Configuration¶

Every setting the driver takes: the construction-time configuration, the build options and the ESP32 example's Kconfig.

SmartDisplayConfig¶

Pass it to the constructor; it is fixed for the life of the SmartDisplay object.

const isf15acp4::SmartDisplayConfig config{
    .variant = isf15acp4::ProductVariant::Isf15acp4,
    .graphics = isf15acp4::GraphicsBackend::BuiltinCanvas,
    .enable_vcc_on_init = true,
};
isf15acp4::SmartDisplay<MySpi> display(&spi, config);
return display.Initialize(config.enable_vcc_on_init);

Field	Default	Meaning
`variant`	`Isf15acp4`	Init table, geometry and window (Hardware)
`graphics`	`BuiltinCanvas`	Backend of new graphics contexts (Graphics)
`enable_vcc_on_init`	`true`	Stored only: pass it to `Initialize()` yourself

The two-argument constructor SmartDisplay(bus, variant) uses the defaults for the rest.

Initialisation table¶

Initialize() sends the table for the variant from inc/isf15acp4_ssd1331.hpp. For the ISF15ACP4:

Command	Data	Sets
`81h`, `82h`, `83h`	`1Ch`, `2Eh`, `2Ch`	Contrast of colours A, B, C
`8Ah`, `8Bh`, `8Ch`	`4Fh`, `74h`, `88h`	Second pre-charge speed of A, B, C
`87h`	`0Fh`	Master current: maximum
`A0h`	`68h`	Remap: 65k colours, COM split and scan direction
`A1h`, `A2h`	`00h`, `00h`	Display start line, display offset
`A4h`		Normal display
`A8h`	`3Fh`	Multiplex ratio: 64 rows
`ABh`	`00h 0Eh 17h 16h 12h`	Dim mode contrast and pre-charge
`ADh`	`8Eh`	Master configuration: external VCC
`B0h`	`0Bh`	Power save off
`B1h`	`17h`	Phase 1 and 2 periods
`B3h`	`F0h`	Clock divider and oscillator frequency
`B9h`		Linear grey-scale table
`BBh`	`1Dh`	Pre-charge level
`BEh`	`20h`	V_COMH level
`AFh`		Display on

To change a value, for example the contrast, send the command after Initialize() through your own transaction (BeginCommand(), WriteBytes(), EndTransaction() on your port), or edit the table. The values come from NKK's programming guidance for this part; test any change on the panel.

CMake options¶

Both options default to OFF:

Option	Effect when `ON`
`HF_ISF15ACP4_ENABLE_WARNINGS`	`-Wall -Wextra -Wpedantic` on the driver
`HF_ISF15ACP4_BUILD_TESTS`	The host tests and the documentation snippets (Testing and CI)

ESP32 example Kconfig¶

The examples read their pins from menuconfig (HF ISF15ACP4 SmartDisplay), defined in Kconfig. Every symbol starts with CONFIG_ISF15ACP4_:

Symbol	Default	Signal
`SPI_HOST`	`1`	SPI2 (`2` is SPI3)
`PIN_MOSI`	`11`	SDI
`PIN_SCLK`	`12`	SCK
`PIN_CS`	`10`	SS, driven as a GPIO
`PIN_DC`	`13`	D/C
`PIN_RES`	`14`	RES
`PIN_VCC_EN`	`9`	Enable of the VCC supply
`PIN_SWITCH`	`8`	SW, pull-up, pressed reads low

The SPI clock is ISF15ACP4_SPI_CLOCK_HZ (6 MHz) in esp32_isf15acp4_test_config.hpp.

Next: Porting writes the port for your MCU.