# eighties_arp_synthio.py -- playing with arpeggios, testing my Arpy class
# 20 Jun 2023 - @todbot / Tod Kurt
#
#  - arp arp arp
#  - two pots, two buttons, no keys!
#  - no musical knowledge needed, just plug it, start twisting knobs
#  - video demo: https://www.youtube.com/watch?v=noj92Ae0IQI
#
# UI is:
#  knobA - adjusts root note      (QTPy A0)
#  knobB - adjusts BPM            (QTPY A1)
#  buttonA - changes arp pattern  (QTPy SDA)
#  buttonB - changes num iters up for pattern (QTPy SCL)
#
# Circuit:
# - See: "eighties_arp_bb.png" wiring
# - QT Py RP2040 or similar
# - QTPy RX pin is audio out, going through RC filter (1k + 100nF) to TRS jack
#


import time, random
import board, analogio, keypad
import audiopwmio, audiomixer, synthio
import ulab.numpy as np
import neopixel, rainbowio  # circup install neopixel
from arpy import Arpy

num_voices = 3       # how many voices for each note
lpf_basef = 2500     # filter lowest frequency
lpf_resonance = 1.5  # filter q

knobA = analogio.AnalogIn(board.A0)
knobB = analogio.AnalogIn(board.A1)
keys = keypad.Keys( (board.SDA, board.SCL), value_when_pressed=False )
led = neopixel.NeoPixel(board.NEOPIXEL, 1, brightness=0.1)

audio = audiopwmio.PWMAudioOut(board.RX)  # RX pin on QTPY RP2040

mixer = audiomixer.Mixer(channel_count=1, sample_rate=28000, buffer_size=2048)
synth = synthio.Synthesizer(channel_count=1, sample_rate=28000)
audio.play(mixer)
mixer.voice[0].play(synth)
mixer.voice[0].level = 0.8

# our oscillator waveform, a 512 sample downward saw wave going from +/-30k
wave_saw = np.linspace(30000, -30000, num=512, dtype=np.int16)  # max is +/-32k but gives us headroom
amp_env = synthio.Envelope(attack_level=1, sustain_level=1, release_time=0.5)

voices=[]  # holds our currently sounding voices ('Notes' in synthio speak)

# called by arpy to turn on a note
def note_on(n):
    print("  note on ", n )
    led.fill(rainbowio.colorwheel( n % 12 * 20  ))
    fo = synthio.midi_to_hz(n)
    voices.clear()  # delete any old voices
    for i in range(num_voices):
        f = fo * (1 + i*0.007)
        lpf_f = fo * 8  # a kind of key tracking
        lpf = synth.low_pass_filter( lpf_f, lpf_resonance )
        voices.append( synthio.Note( frequency=f, filter=lpf, envelope=amp_env, waveform=wave_saw) )
    synth.press(voices)

# called by arpy to turn off a note
def note_off(n):
    print("  note off", n)
    led.fill(0)
    synth.release(voices)

# simple range mapper, like Arduino map()
def map_range(s, a1, a2, b1, b2): return  b1 + ((s - a1) * (b2 - b1) / (a2 - a1))

arpy = Arpy()
arpy.note_on_handler = note_on
arpy.note_off_handler = note_off
arpy.on()

arpy.root_note = 37
arpy.set_arp('suspended4th')

arpy.set_bpm( bpm=110, steps_per_beat=4 ) # 110 bpm 16th notes
arpy.set_transpose(distance=12, steps=0)

knobfilter = 0.75
knobAval = knobA.value
knobBval = knobB.value

while True:

    key = keys.events.get()
    if key and key.pressed:
        if key.key_number==0:  # left button changes arp played
            arpy.next_arp()
            print(arpy.arp_name())
        if key.key_number==1:  # right button changes arp up iterations
            steps = (arpy.trans_steps + 1) % 3;
            print("steps",steps)
            arpy.set_transpose(steps=steps)

    # filter noisy adc
    knobAval = knobAval * knobfilter + (1-knobfilter) * knobA.value
    knobBval = knobBval * knobfilter + (1-knobfilter) * knobB.value

    # map knobA to root note
    arpy.root_note = int(map_range( knobAval, 0,65535, 24, 72) )
    # map knobB to bpm
    arpy.set_bpm( map_range(knobBval, 0,65535, 40, 180 ) )

    arpy.update()