ESP8266 Community Forum

but programm is running but display is black.... do i needd external voltage_?

OLEDs typically don't need a separate supply, but which type of display do you have?
Is it a SSD1306? Or other controller?
How is it connected to the ESP?

1achy wrote:I try example firmware with set font etc. but programm is running but display is black.... do i needd external voltage_?
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Did you tried the code provided here: Oled Driver example

Before running the driver example:
- proper identify your SDA and SCL lines. (try to use GPIO4 and 5)
- check that you have proper pullup resistors on the choosen SDA and SCL lines (4k7 is just fine)
- connect OLED display at Vcc (+3,3V), GND, SDA and SCL. Vcc and GND are the same as for the ESP module.
- run a scanbus() utility program to be sure that your OLED is connected OK and is working OK. Also identify the allocated I2C bus address for OLED Display.

If all from above OK, just run the test driver code provided in the link, use your own SDA, SCL and I2C address if not the same as in example.

Happy breadboarding,
TJ.