Circuit Components


Currently the system operates 2 channels at 2 frequencies, 50 kHz and 55 kHz. This allows for 2 objects to be detected over the board, and their movements potentially to be tracked. The control box circuit will need to produce these two signals. A number of different oscillator designs are being considered.


The 4 corner voltages are read from the backgammon sensor and consist of a sum of the 50 kHz and 55 kHz signals. These signals must be separated into 2 channels in order to provide meaningful position readings of each of the objects being detected. A number of active band-pass filter designs are being looked at. There must be enough attenuation of the other unwanted channel in each filter so as to minimize position measurement error. Digital filtering could potentially be an option as well, however latency issues come into play, making it an unlikely that this method will be chosen.


The Radio Drum is a three dimensional motion sensing device. It uses capacitive moments sensing to determine the position of an object moving in a three-dimensional space above a surface. The goal of this project is to redesign the Radio Drum control box for UVATT with the purpose of minimizing cost and size.
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