Wearable Sonar Navigation Device for Visually Impaired People

This sonar device informs the user of the presence of obstacles along their way, preventing involuntary collisions. It is designed to be worn as a necklace at the height of the chest, and it uses two ultrasound sensors to control the area in front of the chest and in front of the user's face.
Once an object becomes too close, the device allerts the user with a vibration or a beep sound. The closer the object is to the user, the higher the frequency of this sound or vibration is. The current code sets the feedback to start at a distance of 60cm from the chest, and at a distance of 20cm for the face.




Below, we provide the full specifications to replicate our sonar device at home, namely, the list of the electrical components, the schematic of the PCB, the 3D model of the case, and the mounting instructions.



Schematic:
       - Fritzing model [FZZ]
       - Printing service website [link]


Components:
       - R1 -> 47 ohm
       - R2 -> 220 ohm
       - R3 -> 8.2K ohm
       - T1 -> 2N3904 NPN EBC TO-92
       - D1 -> 1N4001 50V/1A
       - Ultrasound -> HY-SRF05 (2x)
       - Arduino     -> Arduino Nano
       - S1 & S2      -> NKK SwitchesSlide switches SS12SDH2 [link]
       - Batt.         -> Battery pin holder for 1/2 AA cells L 1/2AA 34.5x16x15mm [link]
       - Speaker     -> Speaker 8ohm [link]
       - Engine      -> Vibration Motor 3v 75mA 6mm x 11mm



Case Model:
       - 3D model [OBJ]
       - Makerbot model [thing]
         (printed using Makerbot Replicator 2 [link] )





Software Arduino:
       - Source code [INO]




Mounting: