85 lines
2.6 KiB
Python
85 lines
2.6 KiB
Python
"""
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`analog_output.py`
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===============================================================================
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PWM a LED from Adafruit IO!
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Tutorial Link: https://learn.adafruit.com/adafruit-io-basics-analog-output
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Adafruit invests time and resources providing this open source code.
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Please support Adafruit and open source hardware by purchasing
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products from Adafruit!
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Author(s): Brent Rubell for Adafruit Industries
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Copyright (c) 2018 Adafruit Industries
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Licensed under the MIT license.
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All text above must be included in any redistribution.
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Dependencies:
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- Adafruit_Blinka
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(https://github.com/adafruit/Adafruit_Blinka)
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- Adafruit_CircuitPython_PCA9685
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(https://github.com/adafruit/Adafruit_CircuitPython_PCA9685)
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"""
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# import system libraries
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import time
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# import Adafruit Blinka
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from board import SCL, SDA
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from busio import I2C
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# import the PCA9685 module.
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from adafruit_pca9685 import PCA9685
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# import Adafruit IO REST client
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from Adafruit_IO import Client, Feed, RequestError
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# Set to your Adafruit IO key.
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# Remember, your key is a secret,
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# so make sure not to publish it when you publish this code!
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ADAFRUIT_IO_KEY = 'YOUR_IO_KEY'
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# Set to your Adafruit IO username.
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# (go to https://accounts.adafruit.com to find your username)
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ADAFRUIT_IO_USERNAME = 'YOUR_IO_USERNAME'
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# Create the I2C bus interface.
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i2c_bus = I2C(SCL, SDA)
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# Create a simple PCA9685 class instance.
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pca = PCA9685(i2c_bus)
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PCA_CHANNEL = 4
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# Set the PWM frequency to 60hz.
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pca.frequency = 60
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prev_read = 0
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# Create an instance of the REST client.
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aio = Client(ADAFRUIT_IO_USERNAME, ADAFRUIT_IO_KEY)
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try: # if we have a 'analog' feed
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analog = aio.feeds('analog')
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except RequestError: # create an `analog` feed
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feed = Feed(name='analog')
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analog = aio.create_feed(feed)
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def map_range(x, in_min, in_max, out_min, out_max):
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"""re-maps a number from one range to another."""
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mapped = (x-in_min) * (out_max - out_min) / (in_max-in_min) + out_min
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if out_min <= out_max:
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return max(min(mapped, out_max), out_min)
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return min(max(mapped, out_max), out_min)
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while True:
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# grab the `analog` feed value
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analog_read = aio.receive(analog.key)
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if analog_read.value != prev_read:
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print('received <- ', analog_read.value)
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# map the analog value from 0 - 1023 to 0 - 65534
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analog_value = map_range(int(analog_read.value), 0, 1024, 0, 65534)
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# set the LED to the mapped feed value
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pca.channels[PCA_CHANNEL].duty_cycle = int(analog_value)
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prev_read = analog_read.value
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# timeout so we don't flood IO with requests
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time.sleep(0.5)
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