This project has been prepared by Kon-Hyong Kim (kk336), Tae Yong “Tim” Chung (tc228), and Kevin Jin-Ho Ham (kh272) for ECE 476 in Spring 2007.
The hardware
In order to make this project work, we had to work in several different aspects in hardware. In detail, we had to worry about the voice recognition chip (hereafter HM2007) as well as the TV circuit. Finally, we will discuss the consideration of power within the HM2007 programming circuit.
The HM2007
The HM2007, shown on the right, Figure 4, other than what was discussed in the previous section, required a simple low-pass circuit for the microphone. This required the basic capacitor and resistor, thus reducing the noise that went into the chip for recording. Otherwise, except for the extensive wiring required from digital circuitry, not much consideration was required.
Figure 5: The HM2007 Programming Circuit
One interesting aspect that we had to consider while dealing with the HM2007 programming circuit was the issue of enough current for all the chips. Since we were dealing with multiple digital chips, we had to insure that all the chips could show an active high or low. At first, using the power given from the Atmel chips, we had issues driving the seven-segment LED to have it turn on. However, using an outside source coupled with a power regulator solved the problem.
The TV Circuit
This circuit is very much the one implemented from a previous lab. Like in the previous lab, the circuit will attach a filter and a voltage divider to make the television work.
Figure 6: TV Input Circuit
Much of this hardware design is identical from that done from this previous lab. Since we did not have to worry about the analysis for voice recognition, no other filtering was necessary.