Leaderboard

Hi, In an other project I use Raystrar 4*20 oled display with f4discovery. At first it had similar strange behavior and the probelm was that the oled supplyed with 5V power while the driving data lines provides only about 3V high level due to the direct connection to the stm ports. The 3V is way below the datasheet specified input high level which is 0.9*VDD. My solution was to lower the 5V power to the oled by a diode, but somewhere a 22ohm resistor was suggested to the same problem. Hope this helps. Norbim