# asnano_sync.py Test/demo program for use of nanogui with asyncio # Requires Pyboard for switch and LEDs. # Tested with Adafruit ssd1351 OLED display. # Copyright (c) 2020 Peter Hinch # Released under the MIT License (MIT) - see LICENSE file # Initialise hardware and framebuf before importing modules from color_setup import ssd # Create a display instance import asyncio import pyb import uos from gui.core.writer import CWriter from gui.core.nanogui import refresh from gui.widgets.led import LED from gui.widgets.meter import Meter refresh(ssd, True) # Fonts import gui.fonts.arial10 as arial10 import gui.fonts.freesans20 as freesans20 from gui.core.colors import * color = lambda v: RED if v > 0.7 else YELLOW if v > 0.5 else GREEN txt = lambda v: "ovr" if v > 0.7 else "high" if v > 0.5 else "ok" class MyMeter(Meter): def __init__(self, x, text): CWriter.set_textpos(ssd, 0, 0) # In case previous tests have altered it wri = CWriter(ssd, arial10, GREEN, BLACK, verbose=False) wri.set_clip(True, True, False) super().__init__( wri, 5, x, divisions=4, ptcolor=YELLOW, label=text, style=Meter.BAR, legends=("0.0", "0.5", "1.0"), ) self.led = LED(wri, ssd.height - 16 - wri.height, x, bdcolor=YELLOW, label="over") self.task = asyncio.create_task(self._run()) async def _run(self): while True: v = int.from_bytes(uos.urandom(3), "little") / 16777216 self.value(v, color(v)) self.led.color(color(v)) self.led.text(txt(v), fgcolor=color(v)) # Slow asynchronous data acquisition might occur here. Note # that meters update themselves asynchronously (in a real # application as data becomes available). await asyncio.sleep(v) # Demo variable times async def flash(n, t): led = pyb.LED(n) try: while True: led.toggle() await asyncio.sleep_ms(t) except asyncio.CancelledError: led.off() # Demo tidying up on cancellation. class Killer: def __init__(self): self.sw = pyb.Switch() async def wait(self, t): while t >= 0: if self.sw(): return True await asyncio.sleep_ms(50) t -= 50 return False # The main task instantiates other tasks then does the display update process. async def main(): print("Press Pyboard usr button to stop test.") # Asynchronously flash Pyboard LED's. Because we can. leds = [asyncio.create_task(flash(1, 200)), asyncio.create_task(flash(2, 233))] # Task for each meter and GUI LED mtasks = [MyMeter(2, "left").task, MyMeter(50, "right").task, MyMeter(98, "bass").task] k = Killer() while True: if await k.wait(800): # Switch was pressed break refresh(ssd) for task in mtasks + leds: task.cancel() await asyncio.sleep_ms(0) ssd.fill(0) # Clear display at end. refresh(ssd) def test(): try: asyncio.run(main()) finally: # Reset asyncio case of KeyboardInterrupt asyncio.new_event_loop() print("asnano_sync.test() to re-run test.") test()