120 lines
4.0 KiB
Python
120 lines
4.0 KiB
Python
from __future__ import print_function
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from __future__ import division
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import platform
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import numpy as np
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import config
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# ESP8266 uses WiFi communication
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if config.DEVICE == 'esp8266':
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import socket
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_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
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# Raspberry Pi controls the LED strip directly
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elif config.DEVICE == 'pi':
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import neopixel
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strip = neopixel.Adafruit_NeoPixel(config.N_PIXELS, config.LED_PIN,
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config.LED_FREQ_HZ, config.LED_DMA,
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config.LED_INVERT, config.BRIGHTNESS)
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strip.begin()
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_gamma = np.load(config.GAMMA_TABLE_PATH)
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"""Gamma lookup table used for nonlinear brightness correction"""
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_prev_pixels = np.tile(253, (3, config.N_PIXELS))
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"""Pixel values that were most recently displayed on the LED strip"""
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pixels = np.tile(1, (3, config.N_PIXELS))
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"""Pixel values for the LED strip"""
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def _update_esp8266():
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"""Sends UDP packets to ESP8266 to update LED strip values
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The ESP8266 will receive and decode the packets to determine what values
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to display on the LED strip. The communication protocol supports LED strips
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with a maximum of 256 LEDs.
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The packet encoding scheme is:
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|i|r|g|b|
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where
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i (0 to 255): Index of LED to change (zero-based)
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r (0 to 255): Red value of LED
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g (0 to 255): Green value of LED
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b (0 to 255): Blue value of LED
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"""
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global pixels, _prev_pixels
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# Truncate values and cast to integer
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pixels = np.clip(pixels, 0, 255).astype(int)
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# Optionally apply gamma correctio
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p = _gamma[pixels] if config.SOFTWARE_GAMMA_CORRECTION else np.copy(pixels)
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# Send UDP packets when using ESP8266
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is_python_2 = int(platform.python_version_tuple()[0]) == 2
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m = '' if is_python_2 else []
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for i in range(config.N_PIXELS):
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# Ignore pixels if they haven't changed (saves bandwidth)
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if np.array_equal(p[:, i], _prev_pixels[:, i]):
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continue
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if is_python_2:
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m += chr(i) + chr(p[0][i]) + chr(p[1][i]) + chr(p[2][i])
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else:
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m.append(i) # Index of pixel to change
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m.append(p[0][i]) # Pixel red value
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m.append(p[1][i]) # Pixel green value
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m.append(p[2][i]) # Pixel blue value
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m = m if is_python_2 else bytes(m)
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_sock.sendto(m, (config.UDP_IP, config.UDP_PORT))
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_prev_pixels = np.copy(p)
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def _update_pi():
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"""Writes new LED values to the Raspberry Pi's LED strip
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Raspberry Pi uses the rpi_ws281x to control the LED strip directly.
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This function updates the LED strip with new values.
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"""
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global pixels, _prev_pixels
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# Truncate values and cast to integer
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pixels = np.clip(pixels, 0, 255).astype(long)
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# Optional gamma correction
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p = _gamma[pixels] if config.SOFTWARE_GAMMA_CORRECTION else np.copy(pixels)
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# Encode 24-bit LED values in 32 bit integers
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r = np.left_shift(p[0][:].astype(int), 8)
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g = np.left_shift(p[1][:].astype(int), 16)
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b = p[2][:].astype(int)
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rgb = np.bitwise_or(np.bitwise_or(r, g), b)
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# Update the pixels
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for i in range(config.N_PIXELS):
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# Ignore pixels if they haven't changed (saves bandwidth)
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if np.array_equal(p[:, i], _prev_pixels[:, i]):
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continue
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strip._led_data[i] = rgb[i]
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_prev_pixels = np.copy(p)
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strip.show()
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def update():
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"""Updates the LED strip values"""
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if config.DEVICE == 'esp8266':
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_update_esp8266()
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elif config.DEVICE == 'pi':
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_update_pi()
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else:
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raise ValueError('Invalid device selected')
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# Execute this file to run a LED strand test
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# If everything is working, you should see a red, green, and blue pixel scroll
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# across the LED strip continously
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if __name__ == '__main__':
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import time
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# Turn all pixels off
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pixels *= 0
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pixels[0, 0] = 255 # Set 1st pixel red
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pixels[1, 1] = 255 # Set 2nd pixel green
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pixels[2, 2] = 255 # Set 3rd pixel blue
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print('Starting LED strand test')
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while True:
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pixels = np.roll(pixels, 1, axis=1)
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update()
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time.sleep(1)
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