Capacitive Touch Sensor Used In Visually Impaired Aid Equipments

This paper presents a capacitive touch sensor used in a visually impaired aid equipment that can be easily put into practice using a microcontroller and a few peripheral components. The hardware solution is presented as well as the software and mechanical implementations. The sensor's working principle is simple and relays on measuring the delay introduced by an extra capacitance in a RC network discharge curve. Additionally, relevant physical features of the sensor are presented together with experimental measurements characteristic curves. The sensor will be used to activate the audio feedback in a device used to guide visually impaired individuals in the surrounding background using ultrasonic distance measurements.