# 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
- [ ] 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

## 2024-03-28
![](2024-03-28_notes.jpg)

## 2024-03-30
- 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