Support for Monochrome Displays

[DJDevon3]

Someone was having an issue with taking a screenshot with a monochrome display due to bitmap colorspace. There doesn't seem to be support for monochrome displays?

They were using a 128x128 Monochrome display I do not have one to test with.

Circuit Python SH1107 library

help-with-circuitpython discord discussion

[AbFarid]

Thank you, @DJDevon3, for opening this issue! It was I (⚡️) who was having the issue!

It's true, that I was originally using adafruit_bitmapsaver.save_pixels(), but upon further investigation, I can conclude that the root of the problem is likely the adafruit_displayio_sh1107 library (or displayio.Display).

The issue

When using SH1107.fill_row() (an extension of displayio.Display.fill_row()) it triggers the following error:
ValueError: Display must have a 16 bit colorspace.

The display in question indeed has a 1 bit colorspace:

class SH1107(displayio.Display):
def __init__(...):
    super().__init__(
            #...
            color_depth=1,
            #...

I am not sure whether SH1107.fill_row() should override displayio.Display.fill_row() or if the Display method itself needs modification.

Environment

• Adafruit CircuitPython 8.2.2 on 2023-07-31
• Adafruit Feather RP2040 Scorpio
• Adafruit Monochrome 1.12" 128x128 OLED Graphic Display
• Not sure which lib bundle, but it's probably the same as the CircuitPython version

[tannewt]

This looks like a core issue because it is a limitation of fill_row:

circuitpython/shared-bindings/displayio/Display.c

Line 479 in 70ce576

mp_raise_ValueError(translate("Display must have a 16 bit colorspace."));

I'll move the issue.