Arduino Pro Micro 32U4 and oled.clear();

[GeoX234]

Hi,
I run a little serial modbus on an Arduino, which is connected as slave to a desktop PC. The Arduino is fitted with a small Oled display and a rotary encoder with push button. The rotary encoder is used to scroll through a menu and to make settings with the push button. Turning the encoder or pushing down his button will call oled.clear(), move menu items and print new menu item on the display. Modbus communication works perfect on an Arduino Nano with Atmel 328p.

BUT on an Arduino Pro Micro with Atmel 32U4 I run into problems. On an Atmel 32U4, after I called oled.clear(), some unwanted random output happens on the serial connection which interferes with the modbus communication. When I remove the call oled.clear(), modbus output of the slave works without "noise" but the display is od course messy....

Any idea or explanation why the call oled.clear() triggers some "noise" on the serial output of an Atmel 32U4 ?

Thank's

[greiman]

I have no idea what is happening.