Hi Jan, thanks for your comment. I did figure out the need to attribut an unused pin to the RST pin as stated in * Displaying Text on a SSD1306 Oled display - Mbed OS / Hello world! - Arm Mbed OS support forum comment, however, the display is still black. no caracter showing up. I put a blink routine inside main() function and is working but I could not find why it is not displaying any character.
Regards, Alfredo
