2. Introduction
The purpose of this lecture was to use the PIC24FJ128
microcontroller to interface with a standard USB keyboard and both
solely read the output, and then also convert that output to ASCII and
send it to the serial monitor via the UART protocol.
3. Results Task 1: This
task asked us to read the input from the keyboard and toggle the lower
byte led's which corresponded to the number on the keyboard being
pressed, and also output the scan code to the upper byte of led's.
Figure 1 shows the code implemented and Figure 2 shows the results.
Figure 1. Code for Displaying Keyboard Input on On-Board LED's
Figure 2. Results from Displaying Keyboard Input on On-Board LED's
Task 2: This task asked
us to read the input from the keyboard and toggle the lower byte led's
which corresponded to the number on the keyboard being pressed, and
also output the scan code to
the upper byte of led's. It then also asked us to implement a UART
transmitter to pass the ASCII code for the key pressed to the serial
monitor. Figure 3 shows the code implemented and Figure 4 shows the
results.
Figure 3. Code for Displaying Keyboard Input on On-Board LED's and ASCII Characters to the Serial Monitor
Figure 4. Results from Displaying Keyboard Input on On-Board LED's and ASCII Characters to the Serial Monitor
4. Discussion This
assignment helped me understand standard USB protocols and how to
decode scan codes from a modern standard keyboard. The major lesson
learned was in interfacing the UART transmitter and the keyboard
output. That actually took a long amount of time and I was very
surprised to see how well it worked. I was happy to get the ooportunity
to work with the UART protocol, especially with a relatively complex
system like we made for this project.
