mirror of
https://codeberg.org/eel4746_piano/avr_piano.git
synced 2024-11-24 02:00:30 -05:00
69 lines
3.0 KiB
Markdown
69 lines
3.0 KiB
Markdown
# Notes
|
|
|
|
## Plan
|
|
- [x] 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
|
|
- [x] 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
|
|
|
|
## 2024-03-28
|
|
|
|
|
|
## 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
|
|
|
|
## 2024-04-03
|
|
- 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
|
|
|
|
## 2024-04-09
|
|
- 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.
|
|
|
|
## 2024-04-12
|
|
- tested new speaker and it works very well with square waves
|
|
- so sine waves via Fast PWM+RC filter no longer needs to be done
|
|
- soldered speaker to a solderboard
|
|
|
|
## 2024-04-13
|
|
- started working on the project's poster
|
|
|
|
## 2024-04-14
|
|
- 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
|