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42 lines
1.8 KiB
Markdown
42 lines
1.8 KiB
Markdown
# Notes
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## Plan
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- [ ] Test speaker without Arduino
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- can be done by using a function generator and 3.3V square wave
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with variable frequency
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- [ ] Write AVR C code to generate a square wave of varying frequency
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via Timer1
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- Timer1 is used so that a pre-scalar and its calculations don't
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need to be done
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- [ ] Use a table/array that stores frequencies and the indices correspond to
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the buttons on the sound board
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- [ ] Create buffers to add recording/saving/playing functionality
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- the buffers are a sequence of notes (which are the indices of the previous
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table) that is terminated by some other byte
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- [ ] Figure out how the LCD in the starter kit is programmed
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- [ ] Show the current and surrounding notes in the currently selected buffer
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(or the note of the soundboard button that was just pressed)
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- [ ] Add a menu on the second row to select the memory buffer (maybe 1-5)
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- it is controlled by left and right buttons
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## 2024-03-28
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## 2024-03-30
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- the speaker was tested with a function generator (from the
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EspoTek Labrador) outputting a square wave of varying frequency
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- it is painful above a frequency of 12 kHz and just creates clicks
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below 30 Hz
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- it is louder at certain frequencies and quieter at others, and this
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is not a linear relationship
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- the speaker's datasheet has a graph of this which can be used to
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adjust the speaker's volume at the problematic frequencies
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## 2024-04-03
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- other speakers sold on DigiKey have more stable frequency response
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graphs where the volume does not fluctuate very much compared to the
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speaker included in the kit
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- those speakers however use sine waves instead of square waves, so our
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first step should be focused on figuring out how to send sine waves at
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certain frequencies, perhaps with fast PWM
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