# SPDX-FileCopyrightText: 2016 Philip R. Moyer for Adafruit Industries
# SPDX-FileCopyrightText: 2016 Radomir Dopieralski for Adafruit Industries
# SPDX-FileCopyrightText: 2021 Daniel Flanagan
#
# SPDX-License-Identifier: MIT
"""
`adafruit_max7219.max7219` - MAX7219 LED Matrix/Digit Display Driver
========================================================================
CircuitPython library to support MAX7219 LED Matrix/Digit Display Driver.
This library supports the use of the MAX7219-based display in CircuitPython,
either an 8x8 matrix or a 8 digit 7-segment numeric display.
See Also
=========
* matrices.Maxtrix8x8 is a class support an 8x8 led matrix display
* matrices.CustomMatrix is a class support a custom sized constellation of 8x8 led matrix displays
* bcddigits.BCDDigits is a class that support the 8 digit 7-segment display
Beware that most CircuitPython compatible hardware are 3.3v logic level! Make
sure that the input pin is 5v tolerant.
* Author(s): Michael McWethy
Implementation Notes
--------------------
**Hardware:**
* Adafruit `MAX7219CNG LED Matrix/Digit Display Driver -
MAX7219 <https://www.adafruit.com/product/453>`_ (Product ID: 453)
**Software and Dependencies:**
* Adafruit CircuitPython firmware for the ESP8622 and M0-based boards:
https://github.com/adafruit/circuitpython/releases
* Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
**Notes:**
#. Datasheet: https://cdn-shop.adafruit.com/datasheets/MAX7219.pdf
"""
# MicroPython MAX7219 driver, SPI interfaces
import digitalio
from adafruit_bus_device import spi_device
from micropython import const
import adafruit_framebuf as framebuf
try:
# Used only for typing
import typing # pylint: disable=unused-import
import busio
except ImportError:
pass
__version__ = "0.0.0+auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_MAX7219.git"
# register definitions
_DIGIT0 = const(1)
_INTENSITY = const(10)
[docs]
class MAX7219:
"""
MAX7219 - driver for displays based on max7219 chip_select
:param int width: the number of pixels wide
:param int height: the number of pixels high
:param ~busio.SPI spi: an spi busio or spi bitbangio object
:param ~digitalio.DigitalInOut chip_select: digital in/out to use as chip select signal
:param int baudrate: for SPIDevice baudrate (default 8000000)
:param int polarity: for SPIDevice polarity (default 0)
:param int phase: for SPIDevice phase (default 0)
"""
def __init__(
self,
width: int,
height: int,
spi: busio.SPI,
cs: digitalio.DigitalInOut, # pylint: disable=invalid-name
*,
baudrate: int = 8000000,
polarity: int = 0,
phase: int = 0
):
self._chip_select = cs
self._chip_select.direction = digitalio.Direction.OUTPUT
self._spi_device = spi_device.SPIDevice(
spi, cs, baudrate=baudrate, polarity=polarity, phase=phase
)
self._buffer = bytearray((height // 8) * width)
self.framebuf = framebuf.FrameBuffer1(self._buffer, width, height)
self.width = width
self.height = height
self.init_display()
[docs]
def init_display(self) -> None:
"""Must be implemented by derived class (``matrices``, ``bcddigits``)"""
[docs]
def brightness(self, value: int) -> None:
"""
Controls the brightness of the display.
:param int value: 0->15 dimmest to brightest
"""
if not 0 <= value <= 15:
raise ValueError("Brightness out of range")
self.write_cmd(_INTENSITY, value)
[docs]
def show(self) -> None:
"""
Updates the display.
"""
for ypos in range(8):
self.write_cmd(_DIGIT0 + ypos, self._buffer[ypos])
[docs]
def fill(self, bit_value: int) -> None:
"""
Fill the display buffer.
:param int bit_value: value > 0 set the buffer bit, else clears the buffer bit
"""
self.framebuf.fill(bit_value)
[docs]
def pixel(self, xpos: int, ypos: int, bit_value: int = None) -> None:
"""
Set one buffer bit
:param int xpos: x position to set bit
:param int ypos: y position to set bit
:param int bit_value: value > 0 sets the buffer bit, else clears the buffer bit
"""
bit_value = 0x01 if bit_value else 0x00
self.framebuf.pixel(xpos, ypos, bit_value)
[docs]
def write_cmd(self, cmd: int, data: int) -> None:
"""
Writes a command to spi device.
:param int cmd: register address to write data to
:param int data: data to be written to commanded register
"""
# print('cmd {} data {}'.format(cmd,data))
self._chip_select.value = False
with self._spi_device as my_spi_device:
my_spi_device.write(bytearray([cmd, data]))
[docs]
class ChainableMAX7219(MAX7219):
"""
Daisy Chainable MAX7219 - driver for cascading displays based on max7219 chip_select
:param int width: the number of pixels wide
:param int height: the number of pixels high
:param ~busio.SPI spi: an spi busio or spi bitbangio object
:param ~digitalio.DigitalInOut chip_select: digital in/out to use as chip select signal
:param int baudrate: for SPIDevice baudrate (default 8000000)
:param int polarity: for SPIDevice polarity (default 0)
:param int phase: for SPIDevice phase (default 0)
"""
def __init__(
self,
width: int,
height: int,
spi: busio.SPI,
cs: digitalio.DigitalInOut,
*,
baudrate: int = 8000000,
polarity: int = 0,
phase: int = 0
):
self.chain_length = (height // 8) * (width // 8)
super().__init__(
width, height, spi, cs, baudrate=baudrate, polarity=polarity, phase=phase
)
self._buffer = bytearray(self.chain_length * 8)
self.framebuf = framebuf.FrameBuffer1(self._buffer, self.chain_length * 8, 8)
[docs]
def write_cmd(self, cmd: int, data: int) -> None:
"""
Writes a command to spi device.
:param int cmd: register address to write data to
:param int data: data to be written to commanded register
"""
# print('cmd {} data {}'.format(cmd,data))
self._chip_select.value = False
with self._spi_device as my_spi_device:
for _ in range(self.chain_length):
my_spi_device.write(bytearray([cmd, data]))
[docs]
def show(self) -> None:
"""
Updates the display.
"""
for ypos in range(8):
self._chip_select.value = False
with self._spi_device as my_spi_device:
for chip in range(self.chain_length):
my_spi_device.write(
bytearray(
[
_DIGIT0 + ypos,
self._buffer[ypos * self.chain_length + chip],
]
)
)