Blackberry Trackball (ICSH044A) driver for Adafruit QtPY/Raspberry Pico. See https://developer.run/63 for context

	# Need to install adafruit_debouncer an adafruit_hid

	import digitalio
	import board
	import time
	import usb_hid
	from adafruit_debouncer import Debouncer
	from adafruit_hid.mouse import Mouse
	import time

	def setup(pin):
	inp = digitalio.DigitalInOut(pin)
	inp.direction = digitalio.Direction.INPUT
	inp.pull = digitalio.Pull.UP
	return Debouncer(inp, interval=0.0001)

	step = 4
	smooth = 8
	accel = 2
	max_accel = 5

	def move(last):
	now = time.time()
	multiplier = max_accel+1+max(last-now,-max_accel)
	return multiplieraccelstep, now

	mouse = Mouse(usb_hid.devices)

	# Raspberry Pico
	# up = setup(board.GP3)
	# down = setup(board.GP2)
	# left = setup(board.GP4)
	# right = setup(board.GP5)

	# Adafruit QtPY
	up = setup(board.A0)
	down = setup(board.A1)
	left = setup(board.A2)
	right = setup(board.A3)

	up_upd = time.time()
	down_upd = time.time()
	left_upd = time.time()
	right_upd = time.time()

	x=0
	y=0

	while True:

	up.update()
	if up.fell:
	mv,up_upd=move(up_upd)
	if y>0:
	y=-mv
	else:
	y-=mv
	else:
	down.update()
	if down.fell:
	mv,down_upd=move(down_upd)
	if y<0:
	y=mv
	else:
	y+=mv

	left.update()
	if left.fell:
	mv,left_upd=move(left_upd)
	if x<0:
	x=mv
	else:
	x+=mv
	else:
	right.update()
	if right.fell:
	mv,right_upd=move(right_upd)
	if x>0:
	x=-mv
	else:
	x-=mv

	mvx = 0
	mvy = 0
	if (x>0):
	x=max(0, x-smooth)
	mvx = smooth
	elif (x<0):
	x=min(0, x+smooth)
	mvx = -smooth

	if (y>0):
	y=max(0, y-smooth)
	mvy = smooth
	elif (y<0):
	y=min(0,y+smooth)
	mvy = -smooth

	if not mvx == 0 or not mvy == 0:
	mouse.move(x=mvx, y=mvy)