avsa242/ssd130x-spin

P8X32A/Propeller, P2X8C4M64P/Propeller 2 driver object for SSD130x OLED displays

ssd130x-spin

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This is a P8X32A/Propeller 1, P2X8C4M64P/Propeller 2 driver object for the Solomon Systech SSD130x OLED display controller.

IMPORTANT: This software is meant to be used with the spin-standard-library (P8X32A) or p2-spin-standard-library (P2X8C4M64P). Please install the applicable library first before attempting to use this code, otherwise you will be missing several files required to build the project.

Salient Features

• I2C connection at up to approx 400kHz (unenforced) (NOTE: Datasheet specifies max I2C clock of 400kHz. May function at higher bus speeds. YMMV!)
• SPI connection at fixed 4MHz (P1), up to 10MHz (P2, unenforced) (NOTE: Datasheet specifies max SPI clock of 10MHz. May function at higher bus speeds. YMMV!)
• Supports 128x32 and 128x64 displays
• Display mirroring (horizontal and vertical)
• Display visibility modes: normal, inverted, all pixels on
• Variable contrast
• Low-level display control: Logic voltages, oscillator frequency, addressing mode, row/column mapping
• Supports display modules with or without discrete RESET pin
• Integration with the generic bitmap graphics library
• Buffered display or direct-to-display drawing (see 'Limitations' for direct-to-display)
• Hardware-accelerated scrolling (horizontal L/R, combined vertical and horizontal L/R)

Requirements

P1/SPIN1:

• spin-standard-library
• P1/SPIN1: 1 extra core/cog for the PASM I2C or SPI engine, as applicable
• graphics.common.spinh (provided by spin-standard-library)
• (WIDTH * HEIGHT) / 8 bytes of RAM for the display, if buffered mode is used (default)

P2/SPIN2:

• p2-spin-standard-library
• graphics.common.spin2h (provided by p2-spin-standard-library)
• (WIDTH * HEIGHT) / 8 bytes of RAM for the display, if buffered mode is used (default)

Compiler Compatibility

Processor	Language	Compiler	Backend	Status
P1	SPIN1	FlexSpin (6.8.0)	Bytecode	OK
P1	SPIN1	FlexSpin (6.8.0)	Native/PASM	OK
P2	SPIN2	FlexSpin (6.8.0)	NuCode	OK
P2	SPIN2	FlexSpin (6.8.0)	Native/PASM2	OK

(other versions or toolchains not listed are not supported, and may or may not work)

Hardware Compatibility

• SSD1306 (tested)
• SSD1309 (tested)

Limitations

• Doesn't support parallel interface-connected displays (currently unplanned)
• Unbuffered/Direct-draw operations are limited, due to the nature of serial 1bpp displays. Box(), Line(), Circle and Plot() aren't implemented.

ssd130x-spin's Issues

Add support for bufferless displays

Currently, the driver only operates using a framebuffer hosted on the Propeller. Add support for direct-to-display drawing.

address() should be split into discrete R/W methods

This really doesn't need to be crammed into one method and should be split into two for simplicity.
Rename address() to set_address() (with alias to the name address so existing code doesn't break) and move the read code to a new method get_address().

Handle other display sizes

The driver is currently hardcoded for 128x32 displays, though the controller supports up to 128x64, and other sizes are available. Implement a mechanism for runtime or compile-time display size selection.

Implement scrolling

The SSD1306 provides a mechanism for hardware-based horizontal and vertical scrolling of the display. Unrelated to the mostly-genericized software scrolling in the bitmap graphics library.

Support alternate slave address

The SSD1306 supports one optional alternate slave address. Provision Startx with one extra parameter to handle this.

Add support for different charge pump voltages

The display controller actually supports four different charge pump voltages, but currently only two are supported, and not exposed to the user. It's currently written more like 'enabled or disabled.'
It should also be renamed to something like ChargePumpVoltage().

Implement text rendering

Currently, the driver implements a few basic primitives (points, lines, circles) - implement text rendering using a RAM font and/or the Propeller-ROM font.