Oled Display does'n work

[schalck25]

Moin zusammen, ich habe folgendes Problem:
Ich versuche seit geraumer Zeit ein Display (GJD 1602IIC) an einen ESP8266 anzuschließen um mir (später) Seonsordaten anzeigen zu lassen.
Ich scheitere jedoch schon an der Installation.
Ich habe folgendes geschalten:
Anschluss SCL (Display) an D2 des ESP
Anschluss SDA (Display) an D1 des ESP
Anschluss GND (Display) an GND des ESP und
Anschluss VCC (Display) an 3V des ESP

Ich versuche, ein Python-Testprogramm in der Thonny-Umgebung zum Laufen zu bringen.
Hier der Code:
from time import sleep_ms, ticks_ms
from machine import I2C, Pin
from esp8266_i2c_lcd import I2cLcd

i2c = I2C(scl=Pin(5), sda=Pin(4), freq=400000)

lcd = I2cLcd(i2c, 0x27, 2, 16)
lcd.putstr("Hello ernitron\nIt's working!")
lcd.clear()
lcd.putstr("Using dhylands\npython_lcd")

lcd = I2cLcd(i2c, 0x27, 4, 20)

lcd.putstr("WeMos D1 Mini with PCF8574 I2C backpackWorks with HD44780s:08x2 16x1 16x2 20x4")
lcd.clear()
lcd.putstr("line 1\nline 2\nline 3\nline 4")

Starte ich das Programm erhalte ich folgende Fehlermeldung:

File "", line 7, in
File "/lib/esp8266_i2c_lcd.py", line 25, in init

In Zeile 25 steht: self.i2c.writeto(self.i2c_addr, bytearray([0]))

Leider kann ich damit nichts anfangen. Kann mir jemand helfen ?
Vielen Dank schon mal im Voraus.
LG Schalck`

[robert-hh]

There most be more of an error message that just:

File "", line 7, in
File "/lib/esp8266_i2c_lcd.py", line 25, in init

But it looks like an wiring error. In case that you use an Wemos D1 Mini:
D1 is GPIO5
D2 is GPIO4
And so either you have to swap the SCD/SDA wires, or rewrite the I2c constructor to:
i2c = I2C(scl=Pin(4), sda=Pin(5), freq=400000)

Edit: b.t.w.: Its an LCD, and you cannot write more that 2 x 16 characters.

[schalck25]

Thanks for the rapid backcall. For a test i changed the SDA/SCL wires. And i changed the line "lcd.putstr("line 1\nline 2\nline 3\nline 4")" to lcd.putstr("line 1\nline 2"). Unfortunely it does not work.

[robert-hh]

Please try a scan on the I2C bus by calling:

from machine import I2C, Pin
i2c = I2C(scl=Pin(5), sda=Pin(4), freq=400000)
i2c.scan()

That should return a short list of decimal numbers, which are the addresses of the devices on the bus. It should contain 39 == 0x27. If it shows no number or many, the I2C bus wiring is still wrong. If it shows a different number, you may have to use that address in your code.

P.S.: To have a proper formatting of the code, include it in lines with three backticks ``` . As a shortcut you can select the code text and push Ctrl-E

[schalck25]

no empty list. only:

%Run -c $EDITOR_CONTENT

[robert-hh]

Looks like Thonny is hiding stuff. Try to run it without Thonny. You can paste these three lines directly into the REPL prompt.

[schalck25]

when i put the code into the REPL prompt i get the output: [63]

[robert-hh]

So the I2C address is 63 or 0x3F. Please use that one instead of 0x27.

[schalck25]

You are a hero. It works. Thank you for your held and i wish you a nice evening