firmware/shared/ssd1306.py
2026-03-16 13:48:28 -04:00

234 lines
8.2 KiB
Python

# (c) Copyright 2018 by Coinkite Inc. This file is covered by license found in COPYING-CC.
#
# ssd1306.py - MicroPython SSD1306 OLED driver, with SPI interface
#
# Copied from ../external/micropython/drivers/display/ssd1306.py
#
import time
from micropython import const
import framebuf
# register definitions
SET_CONTRAST = const(0x81)
SET_ENTIRE_ON = const(0xa4)
SET_NORM_INV = const(0xa6)
SET_DISP = const(0xae)
SET_MEM_ADDR = const(0x20)
SET_COL_ADDR = const(0x21)
SET_PAGE_ADDR = const(0x22)
SET_DISP_START_LINE = const(0x40)
SET_SEG_REMAP = const(0xa0)
SET_MUX_RATIO = const(0xa8)
SET_COM_OUT_DIR = const(0xc0)
SET_DISP_OFFSET = const(0xd3)
SET_COM_PIN_CFG = const(0xda)
SET_DISP_CLK_DIV = const(0xd5)
SET_PRECHARGE = const(0xd9)
SET_VCOM_DESEL = const(0xdb)
SET_CHARGE_PUMP = const(0x8d)
# Subclassing FrameBuffer provides support for graphics primitives
# see <http://docs.micropython.org/en/latest/pyboard/library/framebuf.html>
#
class SSD1306(framebuf.FrameBuffer):
def __init__(self, width, height, is_mk5):
self.width = width
self.height = height
self.is_mk5 = is_mk5
self.pages = self.height // 8
self.buffer = bytearray(1024)
#assert len(self.buffer) == self.pages * self.width
super().__init__(self.buffer, self.width, self.height, framebuf.MONO_VLSB)
self.init_display()
def init_display(self):
if not self.is_mk5:
# Mk4 and earlier
cmds = (
SET_DISP | 0x00, # display off
# address setting
SET_MEM_ADDR, 0x00, # horizontal
# resolution and layout
SET_DISP_START_LINE | 0x00,
SET_SEG_REMAP | 0x01, # column addr 127 mapped to SEG0
SET_MUX_RATIO, self.height - 1,
SET_COM_OUT_DIR | 0x08, # scan from COM[N] to COM0
SET_DISP_OFFSET, 0x00,
SET_COM_PIN_CFG, 0x12,
# timing and driving scheme
SET_DISP_CLK_DIV, 0xF0,
SET_PRECHARGE, 0xf1,
SET_VCOM_DESEL, 0x30, # 0.83*Vcc
# display
SET_CONTRAST, 0xff, # maximum
SET_ENTIRE_ON, # output follows RAM contents
SET_NORM_INV, # not inverted
# charge pump
SET_CHARGE_PUMP, 0x14)
else:
# Mk5 has external +12v power supply, and different setup protocol
cmds = (
SET_DISP | 0x00, # display off
# address setting
SET_MEM_ADDR, 0x00, # horizontal
# resolution and layout
SET_DISP_START_LINE | 0x00,
SET_SEG_REMAP | 0x00, # column addr 0 mapped to SEG127
SET_MUX_RATIO, self.height - 1,
SET_COM_OUT_DIR | 0x00, # scan from COM[8] to COM[N]
SET_DISP_OFFSET, 0x00,
SET_COM_PIN_CFG, 0x12,
# timing and driving scheme
SET_DISP_CLK_DIV, 0xF0,
SET_PRECHARGE, 0x22,
SET_VCOM_DESEL, 0x40, # per spec sheet
# display
SET_CONTRAST, 0x85, # NOT maximum, because spec sheet
SET_ENTIRE_ON, # output follows RAM contents
SET_NORM_INV, # not inverted
SET_CHARGE_PUMP, 0x10, # charge pump: DISABLE
)
self.write_cmds(cmds)
self.fill(0)
self.show()
self.write_cmd(SET_DISP | 0x01)
def write_cmds(self, cmds):
for c in cmds:
self.write_cmd(c)
def poweroff(self):
self.write_cmd(SET_DISP | 0x00)
def poweron(self):
self.write_cmd(SET_DISP | 0x01)
def contrast(self, contrast):
# brightness: normal = 0x7f, brightness=0xff, dim=0x00 (but they are all very similar)
if self.is_mk5:
# - limit to a specific max value from OLED specs used on Mk5
contrast = max(contrast, 0x85)
self.write_cmd(SET_CONTRAST)
self.write_cmd(contrast)
def invert(self, invert):
self.write_cmd(SET_NORM_INV | (invert & 1))
def show(self):
self.write_cmd(SET_COL_ADDR)
self.write_cmd(0)
self.write_cmd(self.width - 1)
self.write_cmd(SET_PAGE_ADDR)
self.write_cmd(0)
self.write_cmd(self.pages - 1)
self.write_data(self.buffer)
def busy_bar(self, enable, pattern):
# Render a continuous activity (not progress) bar in lower 8 lines of display
# - using OLED itself to do the animation, so smooth and CPU free
# - cannot preserve bottom 8 lines, since we have to destructively write there
# - assumes normal horz addr mode: 0x20, 0x00
# - speed_code=>framedelay: 0=5fr, 1=64fr, 2=128, 3=256, 4=3, 5=4, 6=25, 7=2frames
# unused: assert 0 <= speed_code <= 7
setup = bytes([
0x21, 0x00, 0x7f, # setup column address range (start, end): 0-127
0x22, 7, 7, # setup page start/end address: page 7=last 8 lines
])
if not self.is_mk5:
animate = bytes([
0x2e, # stop animations in progress
0x26, # scroll leftwards (stock ticker mode)
0, # placeholder
7, # start 'page' (vertical)
5, # "speed_code" # scroll speed: 7=fastest, but no order to it
7, # end 'page'
0, 0x7f, # start/end columns
0x2f # start
])
else:
# SSD1309? doesn't implement 0x26 but has other commands
animate = bytes([
0x2e, # stop animations in progress
0x29, # Vert+Right horz animation setup
1, # A: enable horz scroll
7, # B: start 'page' (vertical)
5, # C: "speed_code" # scroll speed: 7=fastest, but no order to it
7, # D: end 'page'
1, # E: vert scrolling offset (unused)
0, 0x7f, # F,G: start/end columns
0xa3, # Set Vertical scroll Area
0, 0, # A, B: # of rows in fixed vs. scroll area
0x2f # start animating
])
cleanup = bytes([
0x2e, # stop animation
0x20, 0x00, # horz addr-ing mode
0x21, 0x00, 0x7f, # setup column address range (start, end): 0-127
0x22, 7, 7, # setup page start/end address: page 7=last 8 lines
])
if not enable:
# stop animation, and redraw old (new) screen
self.write_cmds(cleanup)
else:
# needs a pattern that repeats nicely mod 128
self.write_cmds(setup)
self.write_data(pattern)
self.write_cmds(animate)
class SSD1306_SPI(SSD1306):
def __init__(self, width, height, spi, dc, res, cs, is_mk5=False):
self.spi = spi
self.dc = dc
self.cs = cs
self.res = res
# initial states
dc(0)
cs(1)
# reset sequence
res(1)
time.sleep_ms(1)
res(0)
time.sleep_ms(10)
res(1)
super().__init__(width, height, is_mk5)
def _setup_spi(self):
# need to re-do this constantly
# max chip can do, still slower than display limit tho
# - 40Mhz (target) is fine for short-cabled Mk4 (actual is lower?)
# - max spec is 10Mhz on Mk5
rate = 40_000_000 if not self.is_mk5 else 10_000_000
self.spi.init(baudrate=rate, polarity=0, phase=0)
def write_cmd(self, cmd):
self._setup_spi()
self.cs(1)
self.dc(0)
self.cs(0)
self.spi.write(bytearray([cmd]))
self.cs(1)
def write_data(self, buf):
self._setup_spi()
self.cs(1)
self.dc(1)
self.cs(0)
self.spi.write(buf)
self.cs(1)
# EOF