Article

The Speaking Sonar Stick

Raspberry Pi + ultrasonics + voice synth = Aid 4 The Blind

Labs Project

Based on a Labs project | May 2015 | Find it here

In good experimental fashion, this project is a valuable study into what can be achieved with ‘commodity embedded technology’ like a Raspberry Pi. This ultrasonic distance measuring “robot” will greet you, measure distances to objects continuously and read the values out loud. It can also be programmed to activate alarms when the measured distance crosses a user-programmed limit. Got a pair of U/S distance sensors and an RPi ready? Then go.

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Materials

www.elektormagazine.com/labs

The Speaking Sonar Stick

www.cepstral.com/raspberrypi

https://sourceforge.net/projects/raspberry-gpio-python/

PCB PDF

Project software

Extra info / Update

* Ultrasonic-assisted walking cane for the blind and visually impaired * Buzzer/vibrator warning outputs for object distance <=1 m and >2 m * Ultrasonic transducer with 0.3 cm resolution * Range values continuously read out loud, with s/w adjustable minimum-delta (typ. 2-5 cm) * Raspberry Pi based * LCD readout (optional) * Freely downloadable RPi code

Components

The BOM (Bill of Materials) is the technically exhaustive listing of parts and other hardware items used to produce the working and tested prototype of any Elektor Labs project. The BOM file contains deeper information than the Component List published for the same project in Elektor Magazine. If required the BOM gets updated directly by our lab engineers. As a reader, you can download the list here.
Want to learn more about our BOM list? Read the BOM list article for extra information.

Download the BOM list

Component list

Component List

Resistors
R1 = 1k?
R2 = 1.8k?
R3,R4 = 100?
R7 = 10k?
P1 = 10k? trimpot, horizontal

Semiconductors
IC1 = MCP23008-E/P, Microchip (Newark/Farnell # 1439387)
D1, D2 = 1N4148
T1,T2 = BS170

Miscellaneous
K1 = socket, 4-way, 90 degrees
K2,K3 = 2-way PCB screw terminal block, 0.22’’ pitch
S1 = tactile switch, 6x6 mm
RE1,RE2 = relay, DPDT, 5V, IMO Precision Controls type UA2-5NU, (Newark/Farnell # 1094048)

Miscellaneous
LCD1 = LCD, alphanumeric, 2x16 characters (Elektor Store # 120061-74)
Ultrasonic distance sensor (Elektor Store # 140194-91)
ELPB-NG prototyping board (Elektor Store)