Here a solution for ST7567S with I2C interface.

RP2040 based microcontroller boards running MicroPython.
Target audience: MicroPython users with an RP2040 boards.
This does not include conventional Linux-based Raspberry Pi boards.
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mcGeorge
Posts: 2
Joined: Sun Jul 17, 2022 1:45 am

Here a solution for ST7567S with I2C interface.

Post by mcGeorge » Mon Jul 18, 2022 4:01 pm

Hi @all,

after a long time of looking for a solution for my display, I created my own. I took an existing lib and adjusted it for this display and the I2C interface for MicroPython. Only a starter, but it works. By the way, I bought the display at Aliexpress, seeking for "12864 IIC LCD Module 128X64 I2C ST7567S COG Graphic Display Screen Board LCM Panel 128x64 Dot Matrix Screen for Arduino"

This is for everyone with the same problem.

Georg

/lcd-test.py

Code: Select all

from ST7567 import ST7567

C_SDA = const(4)
C_SCL = const(5)
sda_pin = machine.Pin(C_SDA)
scl_pin = machine.Pin(C_SCL)
i2c = machine.I2C(0, sda=sda_pin, scl=scl_pin, freq=100000)

oled = ST7567( 128, 64, i2c )
oled.set_contrast(25)
oled.text("1234567890123456", 0, 00)
oled.text("2345678901234567", 0, 10)
oled.text("3456789012345678", 0, 20)
oled.text("4567890123456789", 0, 30)
oled.text("5678901234567890", 0, 40)
oled.text("5678901234567890", 0, 50)
oled.text("6789012345678901", 0, 60)
oled.show()
/lib/ST7567.py

Code: Select all

#
# MIT License
#
# 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.

from micropython import const
from time import sleep_ms
import framebuf

# LCD Commands definition
CMD_DISPLAY_ON          = const(0xAF)
CMD_DISPLAY_OFF         = const(0xAE)
CMD_SET_START_LINE      = const(0x40)
CMD_SET_PAGE            = const(0xB0)
CMD_COLUMN_UPPER        = const(0x10)
CMD_COLUMN_LOWER        = const(0x00)
CMD_SET_ADC_NORMAL      = const(0xA0)
CMD_SET_ADC_REVERSE     = const(0xA1)
CMD_SET_COL_NORMAL      = const(0xC0)
CMD_SET_COL_REVERSE     = const(0xC8)
CMD_SET_DISPLAY_NORMAL  = const(0xA6)
CMD_SET_DISPLAY_REVERSE = const(0xA7)
CMD_SET_ALLPX_ON        = const(0xA5)
CMD_SET_ALLPX_NORMAL    = const(0xA4)
CMD_SET_BIAS_9          = const(0xA2)
CMD_SET_BIAS_7          = const(0xA3)
CMD_DISPLAY_RESET       = const(0xE2)
CMD_NOP                 = const(0xE3)
CMD_TEST                = const(0xF0)  # Exit this mode with CMD_NOP
CMD_SET_POWER           = const(0x28)
CMD_SET_RESISTOR_RATIO  = const(0x20)
CMD_SET_VOLUME          = const(0x81)

# Display parameters
DISPLAY_W               = const(128)
DISPLAY_H               = const(64)
DISPLAY_CONTRAST        = const(0x1B)
DISPLAY_RESISTOR_RATIO  = const(5)
DISPLAY_POWER_MODE      = 7


class ST7567(framebuf.FrameBuffer):

    def __init__(self, width, height, i2c, addr=0x3F, external_vcc=False):
        self.i2c          = i2c
        self.addr         = addr
        self.temp         = bytearray(2)
        self.write_list   = [b"\x40", None]  # Co=0, D/C#=1
        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.display_init()

    def display_init(self):
        self.write_cmd( CMD_DISPLAY_RESET )
        sleep_ms(1)
        for cmd in (
            CMD_DISPLAY_OFF,                                  # Display off
            CMD_SET_BIAS_9,                                   # Display drive voltage 1/9 bias
            CMD_SET_ADC_NORMAL,                               # Normal SEG
            CMD_SET_COL_REVERSE,                              # Commmon mode reverse direction
            CMD_SET_RESISTOR_RATIO + DISPLAY_RESISTOR_RATIO,  # V5 R ratio
            CMD_SET_VOLUME,                                   # Contrast
            DISPLAY_CONTRAST,                                 # Contrast value
            CMD_SET_POWER + DISPLAY_POWER_MODE):
            self.write_cmd(cmd)

        self.show()
        self.write_cmd(CMD_DISPLAY_ON)

    def set_contrast(self, value):
        if (0x1 <= value <= 0x3f):
            for cmd in ( CMD_SET_VOLUME, value ):
                self.write_cmd(cmd)

    def show(self):
        for i in range(8):
            for cmd in (
                CMD_SET_START_LINE,
                CMD_SET_PAGE + i,
                CMD_COLUMN_UPPER,
                    CMD_COLUMN_LOWER):
                self.write_cmd(cmd)
            self.write_data( self.buffer[i*128:(i+1)*128] )
            
    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 )


tepalia02
Posts: 99
Joined: Mon Mar 21, 2022 5:13 am

Re: Here a solution for ST7567S with I2C interface.

Post by tepalia02 » Tue Jul 19, 2022 3:08 am

Thank you very much. Many of us find it difficult to create a new library or edit one. This will certainly help many in need.

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