EE 451 - LAB 7
Part 2: Frequency Detector
Implement the detector discussed in Part 1 of Lab 6.
- Choose a pin on Port B which you will use to indicate whether the
frequency is present or not. Look at the schematic for the 56002 board
(available in the lab) to determine how to connect to this pin. Using the EVM
program, set up this pin as an output. Verify with a logic probe that you can
change the state of this pin.
- Write 56002 code to implement the detector. Put the output from your
bandpass filter to one channel of your D/A, and the output from the detector
to the other. Use your function generator to produce a sine wave of the
correct frequency. Verify that the detector works properly.
- Use a logic probe to verify that the selected output pin goes high when
the selected frequency is present, and goes low when it is absent. For a 1 V
P-P input signal, what are the lowest and highest frequencies which make the
output pin go high? Compare this to your gain plot from last week's lab.