OLED LCD Display

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Description[edit]

See also Tutorial Display

We use ssd1306.py


How to connect it electrically[edit]

The display is connected to the I2C bus. The build in Display on the ESP32 is connected to pin 15 (SCL) and pin 4 (SDA). For another ESP32 we can connect an external display to these pins, too.

For the ESP8266 ESP-12F OLED and other ESP8266 the I2C bus is on GPIO5/Pin24 (SCL) and GPIO4/Pin16 (SDA).

How to control it in MicroPython[edit]

 1 from machine import Pin, I2C
 2 from ssd1306 import SSD1306_I2C
 3 
 4 i2c = I2C(scl=Pin(15), sda=Pin(4))
 5 pin16 = Pin(16, Pin.OUT)
 6 pin16.on()
 7 
 8 oled_width = 128
 9 oled_height = 64
10 oled = SSD1306_I2C(oled_width,oled_height,i2c)
11 
12 # switch the display off, but it's still active
13 oled.poweroff()
14 
15 # switch the display on again
16 oled.poweron()
17 
18 # contrast in range 0-255 (0=darker)
19 oled.contrast(contrast)
20 
21 # invert in True/False
22 oled.invert(invert)
23 
24 # content will be shown, has to be called when something changes
25 oled.show()
26 
27 
28 # Graphics
29 # fill the screen in color c (0=dark, 1=bright)
30 oled.fill(c)
31 
32 # set pixel at position x,y to color c
33 oled.pixel(x,y,c)
34 
35 # returns color of pixel x,y
36 oled.pixel(x,y)
37 
38 # draws a horizontal line from x,y, length=w in color c
39 oled.hline(x,y,w,c)
40 
41 # draws a vertical line from x,y, length=w in color c
42 oled.vline(x,y,w,c)
43 
44 # draws a line from x1,y1 to x2,y2 in color c
45 oled.line(x1,y1,x2,y2,c)
46 
47 # draws a rectangle at position x,y with width=w and height=h in color c
48 oled.rect(x,y,w,h,c)
49 
50 # draws a filled rectangle at position x,y with width=w and height=h in color c
51 oled.fill_rect(x,y,w,h,c)
52 
53 
54 # Text
55 # set text s at pixel x,y
56 oled.text(s,x,y,c)
57 
58 # line = line number (0-5)
59 # pos = horizontal position (0-15)
60 def text_line(text, line, pos=0):
61   x = 10*pos
62   y = line*11
63   oled.text(text,x,y)
64   oled.show()
65 
66 # don't forget to show!
67 oled.show()


DisplayPixel.PNG DisplayLinePos.PNG

A small Program in MicroPython[edit]

 1 from machine import Pin, I2C
 2 from ssd1306 import SSD1306_I2C
 3 
 4 i2c = I2C(scl=Pin(15), sda=Pin(4))
 5 pin16 = Pin(16, Pin.OUT)
 6 pin16.on()
 7 
 8 oled_width = 128
 9 oled_height = 64
10 oled = SSD1306_I2C(oled_width,oled_height,i2c)
11 
12 # line = line number (0-5)
13 # pos = horizontal position (0-15)
14 def text_line(text, line, pos=0):
15   x = 10*pos
16   y = line*11
17   oled.text(text,x,y)
18   oled.show()
19   
20 # set text
21 oled.text("Hello",0,0)
22 # horizontal line from x=10, y=50, length=70, color bright
23 oled.hline(10,50,70,1)
24 # display it
25 oled.show()
26 sleep(3)
27 
28 # delete all/ set all to dark
29 oled.fill(0)
30 # don't forget to show/display changes
31 oled.show()
32 sleep(1)
33 
34 # set new text
35 oled.text("Hi",0,0)
36 # filled rectangle at x=50, y=20, width=20, height=20, color bright
37 oled.fill_rect(50,20,20,20,1)
38 # inverts colors of display
39 oled.invert(True)
40 oled.show()

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Related Tutorial Videos[edit]

Writing to the OLED Display over I2C[edit]

In this video on youtube (22:00) we show how to write text to the OLED Display on the ESP32 module. We then show how to connect a poti to an analog input and display the value in a loop on the display: https://youtu.be/UbxwePvgX-U

Another Tutorial (in German) on writing to the OLED Display with some background[edit]

There is a tutorial with several parts at "the Die Hobbyelektroniker - Community" on Micropython with ESP32 https://community.hobbyelektroniker.ch/wbb/index.php?board/51-lektion-5-das-display/


Background[edit]

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