serial byte read on keybow2040

code.py

import math
import board
from keybow2040 import Keybow2040, number_to_xy, hsv_to_rgb
import usb_cdc

# Some constants
FULLBRIGHT = 1
MINBRIGHT = 0.05

# Set up Keybow
i2c = board.I2C()
keybow = Keybow2040(i2c)
keys = keybow.keys
console = usb_cdc.serials[0]

# Dicts to stow statuses.
is_pressed = {}
hues = {}

# Per-key init
for key in keys:

    # init to not-pressed
    is_pressed[key.number] = False
    
    # A pressed handler
    @keybow.on_press(key)
    def press_handler(key):
        # note current pressed status
        is_pressed[key.number] = True
        if key.number in hues:
            hue = hues[key.number]
            # Get brightened value.
            r, g, b = hsv_to_rgb(hue, 1, FULLBRIGHT)
            # Display it on the key!
            key.set_led(r, g, b)

    # A release handler
    @keybow.on_release(key)
    def release_handler(key):
        is_pressed[key.number] = False
        if key.number in hues:
            hue = hues[key.number]
            # Get darkened value.
            r, g, b = hsv_to_rgb(hue, 1, MINBRIGHT)
            # Display it on the key!
            key.set_led(r, g, b)

# Increment step to shift animation across keys.
step = 0

while True:
    # Always remember to call keybow.update() on every iteration of your loop!
    keybow.update()

    step += 1
    
    # all keys dim, unless we got some serial bytes this cycle
    value = MINBRIGHT
    if console.in_waiting > 0:
        value=FULLBRIGHT
        # throw away as many bytes as we have in the buffer
        console.read(console.in_waiting)

    for key in keys:
        # Convert the key number to an x/y coordinate to calculate the hue
        # in a matrix style-y.
        x, y = number_to_xy(key.number)

        # Calculate the hue.
        hue = (x + y + (step / 20)) / 8
        hue = hue - int(hue)
        hue = hue - math.floor(hue)
        
        # Stow it for event handlers
        hues[key.number] = hue
        
        # Pick a value (brightness)
        net_value = value
        if is_pressed[key.number]:
        	net_value = FULLBRIGHT
          
        # Convert the hue and value to RGB values.
        r, g, b = hsv_to_rgb(hue, 1, net_value)
        
        # Display it on the key!
        key.set_led(r, g, b)