# 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.
import pyb
import font
# Constants
DISPLAYOFF = 0xAE
SETCONTRAST = 0x81
DISPLAYALLON_RESUME = 0xA4
DISPLAYALLON = 0xA5
NORMALDISPLAY = 0xA6
INVERTDISPLAY = 0xA7
DISPLAYON = 0xAF
SETDISPLAYOFFSET = 0xD3
SETCOMPINS = 0xDA
SETVCOMDETECT = 0xDB
SETDISPLAYCLOCKDIV = 0xD5
SETPRECHARGE = 0xD9
SETMULTIPLEX = 0xA8
SETLOWCOLUMN = 0x00
SETHIGHCOLUMN = 0x10
SETSTARTLINE = 0x40
MEMORYMODE = 0x20
COLUMNADDR = 0x21
PAGEADDR = 0x22
COMSCANINC = 0xC0
COMSCANDEC = 0xC8
SEGREMAP = 0xA0
CHARGEPUMP = 0x8D
EXTERNALVCC = 0x10
SWITCHCAPVCC = 0x20
SETPAGEADDR = 0xB0
SETCOLADDR_LOW = 0x00
SETCOLADDR_HIGH = 0x10
ACTIVATE_SCROLL = 0x2F
DEACTIVATE_SCROLL = 0x2E
SET_VERTICAL_SCROLL_AREA = 0xA3
RIGHT_HORIZONTAL_SCROLL = 0x26
LEFT_HORIZONTAL_SCROLL = 0x27
VERTICAL_AND_RIGHT_HORIZONTAL_SCROLL = 0x29
VERTICAL_AND_LEFT_HORIZONTAL_SCROLL = 0x2A
# I2C devices are accessed through a Device ID. This is a 7-bit
# value but is sometimes expressed left-shifted by 1 as an 8-bit value.
# A pin on SSD1306 allows it to respond to ID 0x3C or 0x3D. The board
# I bought from ebay used a 0-ohm resistor to select between "0x78"
# (0x3c << 1) or "0x7a" (0x3d << 1). The default was set to "0x78"
DEVID = 0x3c
# I2C communication here is either <DEVID> <CTL_CMD> <command byte>
# or <DEVID> <CTL_DAT> <display buffer bytes> <> <> <> <>...
# These two values encode the Co (Continuation) bit as b7 and the
# D/C# (Data/Command Selection) bit as b6.
CTL_CMD = 0x80
CTL_DAT = 0x40
class SSD1306(object):
def __init__(self, pinout, height=32, external_vcc=True, i2c_devid=DEVID):
self.external_vcc = external_vcc
self.height = 32 if height == 32 else 64
self.pages = int(self.height / 8)
self.columns = 128
# Infer interface type from entries in pinout{}
if 'dc' in pinout:
# SPI
rate = 16 * 1024 * 1024
self.spi = pyb.SPI(1, pyb.SPI.MASTER, baudrate=rate, polarity=1, phase=0) # SCK: Y6: MOSI: Y8
self.dc = pyb.Pin(pinout['dc'], pyb.Pin.OUT_PP, pyb.Pin.PULL_DOWN)
self.res = pyb.Pin(pinout['res'], pyb.Pin.OUT_PP, pyb.Pin.PULL_DOWN)
self.offset = 0
else:
# Infer bus number from pin
if pinout['sda'] == 'X10':
self.i2c = pyb.I2C(1)
else:
self.i2c = pyb.I2C(2)
self.i2c.init(pyb.I2C.MASTER, baudrate=400000) # 400kHz
self.devid = i2c_devid
# used to reserve an extra byte in the image buffer AND as a way to
# infer the interface type
self.offset = 1
# I2C command buffer
self.cbuffer = bytearray(2)
self.cbuffer[0] = CTL_CMD
def clear(self):
self.buffer = bytearray(self.offset + self.pages * self.columns)
if self.offset == 1:
self.buffer[0] = CTL_DAT
def write_command(self, command_byte):
if self.offset == 1:
self.cbuffer[1] = command_byte
self.i2c.send(self.cbuffer, addr=self.devid, timeout=5000)
else:
self.dc.low()
self.spi.send(command_byte)
def invert_display(self, invert):
self.write_command(INVERTDISPLAY if invert else NORMALDISPLAY)
def display(self):
self.write_command(COLUMNADDR)
self.write_command(0)
self.write_command(self.columns - 1)
self.write_command(PAGEADDR)
self.write_command(0)
self.write_command(self.pages - 1)
if self.offset == 1:
self.i2c.send(self.buffer, addr=self.devid, timeout=5000)
else:
self.dc.high()
self.spi.send(self.buffer)
def set_pixel(self, x, y, state):
index = x + (int(y / 8) * self.columns)
if state:
self.buffer[self.offset + index] |= (1 << (y & 7))
else:
self.buffer[self.offset + index] &= ~(1 << (y & 7))
def init_display(self):
chargepump = 0x10 if self.external_vcc else 0x14
precharge = 0x22 if self.external_vcc else 0xf1
multiplex = 0x1f if self.height == 32 else 0x3f
compins = 0x02 if self.height == 32 else 0x12
contrast = 0xff # 0x8f if self.height == 32 else (0x9f if self.external_vcc else 0x9f)
data = [DISPLAYOFF,
SETDISPLAYCLOCKDIV, 0x80,
SETMULTIPLEX, multiplex,
SETDISPLAYOFFSET, 0x00,
SETSTARTLINE | 0x00,
CHARGEPUMP, chargepump,
MEMORYMODE, 0x00,
SEGREMAP | 0x10,
COMSCANDEC,
SETCOMPINS, compins,
SETCONTRAST, contrast,
SETPRECHARGE, precharge,
SETVCOMDETECT, 0x40,
DISPLAYALLON_RESUME,
NORMALDISPLAY,
DISPLAYON]
for item in data:
self.write_command(item)
self.clear()
self.display()
def poweron(self):
if self.offset == 1:
pyb.delay(10)
else:
self.res.high()
pyb.delay(1)
self.res.low()
pyb.delay(10)
self.res.high()
pyb.delay(10)
def poweroff(self):
self.write_command(DISPLAYOFF)
def contrast(self, contrast):
self.write_command(SETCONTRAST)
self.write_command(contrast)
def draw_text(self, x, y, string, size=1, space=1):
def pixel_x(char_number, char_column, point_row):
char_offset = x + char_number * size * font.cols + space * char_number
pixel_offset = char_offset + char_column * size + point_row
return self.columns - pixel_offset
def pixel_y(char_row, point_column):
char_offset = y + char_row * size
return char_offset + point_column
def pixel_mask(char, char_column, char_row):
char_index_offset = ord(char) * font.cols
return font.bytes[char_index_offset + char_column] >> char_row & 0x1
pixels = (
(pixel_x(char_number, char_column, point_row),
pixel_y(char_row, point_column),
pixel_mask(char, char_column, char_row))
for char_number, char in enumerate(string)
for char_column in range(font.cols)
for char_row in range(font.rows)
for point_column in range(size)
for point_row in range(1, size + 1))
for pixel in pixels:
self.set_pixel(*pixel)
