CircuitPython version

7.0.0 latest, easily visible on MacroPad

Code/REPL

# code.py could be as simple as:
import time

i = 0
while True:
    print(i, "some text")
    i += 1
    time.sleep(0.1)

Behavior

The MacroPad display can become garbled if the code above is run, and then interrupted with ctrl-C, and then restarted with ctrl-D. Trash will appear on the right side of the display. Other more display-intensive programs can cause worse problems, like upside-down text, part of screen showing quickly-changing flickering text, etc.

Description

I have a hunch this is due to SPI display transactions being interruptible by ctrl-C. This code allows them to be interrupted:

The interruptions probably allow junk to be sent to the display: data interpreted as commands, etc. Perhaps this is in combination with the D/C line getting out of sync.

May be related to adafruit/Adafruit_CircuitPython_DisplayIO_SH1106#3.

Additional information

From @kattni (different display garbling from a different program):

Animation: https://cdn.discordapp.com/attachments/327298996332658690/862041401708904468/macropad_display_glitch.gif