Notes

Plan

Test speaker without Arduino
can be done by using a function generator and 3.3V square wave with variable frequency
Write AVR C code to generate a square wave of varying frequency via Timer1
Timer1 is used so that a pre-scalar and its calculations don't need to be done
Use a table/array that stores frequencies and the indices correspond to the buttons on the sound board
Create buffers to add recording/saving/playing functionality
the buffers are a sequence of notes (which are the indices of the previous table) that is terminated by some other byte
Figure out how the LCD in the starter kit is programmed
we did this in lab 10 on April 10 and are allowed to use that code
Show the current and surrounding notes in the currently selected buffer (or the note of the soundboard button that was just pressed)
Add a menu on the second row to select the memory buffer (maybe 1-5)
it is controlled by left and right buttons

the speaker was tested with a function generator (from the EspoTek Labrador) outputting a square wave of varying frequency
it is painful above a frequency of 12 kHz and just creates clicks below 30 Hz
it is louder at certain frequencies and quieter at others, and this is not a linear relationship
the speaker's datasheet has a graph of this which can be used to adjust the speaker's volume at the problematic frequencies

other speakers sold on DigiKey have more stable frequency response graphs where the volume does not fluctuate very much compared to the speaker included in the kit
those speakers however use sine waves instead of square waves, so our first step should be focused on figuring out how to send sine waves at certain frequencies, perhaps with fast PWM

Asked Sam how to use PWM to handle no use of DAC.
Test the new speaker on Friday without DAC to see if it sounds okay enough.
Lets Try and talk to Rashid or other EE professors.
I think we should also try and get a DAC from the Lab!
We looked into how to use the shift register to handle the fact that we have to many buttons for the pins on the Uno.
We can ask same for a shift register.
We looked into how to use the LCD display and got some Pseudo code from GPT to help.

since we don't know if we can even get the shift registers on time, it's possible to make our own via another Arduino that has all the buttons connected to it and it sends the data over USART to the speaker Arduino
the length of each note can be saved as how many cycles of the square wave note were generated, perhaps with a prescalar if it's a really long and high frequency note