--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pcd8544.py	Thu Feb 22 01:13:28 2018 +0100
@@ -0,0 +1,60 @@
+import framebuf
+import time
+
+
+class Display:
+    width = 84
+    height = 48
+    _command = bytearray((0x40, 0x80))
+
+    def __init__(self, spi, dc, rst=None, cs=None):
+        self._spi = spi
+        self._cs = cs or (lambda x: x)
+        self._rst = rst or (lambda x: x)
+        self._dc = dc
+        self._fn = bytearray([0x20])
+        buffer = bytearray(504)
+        self.fb = framebuf.FrameBuffer(buffer, 84, 48, framebuf.MVLSB)
+        self._buffer = memoryview(buffer)
+
+        self.reset()
+        self.contrast()
+
+    def _write(self, data, command=True):
+        self._dc(not command)
+        self._cs(0)
+        self._spi.write(data)
+        self._cs(1)
+
+    def reset(self):
+        self._rst(0)
+        time.sleep_us(100)
+        self._rst(1)
+
+    def active(self, val):
+        if val:
+            self._fn[0] &= ~0x04
+        else:
+            self._fn[0] |= 0x04
+        self._write(self._fn)
+
+    def inverse(self, val):
+        self._write(b'\x0d' if val else b'\x0c')
+
+    def contrast(self, val=63, bias=20, temp=6):
+        if not (0 <= val <= 127 and 16 <= bias <= 23 and 4 <= temp <= 7):
+            raise ValueError()
+        for c in (self._fn[0] | 0x01, temp, bias, 0x80 | val, self._fn[0]):
+            self._write(bytes((c,)))
+
+    def update(self):
+        self._cs(0)
+        index = 0
+        for page in range(6):
+            self._command[0] = 0x40 | page
+            self._dc(0)
+            self._spi.write(self._command)
+            self._dc(1)
+            self._spi.write(self._buffer[index:index + 84])
+            index += self.width
+        self._cs(1)