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Live Update of OLED module in Python

vandia

I know this is probably a beginner/no-brainer question about a command I just don't know, but:

 

I'm using the PIL(Python Image Library) to write to an OLED via I2C for a project.

I can write to it alright, but when I create a loop, it writes the new message OVER the old message, causing the 2 to overlap the 1, and so on.

How can I remove either the selected line, or just one character, to replace with an updating number?

 

Note, the i increment is just a placeholder for other numeric data, where I just really need to update what's after "Num" with replacing it, not creating a 1/2/3 overlapped abomination. I just, with my still learning python, figured rewriting the line several numbers will be updated on, would be the easiest remedy.

 

My Code

def numbers():

    for i in range(int(11)):

        print(i)

 

 

  draw.text((0, top-8)," Num:"+str(i),  font=ImageFont.truetype("fonts/arial.otf", 17), fill=255)

  disp.image(image)

  disp.display()

 

 

  time.sleep(2)

 

I know this is outside typical e14 posts, but since it's an I2C(IoT) module that can work for BeagleBone, Raspberry Pi, and the Edison (anything that can run Python on I2C), but  I felt it appropriate to ask here how to make it work (compared to some unnamed sites where asking a noob programming question gets you ostracized).

  • I spent more time playing with it and ideas to get it to work. I tried calling disp.clear ( where disp = SSD1306.SSD1306_128_64() )  within the loop, but no luck.

     

    An article on the Arduino forums HERE explained a typical way of doing it, that's not actually exclusive to Python.

    In short, it was to write over the old test you're wanting to replace with the background color... which is monochrome for most OLEDs. So, Fill=0 vs Fill=255 in Python. If you call to write over the old OLED message with the same exact one but in the former color, and do so before the next cycle (message change), it will remove what it just put.

     

    I've still yet to figure out how to properly make .clear() work on this model, but here is the correction to the code I had, in case anyone else may need:

     

    def numbers():

      for i in range(int(11)):

       print(i)

      draw.text((0, top-8)," Core:"+str(i),  font=font, fill=255)

      # Display image.

      disp.image(image)

      disp.display()

      time.sleep(2)

      #remove old image before next cycle

      draw.text((0, top-8)," Core:"+str(i),  font=font, fill=0)

  • in reply to vandia

    8 years late but this helped me. Thank you.