kopia lustrzana https://github.com/pimoroni/pimoroni-pico
68 wiersze
2.0 KiB
Python
68 wiersze
2.0 KiB
Python
import math
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import time
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from pimoroni_i2c import PimoroniI2C
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from pimoroni import BREAKOUT_GARDEN_I2C_PINS # or PICO_EXPLORER_I2C_PINS or HEADER_I2C_PINS
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from breakout_encoder_wheel import BreakoutEncoderWheel, CENTRE, GPIOS, NUM_GPIOS
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from breakout_ioexpander import PWM
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"""
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Output a sine wave PWM sequence on the Encoder Wheel's side GPIO pins.
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Press the centre button or Ctrl+C to stop the program.
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"""
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# Constants
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SPEED = 5 # The speed that the PWM will cycle at
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UPDATES = 50 # How many times to update LEDs and Servos per second
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UPDATE_RATE_US = 1000000 // UPDATES
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FREQUENCY = 1000 # The frequency to run the PWM at
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# Create a new BreakoutEncoderWheel
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i2c = PimoroniI2C(**BREAKOUT_GARDEN_I2C_PINS)
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wheel = BreakoutEncoderWheel(i2c)
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# Set the PWM frequency for the GPIOs
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period = wheel.gpio_pwm_frequency(FREQUENCY)
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# Set the GPIO pins to PWM outputs
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for g in GPIOS:
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wheel.gpio_pin_mode(g, PWM)
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# Variables
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offset = 0.0
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# Sleep until a specific time in the future. Use this instead of time.sleep() to correct for
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# inconsistent timings when dealing with complex operations or external communication
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def sleep_until(end_time):
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time_to_sleep = time.ticks_diff(end_time, time.ticks_us())
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if time_to_sleep > 0:
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time.sleep_us(time_to_sleep)
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# Make PWM waves until the centre button is pressed
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while not wheel.pressed(CENTRE):
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# Record the start time of this loop
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start_time = time.ticks_us()
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offset += SPEED / 1000.0
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# Update all the PWMs
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for i in range(NUM_GPIOS):
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angle = ((i / NUM_GPIOS) + offset) * math.pi
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duty = int(((math.sin(angle) / 2) + 0.5) * period)
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# Set the GPIO pin to the new duty cycle, but do not load it yet
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wheel.gpio_pin_value(GPIOS[i], duty, load=False)
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# Have all the PWMs load at once
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wheel.gpio_pwm_load()
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# Sleep until the next update, accounting for how long the above operations took to perform
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sleep_until(time.ticks_add(start_time, UPDATE_RATE_US))
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# Turn off the PWM outputs
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for g in GPIOS:
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wheel.gpio_pin_value(g, 0)
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