Flicker on SSD1306 Display

[phippstech]

Hi,

I'm currently working on a project that I want to display a "Setting", an angle, and symbol (up arrow, down arrow and check mark) at the same time (the value of the angle will change and when the value is in a certain threshold, the symbol will change). We have managed to get the "setting and angle" displaying but the symbol flashes through at different times. The text will also flicker at the same time of the delay that is built in my accelerometer code.
I guess our question is the flicker completely from the delay from the accelerometer and is there a work-around for that. Attached is the source code
Many thanks!
DKS_SC_V3.txt

[olikraus]

With u8x8 try to avoid clear screen. Instead overwrite existing values directly.

[phippstech]

Thanks, we will comment out every ".cleardisplay" command and see what that does. I thought that was the first thing I did when I started debugging this but we will give it another shot thanks.

[phippstech]

Unfortunately, by avoiding the clear screen function, the flashing was still there and since it wasn't clearing the screen there was 'remnants' of previous pixels between the angle number and symbol. Then, we tried setting the font and display the action, whether it was 'shaving,' 'slicing,' etc., once for each case since the only thing that would need to change was the angle number and the symbols. Well... this made the problem worse by displaying incorrectly. The thing that's strange is that the screen doesn't flicker with the "Sharp Pebble" followed by a 2.5 second delay but it does flicker for all the display functions in the 'void oled()' function. We also tried setting short delays after the last .draw1x2string() in each if() statement but that did not help. I can also provide video of the issue if it helps. Thanks!

[phippstech]

We have avoided using the clear screen function and that resolved part of the 'flickering'. The only issue is that whenever the angle display is in the double digits and then goes down to single digits, there's a 'remnant' of whatever the second digit was. For example, going from '22' degrees down to '4' degrees, the screen will show '42.'

Now, when displaying both the type of action, angle number, and arrow/check the flicker comes back. We have narrowed it down to the arrow display. Just displaying the arrow and nothing else, the screen is 'cleared' whenever the program executes the arrow display code causing it to clear repeatedly like a 'flicker'. Furthermore, by displaying the three actions together the 'flicker' effect returns as the arrow display 'clears' the entire screen as it executes in a loop.

What would you recommend to only 'clear' a certain cursor location to prevent incorrect angle quantities and how to prevent the arrow display from 'clearing' screen?

The code for the display:
`

    const char arrow_up[] = {67,'/0'};
    const char arrow_down[] = {64,'/1'};
    const char check[] = {64,'/0'};

//Set Cursor for up or down arrow and Check mark    
    u8x8.setFont(u8x8_font_open_iconic_arrow_4x4);
    u8x8.setCursor(12,1);
    u8x8.print(arrow_up);
//Set Font for mode and angle 
    u8x8.setFont(u8x8_font_8x13B_1x2_r);
    u8x8.draw1x2String(0,0,"Shaving");
    u8x8.draw1x2String(8,0,bufferzadj);

`

[olikraus]

For example, going from '22' degrees down to '4' degrees, the screen will show '42.'

I usually solve this by adding a blank, which then overwrites the 2 from the previously printed 22.