from ssd1306_setup import WIDTH, HEIGHT, setup
from writer import Writer
import myfont  # Font to use
from time import sleep

use_spi=False  # Tested with a 128*64 I2C connected SSD1306 display
ssd = setup(use_spi)  # Instantiate display: must inherit from framebuf
# Demo drawing geometric shapes
rhs = WIDTH -1
ssd.line(rhs - 20, 0, rhs, 20, 1)  # Demo underlying framebuf methods
square_side = 10
ssd.fill_rect(rhs - square_side, 0, square_side, square_side, 1)
# Instantiate a writer for a specific font
wri = Writer(ssd, myfont)  # verbose = False to suppress console output
Writer.set_textpos(ssd, 0, 0)  # In case a previous test has altered this
#wri.printstring('Sunday\n12 Aug 2018\n10.30am')
ssd.show()

i=90
sleep(1)

while True:
    i=i+1
    print("--- New iteration: ---")
    Writer.set_textpos(ssd, 0, 0)
    wri.printstring(f"{str(i):>5}°")
    ssd.show()
    sleep(2)


main.py

diagram.json

# MicroPython SSD1306 OLED driver, I2C and SPI interfaces
#
# library taken from repository at:
# https://github.com/micropython/micropython/blob/master/drivers/display/ssd1306.py
#
from micropython import const
import framebuf
import time

# 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
# http://docs.micropython.org/en/latest/pyboard/library/framebuf.html
class SSD1306(framebuf.FrameBuffer):
    def __init__(self, width, height, external_vcc):
        self.width = width
        self.height = height
        self.external_vcc = external_vcc
        self.pages = self.height // 8
        self.buffer = bytearray(self.pages * self.width)
        super().__init__(self.buffer, self.width, self.height, framebuf.MONO_VLSB)
        self.init_display()

    def init_display(self):
        for cmd in (
            SET_DISP | 0x00,  # 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,
            0x02 if self.width > 2 * self.height else 0x12,
            # Timing and driving scheme
            SET_DISP_CLK_DIV,
            0x80,
            SET_PRECHARGE,
            0x22 if self.external_vcc else 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,
            0x10 if self.external_vcc else 0x14,
            SET_DISP | 0x01,
        ):  # On
            self.write_cmd(cmd)
        self.fill(0)
        self.show()

    def poweroff(self):
        self.write_cmd(SET_DISP | 0x00)

    def poweron(self):
        self.write_cmd(SET_DISP | 0x01)

    def contrast(self, contrast):
        self.write_cmd(SET_CONTRAST)
        self.write_cmd(contrast)

    def invert(self, invert):
        self.write_cmd(SET_NORM_INV | (invert & 1))

    def show(self):
        x0 = 0
        x1 = self.width - 1
        if self.width == 64:
            # Displays with width of 64 pixels are shifted by 32
            x0 += 32
            x1 += 32
        self.write_cmd(SET_COL_ADDR)
        self.write_cmd(x0)
        self.write_cmd(x1)
        self.write_cmd(SET_PAGE_ADDR)
        self.write_cmd(0)
        self.write_cmd(self.pages - 1)
        self.write_data(self.buffer)


class SSD1306_I2C(SSD1306):
    def __init__(self, width, height, i2c, addr=0x3C, external_vcc=False):
        self.i2c = i2c
        self.addr = addr
        self.temp = bytearray(2)
        self.write_list = [b"\x40", None]  # Co=0, D/C#=1
        super().__init__(width, height, external_vcc)

    def write_cmd(self, cmd):
        self.temp[0] = 0x80  # Co=1, D/C#=0
        self.temp[1] = cmd
        self.i2c.writeto(self.addr, self.temp)

    def write_data(self, buf):
        self.write_list[1] = buf
        self.i2c.writevto(self.addr, self.write_list)


ssd1306.py

# ssd1306_setup.py Demo pogram for rendering arbitrary fonts to an SSD1306 OLED display.
# Device initialisation

# The MIT License (MIT)
#
# Copyright (c) 2016 Peter Hinch
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.


# https://learn.adafruit.com/monochrome-oled-breakouts/wiring-128x32-spi-oled-display
# https://www.proto-pic.co.uk/monochrome-128x32-oled-graphic-display.html

# V0.3 12th Aug 2018

import machine
from ssd1306 import SSD1306_I2C

WIDTH = const(128)
HEIGHT = const(64)

def setup(use_spi=False, soft=True):
    if use_spi:
        # Pyb   SSD
        # 3v3   Vin
        # Gnd   Gnd
        # X1    DC
        # X2    CS
        # X3    Rst
        # X6    CLK
        # X8    DATA
        pdc = machine.Pin('X1', machine.Pin.OUT_PP)
        pcs = machine.Pin('X2', machine.Pin.OUT_PP)
        prst = machine.Pin('X3', machine.Pin.OUT_PP)
        if soft:
            spi = machine.SPI(sck=machine.Pin('X6'), mosi=machine.Pin('X8'), miso=machine.Pin('X7'))
        else:
            spi = machine.SPI(1)
        ssd = SSD1306_SPI(WIDTH, HEIGHT, spi, pdc, prst, pcs)
    else:  # I2C
        # Pyb   SSD
        # 3v3   Vin
        # Gnd   Gnd
        # Y9    CLK
        # Y10   DATA
        if soft:
            pscl = machine.Pin(27, machine.Pin.OPEN_DRAIN)
            psda = machine.Pin(26, machine.Pin.OPEN_DRAIN)
            i2c = machine.I2C(1,scl=pscl, sda=psda)
        else:
            i2c = machine.I2C(2)
        ssd = SSD1306_I2C(WIDTH, HEIGHT, i2c)
    return ssd



ssd1306_setup.py

myfont.py

# writer.py Implements the Writer class.
# Handles colour, word wrap and tab stops

# V0.5.1 Dec 2022 Support 4-bit color display drivers.
# V0.5.0 Sep 2021 Color now requires firmware >= 1.17.
# V0.4.3 Aug 2021 Support for fast blit to color displays (PR7682).
# V0.4.0 Jan 2021 Improved handling of word wrap and line clip. Upside-down
# rendering no longer supported: delegate to device driver.
# V0.3.5 Sept 2020 Fast rendering option for color displays

# Released under the MIT License (MIT). See LICENSE.
# Copyright (c) 2019-2021 Peter Hinch

# A Writer supports rendering text to a Display instance in a given font.
# Multiple Writer instances may be created, each rendering a font to the
# same Display object.

# Timings were run on a pyboard D SF6W comparing slow and fast rendering
# and averaging over multiple characters. Proportional fonts were used.
# 20 pixel high font, timings were 5.44ms/467μs, gain 11.7 (freesans20).
# 10 pixel high font, timings were 1.76ms/396μs, gain 4.36 (arial10).


import framebuf
from uctypes import bytearray_at, addressof
from sys import implementation

__version__ = (0, 5, 1)

fast_mode = True  # Does nothing. Kept to avoid breaking code.

class DisplayState():
    def __init__(self):
        self.text_row = 0
        self.text_col = 0

def _get_id(device):
    if not isinstance(device, framebuf.FrameBuffer):
        raise ValueError('Device must be derived from FrameBuffer.')
    return id(device)

# Basic Writer class for monochrome displays
class Writer():

    state = {}  # Holds a display state for each device

    @staticmethod
    def set_textpos(device, row=None, col=None):
        devid = _get_id(device)
        if devid not in Writer.state:
            Writer.state[devid] = DisplayState()
        s = Writer.state[devid]  # Current state
        if row is not None:
            if row < 0 or row >= device.height:
                raise ValueError('row is out of range')
            s.text_row = row
        if col is not None:
            if col < 0 or col >= device.width:
                raise ValueError('col is out of range')
            s.text_col = col
        return s.text_row,  s.text_col

    def __init__(self, device, font, verbose=True):
        self.devid = _get_id(device)
        self.device = device
        if self.devid not in Writer.state:
            Writer.state[self.devid] = DisplayState()
        self.font = font
        if font.height() >= device.height or font.max_width() >= device.width:
            raise ValueError('Font too large for screen')
        # Allow to work with reverse or normal font mapping
        if font.hmap():
            self.map = framebuf.MONO_HMSB if font.reverse() else framebuf.MONO_HLSB
        else:
            raise ValueError('Font must be horizontally mapped.')
        if verbose:
            fstr = 'Orientation: Horizontal. Reversal: {}. Width: {}. Height: {}.'
            print(fstr.format(font.reverse(), device.width, device.height))
            print('Start row = {} col = {}'.format(self._getstate().text_row, self._getstate().text_col))
        self.screenwidth = device.width  # In pixels
        self.screenheight = device.height
        self.bgcolor = 0  # Monochrome background and foreground colors
        self.fgcolor = 1
        self.row_clip = False  # Clip or scroll when screen fullt
        self.col_clip = False  # Clip or new line when row is full
        self.wrap = True  # Word wrap
        self.cpos = 0
        self.tab = 4

        self.glyph = None  # Current char
        self.char_height = 0
        self.char_width = 0
        self.clip_width = 0

    def _getstate(self):
        return Writer.state[self.devid]

    def _newline(self):
        s = self._getstate()
        height = self.font.height()
        s.text_row += height
        s.text_col = 0
        margin = self.screenheight - (s.text_row + height)
        y = self.screenheight + margin
        if margin < 0:
            if not self.row_clip:
                self.device.scroll(0, margin)
                self.device.fill_rect(0, y, self.screenwidth, abs(margin), self.bgcolor)
                s.text_row += margin

    def set_clip(self, row_clip=None, col_clip=None, wrap=None):
        if row_clip is not None:
            self.row_clip = row_clip
        if col_clip is not None:
            self.col_clip = col_clip
        if wrap is not None:
            self.wrap = wrap
        return self.row_clip, self.col_clip, self.wrap

    @property
    def height(self):  # Property for consistency with device
        return self.font.height()

    def printstring(self, string, invert=False):
        # word wrapping. Assumes words separated by single space.
        q = string.split('\n')
        last = len(q) - 1
        for n, s in enumerate(q):
            if s:
                self._printline(s, invert)
            if n != last:
                self._printchar('\n')

    def _printline(self, string, invert):
        rstr = None
        if self.wrap and self.stringlen(string, True):  # Length > self.screenwidth
            pos = 0
            lstr = string[:]
            while self.stringlen(lstr, True):  # Length > self.screenwidth
                pos = lstr.rfind(' ')
                lstr = lstr[:pos].rstrip()
            if pos > 0:
                rstr = string[pos + 1:]
                string = lstr
                
        for char in string:
            self._printchar(char, invert)
        if rstr is not None:
            self._printchar('\n')
            self._printline(rstr, invert)  # Recurse

    def stringlen(self, string, oh=False):
        if not len(string):
            return 0
        sc = self._getstate().text_col  # Start column
        wd = self.screenwidth
        l = 0
        for char in string[:-1]:
            _, _, char_width = self.font.get_ch(char)
            l += char_width
            if oh and l + sc > wd:
                return True  # All done. Save time.
        char = string[-1]
        _, _, char_width = self.font.get_ch(char)
        if oh and l + sc + char_width > wd:
            l += self._truelen(char)  # Last char might have blank cols on RHS
        else:
            l += char_width  # Public method. Return same value as old code.
        return l + sc > wd if oh else l

    # Return the printable width of a glyph less any blank columns on RHS
    def _truelen(self, char):
        glyph, ht, wd = self.font.get_ch(char)
        div, mod = divmod(wd, 8)
        gbytes = div + 1 if mod else div  # No. of bytes per row of glyph
        mc = 0  # Max non-blank column
        data = glyph[(wd - 1) // 8]  # Last byte of row 0
        for row in range(ht):  # Glyph row
            for col in range(wd -1, -1, -1):  # Glyph column
                gbyte, gbit = divmod(col, 8)
                if gbit == 0:  # Next glyph byte
                    data = glyph[row * gbytes + gbyte]
                if col <= mc:
                    break
                if data & (1 << (7 - gbit)):  # Pixel is lit (1)
                    mc = col  # Eventually gives rightmost lit pixel
                    break
            if mc + 1 == wd:
                break  # All done: no trailing space
        # print('Truelen', char, wd, mc + 1)  # TEST 
        return mc + 1

    def _get_char(self, char, recurse):
        if not recurse:  # Handle tabs
            if char == '\n':
                self.cpos = 0
            elif char == '\t':
                nspaces = self.tab - (self.cpos % self.tab)
                if nspaces == 0:
                    nspaces = self.tab
                while nspaces:
                    nspaces -= 1
                    self._printchar(' ', recurse=True)
                self.glyph = None  # All done
                return

        self.glyph = None  # Assume all done
        if char == '\n':
            self._newline()
            return
        glyph, char_height, char_width = self.font.get_ch(char)
        s = self._getstate()
        np = None  # Allow restriction on printable columns
        if s.text_row + char_height > self.screenheight:
            if self.row_clip:
                return
            self._newline()
        oh = s.text_col + char_width - self.screenwidth  # Overhang (+ve)
        if oh > 0:
            if self.col_clip or self.wrap:
                np = char_width - oh  # No. of printable columns
                if np <= 0:
                    return
            else:
                self._newline()
        self.glyph = glyph
        self.char_height = char_height
        self.char_width = char_width
        self.clip_width = char_width if np is None else np
        
    # Method using blitting. Efficient rendering for monochrome displays.
    # Tested on SSD1306. Invert is for black-on-white rendering.
    def _printchar(self, char, invert=False, recurse=False):
        s = self._getstate()
        self._get_char(char, recurse)
        if self.glyph is None:
            return  # All done
        buf = bytearray(self.glyph)
        if invert:
            for i, v in enumerate(buf):
                buf[i] = 0xFF & ~ v
        fbc = framebuf.FrameBuffer(buf, self.clip_width, self.char_height, self.map)
        self.device.blit(fbc, s.text_col, s.text_row)
        s.text_col += self.char_width
        self.cpos += 1

    def tabsize(self, value=None):
        if value is not None:
            self.tab = value
        return self.tab

    def setcolor(self, *_):
        return self.fgcolor, self.bgcolor

# Writer for colour displays.
class CWriter(Writer):

    @staticmethod
    def create_color(ssd, idx, r, g, b):
        c = ssd.rgb(r, g, b)
        if not hasattr(ssd, 'lut'):
            return c
        if not 0 <= idx <= 15:
            raise ValueError('Color nos must be 0..15')
        x = idx << 1
        ssd.lut[x] = c & 0xff
        ssd.lut[x + 1] = c >> 8
        return idx

    def __init__(self, device, font, fgcolor=None, bgcolor=None, verbose=True):
        if not hasattr(device, 'palette'):
            raise OSError('Incompatible device driver.')
        if implementation[1] < (1, 17, 0):
            raise OSError('Firmware must be >= 1.17.')

        super().__init__(device, font, verbose)
        if bgcolor is not None:  # Assume monochrome.
            self.bgcolor = bgcolor
        if fgcolor is not None:
            self.fgcolor = fgcolor
        self.def_bgcolor = self.bgcolor
        self.def_fgcolor = self.fgcolor

    def _printchar(self, char, invert=False, recurse=False):
        s = self._getstate()
        self._get_char(char, recurse)
        if self.glyph is None:
            return  # All done
        buf = bytearray_at(addressof(self.glyph), len(self.glyph))
        fbc = framebuf.FrameBuffer(buf, self.clip_width, self.char_height, self.map)
        palette = self.device.palette
        palette.bg(self.fgcolor if invert else self.bgcolor)
        palette.fg(self.bgcolor if invert else self.fgcolor)
        self.device.blit(fbc, s.text_col, s.text_row, -1, palette)
        s.text_col += self.char_width
        self.cpos += 1

    def setcolor(self, fgcolor=None, bgcolor=None):
        if fgcolor is None and bgcolor is None:
            self.fgcolor = self.def_fgcolor
            self.bgcolor = self.def_bgcolor
        else:
            if fgcolor is not None:
                self.fgcolor = fgcolor
            if bgcolor is not None:
                self.bgcolor = bgcolor
        return self.fgcolor, self.bgcolor

