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Rasp-Hack-Led-Backpack-Sommaire (voir la source)
Version du 11 février 2013 à 20:34
, 11 février 2013 à 20:34aucun résumé de modification
{{traduction}}
{{traduction}}
== Sommaire ==
If you're interested in writing your own code, the easy way is to start with the examples in the code repository (the .py files starting with 'ex_'), but the following information may be helpful as well.
== Adafruit_LEDBackpack ==
All of the low-level IO and I2C access is passed through A'''dafruit_LEDBackpack.py''', which is used by all of the other classes and examples in the library. This file implements a class named '''LEDBackpack''', which has the following functions:
=== setBrightness ===
setBrightness(brightness)
Sets the display brightness with a value between 0 and 15
=== setBlinkRate ===
setBlinkRate(blinkRate)
Sets the optional blink rate for the display, with one of the following values for blinkRate
* 0 = No Blinking
* 1 = Blink at 2Hz
* 2 = Blink at 1Hz
* 3 = Blink at 1/2 Hz
=== setBufferRow ===
setBufferRow(row, value)
Updates a single row of data. The HT16K33 contains an internal memory of 8 rows, with each row having 16 bits of data. Each row generally corresponds to one character on a 7-segment display or one row of pixels on an 8x8 display.
=== getBuffer ===
getBuffer()
Returns a list of 8 16-bit values representing the current state of the internal buffer, which can be used to update the display without affecting the rest of the content.
=== clear ===
clear()
Clears the contents of the entire buffer
== Adafruit_7Segment ==
The 7-Segment library is encapsulated in the file '''Adafruit_7Segment.py''', and implements a class named '''SevenSegment''' (since class names can't start with a digit). It instantiates and instance of '''Adafruit_LEDBackpack''' internally, and you normally won't need to use the lower level class directly. It implements the following functions:
=== writeDigitRaw ===
writeDigitRaw(charNumber, value)
This will raw a raw 16-bit value to the specified charNumber, which corresponds to a single row in the HT16K33, and one character in the 4x7-segment displays. (Note: row 2 is the colon on most 4 character displays). You can use this to display custom characters that aren't supported natively by the current library.
=== writeDigit ===
writeDigit(charNumber, value, dot=False)
Writes a single decimal (0..9) or hexadecimal (0..9 and A..F) character to the display, with charNumber being the character to update, and value being the digit. You can set a third optional argument, dot, to True to set the decimal place after each character.
=== setColon ===
setColon(state)
You can pass either True of False to this function to enable or disable the colon that is usually connected to row 2 of the HT16K33.
== Adafruit_8x8.py ==
The '''Adafruit_8x8.py''' file implements a class names '''EightByEight''' that can be used to drive 8x8 pixel square LED blocks. It contains the following functions:
=== writeRowRaw ===
writeRowRaw(charNumber, value)
This will update an entire row of data with the specified 16-bit value (though normally only the last 8-bits are used on one-color 8x8 displays. This is faster than setting individual pixels.
=== setPixel ===
setPixel(x, y, color)
This function will update a single pixel within the relevant X/Y space of the display. Please keep in mind that lists in Python are zero-based, meaning to sets pixels 1..8 in each direction you actually use the values 0..7, so the following will enable the pixel 3 over and 5 down:
<nowiki>grid = EightByEight(address=0x70)
grid.setPixel(2, 4)</niwiki>
== Exemples ===
If you need a bit of help, simply looking at the provided example python code:
* '''ex_7segment_clock.py''': Displays the current time on a 4*7-segment display, changing the state of the colon every second
* '''ex_8x8_pixels.py''': Constantly updates every pixel on an 8x8 display, one pixel at a time.
You can run these examples with the following code:
<nowiki>sudo python ex_8x8_pixels.py</nowiki>
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