Merge pull request #21 from tekktrik/dev/switch-bus-device

Switch to adafruit_bus_device dependency

Author: FoamyGuy

README.rst

@@ -20,6 +20,7 @@ Dependencies
 This driver depends on:
 
 * `Adafruit CircuitPython <https://github.com/adafruit/circuitpython>`_
+* `Bus Device <https://github.com/adafruit/Adafruit_CircuitPython_BusDevice>`_
 
 Please ensure all dependencies are available on the CircuitPython filesystem.
 This is easily achieved by downloading

adafruit_sharpmemorydisplay.py

@@ -30,6 +30,7 @@
 
 from micropython import const
 import adafruit_framebuf
+from adafruit_bus_device.spi_device import SPIDevice
 
 try:
     import numpy
@@ -62,11 +63,10 @@ class SharpMemoryDisplay(adafruit_framebuf.FrameBuffer):
     # pylint: disable=too-many-instance-attributes,abstract-method
 
     def __init__(self, spi, scs_pin, width, height, *, baudrate=2000000):
-        self._scs_pin = scs_pin
         scs_pin.switch_to_output(value=True)
-        self._baudrate = baudrate
-        # The SCS pin is active HIGH so we can't use bus_device. exciting!
-        self._spi = spi
+        self.spi_device = SPIDevice(
+            spi, scs_pin, cs_active_value=True, baudrate=baudrate
+        )
         # prealloc for when we write the display
         self._buf = bytearray(1)
 
@@ -80,34 +80,28 @@ def __init__(self, spi, scs_pin, width, height, *, baudrate=2000000):
 
     def show(self):
         """write out the frame buffer via SPI, we use MSB SPI only so some
-        bit-swapping is rquired. The display also uses inverted CS for some
-        reason so we con't use bus_device"""
-
-        # CS pin is inverted so we have to do this all by hand
-        while not self._spi.try_lock():
-            pass
-        self._spi.configure(baudrate=self._baudrate)
-        self._scs_pin.value = True
-
-        # toggle the VCOM bit
-        self._buf[0] = _SHARPMEM_BIT_WRITECMD
-        if self._vcom:
-            self._buf[0] |= _SHARPMEM_BIT_VCOM
-        self._vcom = not self._vcom
-        self._spi.write(self._buf)
-
-        slice_from = 0
-        line_len = self.width // 8
-        for line in range(self.height):
-            self._buf[0] = reverse_bit(line + 1)
-            self._spi.write(self._buf)
-            self._spi.write(memoryview(self.buffer[slice_from : slice_from + line_len]))
-            slice_from += line_len
-            self._buf[0] = 0
-            self._spi.write(self._buf)
-        self._spi.write(self._buf)  # we send one last 0 byte
-        self._scs_pin.value = False
-        self._spi.unlock()
+        bit-swapping is required.
+        """
+
+        with self.spi_device as spi:
+
+            # toggle the VCOM bit
+            self._buf[0] = _SHARPMEM_BIT_WRITECMD
+            if self._vcom:
+                self._buf[0] |= _SHARPMEM_BIT_VCOM
+            self._vcom = not self._vcom
+            spi.write(self._buf)
+
+            slice_from = 0
+            line_len = self.width // 8
+            for line in range(self.height):
+                self._buf[0] = reverse_bit(line + 1)
+                spi.write(self._buf)
+                spi.write(memoryview(self.buffer[slice_from : slice_from + line_len]))
+                slice_from += line_len
+                self._buf[0] = 0
+                spi.write(self._buf)
+            spi.write(self._buf)  # we send one last 0 byte
 
     def image(self, img):
         """Set buffer to value of Python Imaging Library image.  The image should

requirements.txt

@@ -4,3 +4,4 @@
 
 Adafruit-Blinka
 adafruit-circuitpython-framebuf
+adafruit-circuitpython-busdevice

setup.py

@@ -34,7 +34,11 @@
     # Author details
     author="Adafruit Industries",
     author_email="[email protected]",
-    install_requires=["Adafruit-Blinka", "adafruit-circuitpython-framebuf"],
+    install_requires=[
+        "Adafruit-Blinka",
+        "adafruit-circuitpython-framebuf",
+        "adafruit-circuitpython-busdevice",
+    ],
     # Choose your license
     license="MIT",
     # See https://pypi.python.org/pypi?%3Aaction=list_classifiers