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# ePaper2in7V2.py nanogui driver for Pico-ePpaper-2.7_V2
# Tested with RPi Pico
# EPD is subclassed from framebuf.FrameBuffer for use with Writer class and nanogui.
# Optimisations to reduce allocations and RAM use.
# Released under the MIT license see LICENSE
# Thanks to @Peter for a great micropython-nano-gui: https://github.com/peterhinch/micropython-nano-gui
# -----------------------------------------------------------------------------
# * | File : ePaper2in7V2.py
# * | Author : Waveshare team
# * | Function : Electronic paper driver
# * | This version: V1.0
# * | Date : 2022-03-15
# -----------------------------------------------------------------------------
import framebuf
import uasyncio as asyncio
from time import sleep_ms, ticks_ms, ticks_us, ticks_diff
class EPD(framebuf.FrameBuffer):
# A monochrome approach should be used for coding this. The rgb method ensures
# nothing breaks if users specify colors.
@staticmethod
def rgb(r, g, b):
return int((r > 127) or (g > 127) or (b > 127))
def __init__(self, spi, cs, dc, rst, busy, landscape=False, asyn=False, full=True):
self._spi = spi
self._cs = cs # Pins
self._dc = dc
self._rst = rst
self._busy = busy
self._lsc = landscape
self._asyn = asyn
self._full = full
self._as_busy = False # Set immediately on start of task. Cleared when busy pin is logically false (physically 1).
self._updated = asyncio.Event()
# Dimensions in pixels. Waveshare code is portrait mode.
# Public bound variables required by nanogui.
self.width = 264 if landscape else 176
self.height = 176 if landscape else 264
self.demo_mode = False # Special mode enables demos to run
self._buffer = bytearray(self.height * self.width // 8)
self._mvb = memoryview(self._buffer)
mode = framebuf.MONO_VLSB if landscape else framebuf.MONO_HLSB
super().__init__(self._buffer, self.width, self.height, mode)
if self._full:
self.init()
else:
self.init_partial()
def _command(self, command, data=None):
self._dc(0)
self._cs(0)
self._spi.write(command)
self._cs(1)
if data is not None:
self._data(data)
def _data(self, data, buf1=bytearray(1)):
self._dc(1)
for b in data:
self._cs(0)
buf1[0] = b
self._spi.write(buf1)
self._cs(1)
def init(self):
# Hardware reset
self._rst(1)
sleep_ms(200)
self._rst(0)
sleep_ms(20) # 5ms in Waveshare code
self._rst(1)
sleep_ms(200)
# Initialisation
cmd = self._command
cmd(b'\x12') #SWRESET
self.wait_until_ready()
cmd(b'\x45', b'\x00\x00\x07\x01') #set Ram-Y address start/end position
cmd(b'\x4F', b'\x00\x00') # set RAM y address count to 0
cmd(b'\x11', b'\x03') # data entry mode
self.wait_until_ready()
print('Init Done.')
def init_partial(self):
# Hardware reset
self._rst(1)
sleep_ms(200)
self._rst(0)
sleep_ms(20) # 5ms in Waveshare code
self._rst(1)
sleep_ms(200)
# Initialisation
cmd = self._command
cmd(b'\x3c', b'\x80')
cmd(b'\x45', b'\x00\x00\x07\x01') #set Ram-Y address start/end position
cmd(b'\x4F', b'\x00\x00') # set RAM y address count to 0
cmd(b'\x11', b'\x03') # data entry mode
self.wait_until_ready()
print('Init Partial Done.')
def wait_until_ready(self):
sleep_ms(50)
t = ticks_ms()
while not self.ready():
sleep_ms(100)
dt = ticks_diff(ticks_ms(), t)
print('wait_until_ready {}ms {:5.1f}mins'.format(dt, dt/60_000))
async def wait(self):
await asyncio.sleep_ms(0) # Ensure tasks run that might make it unready
while not self.ready():
await asyncio.sleep_ms(100)
# Pause until framebuf has been copied to device.
async def updated(self):
await self._updated.wait()
# For polling in asynchronous code. Just checks pin state.
# 1 == busy. Comment in official code is wrong. Code is correct.
def ready(self):
return not(self._as_busy or (self._busy() == 1)) # 1 == busy
async def _as_show(self, buf1=bytearray(1)):
mvb = self._mvb
send = self._spi.write
cmd = self._command
cmd(b'\x24') # DATA_START_TRANSMISSION_2 not in datasheet
self._dc(1)
# Necessary to deassert CS after each byte otherwise display does not
# clear down correctly
t = ticks_ms()
if self._lsc: # Landscape mode
wid = self.width
tbc = self.height // 8 # Vertical bytes per column
iidx = wid * (tbc - 1) # Initial index
idx = iidx # Index into framebuf
vbc = 0 # Current vertical byte count
hpc = 0 # Horizontal pixel count
for i in range(len(mvb)):
self._cs(0)
buf1[0] = ~mvb[idx] # INVERSION HACK ~data
send(buf1)
self._cs(1)
idx -= self.width
vbc += 1
vbc %= tbc
if not vbc:
hpc += 1
idx = iidx + hpc
if not(i & 0x1f) and (ticks_diff(ticks_ms(), t) > 20):
await asyncio.sleep_ms(0)
t = ticks_ms()
else:
for i, b in enumerate(mvb):
self._cs(0)
buf1[0] = ~b # INVERSION HACK ~data
send(buf1)
self._cs(1)
if not(i & 0x1f) and (ticks_diff(ticks_ms(), t) > 20):
await asyncio.sleep_ms(0)
t = ticks_ms()
self._updated.set() # framebuf has now been copied to the device
self._updated.clear()
if self._full:
print('sync full refresh')
cmd(b'\x22', b'\xF7') # DISPLAY_REFRESH
cmd(b'\x20')
else:
print('sync partial refresh')
cmd(b'\x22', b'\xFF') # DISPLAY_REFRESH
cmd(b'\x20')
await asyncio.sleep(1)
while self._busy() == 1:
await asyncio.sleep_ms(200) # Don't release lock until update is complete
self._as_busy = False
# draw the current frame memory. Blocking time ~180ms
def show(self, buf1=bytearray(1)):
if self._asyn:
if self._as_busy:
raise RuntimeError('Cannot refresh: display is busy.')
self._as_busy = True
asyncio.create_task(self._as_show())
return
t = ticks_us()
mvb = self._mvb
send = self._spi.write
cmd = self._command
cmd(b'\x24') # DATA_START_TRANSMISSION_2 not in datasheet
self._dc(1)
# Necessary to deassert CS after each byte otherwise display does not
# clear down correctly
if self._lsc: # Landscape mode
wid = self.width
tbc = self.height // 8 # Vertical bytes per column
iidx = wid * (tbc - 1) # Initial index
idx = iidx # Index into framebuf
vbc = 0 # Current vertical byte count
hpc = 0 # Horizontal pixel count
for _ in range(len(mvb)):
self._cs(0)
buf1[0] = ~mvb[idx] # INVERSION HACK ~data
send(buf1)
self._cs(1)
idx -= self.width
vbc += 1
vbc %= tbc
if not vbc:
hpc += 1
idx = iidx + hpc
else:
for b in mvb:
self._cs(0)
buf1[0] = ~b # INVERSION HACK ~data
send(buf1)
self._cs(1)
if self._full:
print('sync full refresh')
cmd(b'\x22', b'\xF7') # DISPLAY_REFRESH
cmd(b'\x20')
else:
print('sync partial refresh')
cmd(b'\x22', b'\xFF') # DISPLAY_REFRESH
cmd(b'\x20')
te = ticks_us()
print('show time', ticks_diff(te, t)//1000, 'ms')
if not self.demo_mode:
# Immediate return to avoid blocking the whole application.
# User should wait for ready before calling refresh()
return
self.wait_until_ready()
sleep_ms(2000) # Give time for user to see result
# to wake call init()
def sleep(self):
self._as_busy = False
self.wait_until_ready()
cmd = self._command
cmd(b'\x10', b'\01') # DEEP_SLEEP (Waveshare and mcauser)
self._rst(0) # According to schematic this turns off the power