A Project Submitted in Partial Fulfilment of the Requirements for the Degree of Masters of Science in Embedded and Mobile Systems of the Nelson Mandela African Institution of Science and Technology
Speaking weight scale is an important low vision health aid which measures and announces out
the measured weight. It is valuable in numerous applications such as Bathroom scale, Kitchen
scale and more. Different talking scales have been developed for blind community. Many talking
scales have language option for English, German, French or Spanish. However, only limited
work exists for Swahili speaking visually impaired community in East African Community
(EAC) given the fact that no talking scale can announce weight in Swahili, which is the common
language in EAC. Therefore, this project aims to develop a Swahili speaking weighing machine
to assist visually impaired people in Tanzania. The proposed speaking scale is divided into two
major parts. On the front-end of the design, sensors are used to capture weight parameters. The
captured values are mapped onto sequence of voice patterns. The back-end consists of
transferring a sequence of voice patterns to a loudspeaker whereby the voice patterns are stored
on an SD card. Finally, the developed device has been evaluated on several objects (certified
scale calibration weights) with known weights. Each object was reweighed two times. Placed
certified calibration weights on the scale and note the output. Took the measured object off the
scale and let the scale return to zero. Placed the same object on the scale again. Noted the output
again. The results then showed that the scale displayed the same weights on each object. The
expected weight of given objects was then compared with the recorded ones to assess the
performance of the scale. The results then showed that the scale is able to measure objects,
displays digital output of measured weight and announce it in Swahili language within the
accuracy of 1% error range of the actual weight. The proposed device has a great potential as a
low vision health aid for Swahili speaking. The features of this device can be further improved
to increase the autonomy of blind people to use the device and navigate to the device’s location
safely.