensor, the buzzer sounds when the raindrop sensor detects water if the raindrop sensor reading is more than 5 cm from the bottom of the blind cane, and the buzzer does not sound if the raindrop sensor reading is less than 5 cm.

Conclusion: The HC-SR04 ultrasonic sensor works by using the obstacle's ability to reflect back the ultrasonic waves sent by the ultrasonic sensor to detect the distance between the stick and the obstacle.