Python - OLED 128x64 Bricklet

This is the description of the Python API bindings for the OLED 128x64 Bricklet. General information and technical specifications for the OLED 128x64 Bricklet are summarized in its hardware description.

An installation guide for the Python API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Hello World

Download (example_hello_world.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your OLED 128x64 Bricklet

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_oled_128x64 import BrickletOLED128x64

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    oled = BrickletOLED128x64(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Clear display
    oled.clear_display()

    # Write "Hello World" starting from upper left corner of the screen
    oled.write_line(0, 0, "Hello World")

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

Pixel Matrix

Download (example_pixel_matrix.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change XYZ to the UID of your OLED 128x64 Bricklet
WIDTH = 128 # Columns (each 1 pixel wide)
HEIGHT = 8 # Rows (each 8 pixels high)

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_oled_128x64 import BrickletOLED128x64

def draw_matrix(oled, start_column, start_row, column_count, row_count, pixels):
    pages = []

    # Convert pixel matrix into 8bit pages
    for row in range(row_count):
        pages.append([])

        for column in range(column_count):
            page = 0

            for bit in range(8):
                if pixels[(row * 8) + bit][column]:
                    page |= 1 << bit

            pages[row].append(page)

    # Merge page matrix into single page array
    data = []

    for row in range(row_count):
        for column in range(column_count):
            data.append(pages[row][column])

    # Set new window
    oled.new_window(start_column, start_column + column_count - 1,
                    start_row, start_row + row_count - 1)

    # Write page data in 64 byte blocks
    for i in range(0, len(data), 64):
        block = data[i:i + 64]
        oled.write(block + [0] * (64 - len(block)))

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    oled = BrickletOLED128x64(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Clear display
    oled.clear_display()

    # Draw checkerboard pattern
    pixels = []

    for row in range(HEIGHT * 8):
        pixels.append([])

        for column in range(WIDTH):
            pixels[row].append((row // 8) % 2 == (column // 8) % 2)

    draw_matrix(oled, 0, 0, WIDTH, HEIGHT, pixels)

    raw_input("Press key to exit\n") # Use input() in Python 3
    ipcon.disconnect()

Load Image

Download (example_load_image.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change to your UID
WIDTH = 128 # Columns (each 1 pixel wide)
HEIGHT = 8 # Rows (each 8 pixels high)

import sys
from PIL import Image
from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_oled_128x64 import BrickletOLED128x64

def draw_matrix(oled, start_column, start_row, column_count, row_count, pixels):
    pages = []

    # Convert pixel matrix into 8bit pages
    for row in range(row_count):
        pages.append([])

        for column in range(column_count):
            page = 0

            for bit in range(8):
                if pixels[(row * 8) + bit][column]:
                    page |= 1 << bit

            pages[row].append(page)

    # Merge page matrix into single page array
    data = []

    for row in range(row_count):
        for column in range(column_count):
            data.append(pages[row][column])

    # Set new window
    oled.new_window(start_column, start_column + column_count - 1,
                    start_row, start_row + row_count - 1)

    # Write page data in 64 byte blocks
    for i in range(0, len(data), 64):
        block = data[i:i + 64]
        oled.write(block + [0] * (64 - len(block)))

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    oled = BrickletOLED128x64(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Clear display
    oled.clear_display()

    # Convert image to black/white pixels
    image = Image.open(sys.argv[1])
    image_data = image.load()
    pixels = []

    for row in range(HEIGHT * 8):
        pixels.append([])

        for column in range(WIDTH):
            if column < image.size[0] and row < image.size[1]:
                pixel = image_data[column, row] > 0
            else:
                pixel = False

            pixels[row].append(pixel)

    draw_matrix(oled, 0, 0, WIDTH, HEIGHT, pixels)

    raw_input('Press key to exit\n') # Use input() in Python 3
    ipcon.disconnect()

Scribble

Download (example_scribble.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

HOST = "localhost"
PORT = 4223
UID = "XYZ" # Change to your UID
WIDTH = 128 # Columns (each 1 pixel wide)
HEIGHT = 8 # Rows (each 8 pixels high)

import math
import time
from PIL import Image, ImageDraw
from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_oled_128x64 import BrickletOLED128x64

def draw_image(oled, start_column, start_row, column_count, row_count, image):
    image_data = image.load()
    pages = []

    # Convert image pixels into 8bit pages
    for row in range(row_count):
        pages.append([])

        for column in range(column_count):
            page = 0

            for bit in range(8):
                if image_data[column, (row * 8) + bit]:
                    page |= 1 << bit

            pages[row].append(page)

    # Merge page matrix into single page array
    data = []

    for row in range(row_count):
        for column in range(column_count):
            data.append(pages[row][column])

    # Set new window
    oled.new_window(start_column, start_column + column_count - 1,
                    start_row, start_row + row_count - 1)

    # Write page data in 64 byte blocks
    for i in range(0, len(data), 64):
        block = data[i:i + 64]
        oled.write(block + [0] * (64 - len(block)))

if __name__ == "__main__":
    ipcon = IPConnection() # Create IP connection
    oled = BrickletOLED128x64(UID, ipcon) # Create device object

    ipcon.connect(HOST, PORT) # Connect to brickd
    # Don't use device before ipcon is connected

    # Clear display
    oled.clear_display()

    # Draw rotating line
    image = Image.new("1", (WIDTH, HEIGHT * 8), 0)
    draw = ImageDraw.Draw(image)
    origin_x = WIDTH // 2
    origin_y = HEIGHT * 8 // 2
    length = HEIGHT * 8 // 2 - 2
    angle = 0

    print("Press ctrl+c to exit")

    try:
        while True:
            radians = math.pi * angle / 180.0
            x = (int)(origin_x + length * math.cos(radians))
            y = (int)(origin_y + length * math.sin(radians))

            draw.rectangle((0, 0, WIDTH, HEIGHT * 8), 0, 0)
            draw.line((origin_x, origin_y, x, y), 1, 1)

            draw_image(oled, 0, 0, WIDTH, HEIGHT, image)
            time.sleep(0.025)

            angle += 1
    except KeyboardInterrupt:
        pass

    ipcon.disconnect()

Draw Servo Poti

Download (example_draw_servo_poti.py)

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#!/usr/bin/env python
# -*- coding: utf-8 -*-

#
# This example uses a Servo Brick, a Rotary Poti Bricklet and
# a OLED 128x64 Bricklet.
#
# The position of the Rotary Poti Bricklet is drawn on the OLED
# display (as text, as a bar graph and as a dial indicator).
# At the same time the servo moves to an angle that is equivalent
# of the position of the Rotary Poti Bricklet.
#

HOST = "localhost"
PORT = 4223
SCREEN_WIDTH = 128
SCREEN_HEIGHT = 64

from tinkerforge.ip_connection import IPConnection
from tinkerforge.bricklet_oled_128x64 import BrickletOLED128x64
from tinkerforge.bricklet_rotary_poti import BrickletRotaryPoti
from tinkerforge.brick_servo import BrickServo

from PIL import Image, ImageDraw, ImageFont

import sys
import math
import time

def draw_matrix(pixels):
    column_index = 0
    column = []

    for i in range(SCREEN_HEIGHT//8 - 1): # We use last 8 pixels for text
        for j in range(SCREEN_WIDTH):
            page = 0
            for k in range(8):
                if pixels[i*8 + k][j] == 1:
                    page |= 1 << k

            if len(column) <= column_index:
                column.append([])

            column[column_index].append(page)
            if len(column[column_index]) == SCREEN_HEIGHT:
                column_index += 1

        oled.new_window(0, SCREEN_WIDTH-1, 0, 6)

    for i in range(len(column)):
        oled.write(column[i])

def line_at_angle(startx, starty, angle, length):
   radian_angle = math.pi * angle / 180.0
   x = startx + length * math.cos(radian_angle)
   y = starty + length * math.sin(radian_angle)
   return (startx, starty, x, y)

if __name__ == "__main__":
    # Create Brick/Bricklet objects
    ipcon = IPConnection()
    oled = BrickletOLED128x64('x5U', ipcon)
    poti = BrickletRotaryPoti('8Co', ipcon)
    servo = BrickServo('6e8MF1', ipcon)

    # Connect to brickd
    ipcon.connect(HOST, PORT)

    # Configure Servo so that it rotates 180°
    servo.set_pulse_width(6, 650, 2350)
    servo.enable(6)

    # Clear display
    oled.clear_display()

    # Draw text once at beginning, the window in draw_matrix does not overwrite
    # the last line of the display
    oled.write_line(7, 5, "tinkerforge.com")

    # We just use an endless loop here, press ctrl + c to abort the script
    while True:
        # With position 110 poti is at 90°
        angle = poti.get_position()*90//110
        if angle > 90:
            angle = 90
        elif angle < -90:
            angle = -90

        # Set servo position according to angle
        servo.set_position(6, angle*100)

        # Create angle text
        angle_str = str(angle) + u'°'
        if angle >= 0:
            angle_str = ' ' + angle_str

        # Draw servo position line
        img = Image.new('1', (128, 64), 0)
        draw = ImageDraw.Draw(img)
        draw.line(line_at_angle(32, 32, angle - 90, 32), 1, 6)

        # Draw bar graph
        draw.line((90, 4, 90 + angle*30//90, 4), 1, 6)

        # Draw angle text
        font = ImageFont.truetype("./share/fonts/truetype/dejavu/DejaVuSans.ttf", 25)
        draw.text((70, 22), angle_str, font=font, fill=1)

        # Move data from PIL image into matrix of bools
        data = img.load()
        pixel_matrix = [[False]*SCREEN_WIDTH for i in range(SCREEN_HEIGHT)]
        for x in range(SCREEN_WIDTH):
            for y in range(SCREEN_HEIGHT):
                pixel_matrix[y][x] = data[x, y] == 1

        # Draw everything to display
        draw_matrix(pixel_matrix)

        # Framerate of ~40 FPS
        time.sleep(0.04)

    ipcon.disconnect()

API

Generally, every method of the Python bindings can throw an tinkerforge.ip_connection.Error exception that has a value and a description property. value can have different values:

  • Error.TIMEOUT = -1
  • Error.ALREADY_CONNECTED = -7
  • Error.NOT_CONNECTED = -8
  • Error.INVALID_PARAMETER = -9
  • Error.NOT_SUPPORTED = -10
  • Error.UNKNOWN_ERROR_CODE = -11
  • Error.STREAM_OUT_OF_SYNC = -12

All methods listed below are thread-safe.

Basic Functions

BrickletOLED128x64(uid, ipcon)
Parameters:
  • uid -- string
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

oled_128x64 = BrickletOLED128x64("YOUR_DEVICE_UID", ipcon)

This object can then be used after the IP Connection is connected (see examples above).

BrickletOLED128x64.write(data)
Parameters:data -- [int, int, ..61x.., int]
Return type:None

Appends 64 byte of data to the window as set by new_window().

Each row has a height of 8 pixels which corresponds to one byte of data.

Example: if you call new_window() with column from 0 to 127 and row from 0 to 7 (the whole display) each call of write() (red arrow) will write half of a row.

Display pixel order

The LSB (D0) of each data byte is at the top and the MSB (D7) is at the bottom of the row.

The next call of write() will write the second half of the row and the next two the second row and so on. To fill the whole display you need to call write() 16 times.

BrickletOLED128x64.new_window(column_from, column_to, row_from, row_to)
Parameters:
  • column_from -- int
  • column_to -- int
  • row_from -- int
  • row_to -- int
Return type:

None

Sets the window in which you can write with write(). One row has a height of 8 pixels.

The columns have a range of 0 to 127 and the rows have a range of 0 to 7.

BrickletOLED128x64.clear_display()
Return type:None

Clears the current content of the window as set by new_window().

BrickletOLED128x64.write_line(line, position, text)
Parameters:
  • line -- int
  • position -- int
  • text -- str
Return type:

None

Writes text to a specific line (0 to 7) with a specific position (0 to 25). The text can have a maximum of 26 characters.

For example: (1, 10, "Hello") will write Hello in the middle of the second line of the display.

You can draw to the display with write() and then add text to it afterwards.

The display uses a special 5x7 pixel charset. You can view the characters of the charset in Brick Viewer.

Advanced Functions

BrickletOLED128x64.set_display_configuration(contrast, invert)
Parameters:
  • contrast -- int
  • invert -- bool
Return type:

None

Sets the configuration of the display.

You can set a contrast value from 0 to 255 and you can invert the color (black/white) of the display.

The default values are contrast 143 and inverting off.

BrickletOLED128x64.get_display_configuration()
Return type:(int, bool)

Returns the configuration as set by set_display_configuration().

The returned namedtuple has the variables contrast and invert.

BrickletOLED128x64.get_api_version()
Return type:[int, int, int]

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

BrickletOLED128x64.get_response_expected(function_id)
Parameters:function_id -- int
Return type:bool

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See set_response_expected() for the list of function ID constants available for this function.

BrickletOLED128x64.set_response_expected(function_id, response_expected)
Parameters:
  • function_id -- int
  • response_expected -- bool
Return type:

None

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

  • BrickletOLED128x64.FUNCTION_WRITE = 1
  • BrickletOLED128x64.FUNCTION_NEW_WINDOW = 2
  • BrickletOLED128x64.FUNCTION_CLEAR_DISPLAY = 3
  • BrickletOLED128x64.FUNCTION_SET_DISPLAY_CONFIGURATION = 4
  • BrickletOLED128x64.FUNCTION_WRITE_LINE = 6
BrickletOLED128x64.set_response_expected_all(response_expected)
Parameters:response_expected -- bool
Return type:None

Changes the response expected flag for all setter and callback configuration functions of this device at once.

BrickletOLED128x64.get_identity()
Return type:(str, str, chr, [int, int, int], [int, int, int], int)

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

The returned namedtuple has the variables uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Constants

BrickletOLED128x64.DEVICE_IDENTIFIER

This constant is used to identify a OLED 128x64 Bricklet.

The get_identity() function and the CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletOLED128x64.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a OLED 128x64 Bricklet.