Add display.py

This commit is contained in:
Artur Kerge 2023-09-20 17:48:39 +00:00
parent 2a1f61ed4f
commit 119e08bc5a

121
display.py Normal file
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import enum
class Font(enum.Enum):
F61 = (0x61, 5)
F62 = (0x62, 5)
F63 = (0x63, 5)
F64 = (0x64, 5)
F65 = (0x65, 5)
F66 = (0x66, 5)
F67 = (0x67, 5)
F68 = (0x68, 5)
F69 = (0x69, 5)
F70 = (0x70, 5)
F71 = (0x71, 5)
F72 = (0x72, 5)
F73 = (0x73, 5)
F74 = (0x74, 5)
F75 = (0x75, 5)
F76 = (0x76, 5)
SMALL_F = (0x64, 5)
BITMAP = (0x77, 5)
# F<HEIGHT>_<Fat>/<Thin>
F13_F = (0x61, 13) # on 0x70 too
F9_F = (0x62, 9)
F19_F = (0x63, 19)
F7_F = (0x64, 7)
F7 = (0x65, 7)
F6 = (0x66, 7)
SYMBOL = (0x67, 16)
F16_T = (0x68, 16)
F13_T = (0x69, 13)
#F13_F = (0x70, 13)
F15_T = (0x71, 15)
F5 =(0x72, 5)
F13_TT = (0x73, 13)
# 74: Only one character... and only A seems to work
F13 = (0x75, 13) # same as F13_T but wider...
def __init__(self, cmd, height):
self.cmd = cmd
self.height = height
class DisplayBuffer:
""" Acts as a buffer for creating commands to send to the display """
def __init__(self, address: int, width: int, height:int):
self.address = address
self.width = width
self.height = height
# create initial frame buffer
self.reset_buffer()
def reset_buffer(self):
self.buffer = bytearray()
# add display header: 0xff (start), address, 0xA2 (always 0xA2)
self.buffer.extend([0xff, self.address, 0xA2])
# set display size
self.buffer.extend([0xd0, self.width]) # width
self.buffer.extend([0xd1, self.height]) # height
def put_text(self, text:str, x: int = 0, y: int = 0, font: Font = Font.SMALL_F):
# set position (TODO: make the position aware of the font size, y-coordinate seems a bit fishy xD )
self.buffer.extend([0xd2, x]) # x coordinate
self.buffer.extend([0xd3, y]) # y coordinate
# select font
self.buffer.extend([0xd4, font.cmd])
# write characters
# self.buffer.extend([ord(c) for c in text])
self.buffer.extend([c for c in text])
def put_bitmap(self, bitmap: bytearray, x: int = 0, y: int = 0):
# set position
self.buffer.extend([0xd2, x]) # x coordinate
self.buffer.extend([0xd3, y]) # y coordinate
# select bitmap font
self.buffer.extend([0xd4, Font.BITMAP.cmd])
# TODO: write real bitmap data here (somehow xD)
self.buffer.extend(bitmap)
def finalize_buffer(self) -> bytearray:
""" completes the this frame and returns the bytes to be written to the display """
# add checksum
self._add_checksum(self.buffer)
# add stop command
self.buffer.append(0xff)
# reset the buffer and return the old one
buffer = self.buffer
self.reset_buffer()
return buffer
@staticmethod
def _add_checksum(data: bytearray):
""" appends a checksum to the specified data """
# sum all bytes except the first and take the lower 8 bits
csum = sum(data[1:]) & 0xff
# append checksum to data
if csum == 0xfe:
data.extend([0xfe, 0x00])
elif csum == 0xff:
data.extend([0xfe, 0x01])
else:
data.append(csum)