by David Tow and Emily Cheng
After much debugging and tweaking, we finally got our project to work as we specified. All the hardware testing and debugging took a great amount of time. Our wireless drawing device is able to transmit and receive data and draw anywhere on the TV. We did not get to implement it so that it will work like a mouse.
One thing that is worth mentioning here is that we had to make sure that the antennae for both the transmitter and receiver were fully extended in order get best transmission and reception results. In fact, in testing our range, we could draw on the television from anywhere in the laboratory, which is about 15 meters. We were also able to walk out of the laboratory, all the way to the water fountain outside all the labs' area, and still draw on the television; that is about 20 meters. As long as there is not much RF interference, our range and reception are pretty good.
We could draw rather quickly - no measurable delay between movement direction and resulting television image. Our drawing mechanism was also rather accurate. When trying to draw, what we wanted to draw appeared as the image on the television.
Below is a picture of our entire setup working - transmission, reception, and images being drawn on the television. On the oscilloscope, one can see that the receiver is receiving what the transmitter transmitted. On the oscilloscope, the top line with the square waves is the transmitted signal. The bottom line is the received signal. One can see that they are identical with a slight delay of about 60us between transmission and reception.