42d7e283d2
This error may occur when busnum is incorrect: "IOError: [Errno 16] Device or resource busy" Refer to this Adafruit Forum issue for more information "LED Backpack not working on beaglebone black with debian" https://forums.adafruit.com/viewtopic.php?f=49&t=140344 Signed-off-by: Drew Fustini <drew@pdp7.com>
59 lines
2.5 KiB
Python
59 lines
2.5 KiB
Python
# Copyright (c) 2014 Adafruit Industries
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# Author: Tony DiCola
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#
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# Permission is hereby granted, free of charge, to any person obtaining a copy
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# of this software and associated documentation files (the "Software"), to deal
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# in the Software without restriction, including without limitation the rights
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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# copies of the Software, and to permit persons to whom the Software is
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# furnished to do so, subject to the following conditions:
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#
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# The above copyright notice and this permission notice shall be included in
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# all copies or substantial portions of the Software.
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#
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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# THE SOFTWARE.
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import time
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from Adafruit_LED_Backpack import AlphaNum4
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# Create display instance on default I2C address (0x70) and bus number.
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display = AlphaNum4.AlphaNum4()
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# Alternatively, create a display with a specific I2C address and/or bus.
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# display = AlphaNum4.AlphaNum4(address=0x74, busnum=1)
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# On BeagleBone, try busnum=2 if IOError occurs with busnum=1
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# display = AlphaNum4.AlphaNum4(address=0x74, busnum=2)
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# Initialize the display. Must be called once before using the display.
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display.begin()
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# Scroll a message across the display
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message = 'This is an example of the 4 character alpha-numeric display. THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG? the quick brown fox jumps over the lazy dog!'
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pos = 0
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print('Press Ctrl-C to quit.')
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while True:
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# Clear the display buffer.
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display.clear()
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# Print a 4 character string to the display buffer.
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display.print_str(message[pos:pos+4])
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# Write the display buffer to the hardware. This must be called to
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# update the actual display LEDs.
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display.write_display()
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# Increment position. Wrap back to 0 when the end is reached.
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pos += 1
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if pos > len(message)-4:
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pos = 0
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# Delay for half a second.
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time.sleep(0.5)
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# Note that the alphanumeric display has the same number printing functions
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# as the 7 segment display. See the sevensegment_test.py example for good
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# examples of these functions.
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