The 72x40 OLED requires selecting the internal IREF, as opposed to the
default external IREF. This is an undocumented feature in the SSD1306
datasheet, but is present in the SSD1315 datasheet. It's possible the
72x40 OLED is actually using the newer SSD1315 controller. Sending the
IREF select command to SSD1306 displays has no effect on them, so it's
added to the init_display() instead of wrapping in an "if width = 72".
Also tested on a 128x64 OLED using the SSD1315 controller (smaller ribbon
cable) and the proposed change has no effect on the display, as the module
comes with the correct current limiting resistor. Internal and external
IREF work the same.
Fixes issue #7281.
Making it more specific to use 0x02 for display with an aspect ratio > 2
(resolutions 96x16 and 128x32) and 0x12 for all other sizes as recommended
by @mcauser. Tested with a 64x32 display which did not work before.
The poweroff() and poweron() methods are used to do soft power control of
the display, and this patch makes these methods work the same for both I2C
and SPI interfaces.
It removes the need for a wrapper Python function to dispatch to the
framebuf method which makes each function call a bit faster, roughly 2.5x.
This patch also adds the rest of the framebuf methods to the SSD class.
In particular, the WeMOS D1 Mini board comes with a shield that has a
64x48 OLED display. This patch makes it display properly, with the upper
left pixel being at (0, 0) and not (32, 0).
I tried to do this with the configuration commands, but there doesn't
seem to be a command that would set the column offset (there is one for
the line offset, though).
Mike Causer