SSD1331 ¶

Contents

SSD1331

#include <eglib/display/ssd1331.h>

SSD1331_WIDTH¶: Display width

SSD1331_HEIGHT¶: Display height

Types ¶

enum ssd1331_column_address_mapping¶

Column address mapping.

SSD1331_RAM_COLUMN_0_TO_95_MAPS_TO_PIN_SEG_0_TO_95¶: RAM Column 0 to 95 maps to Pin Seg (SA,SB,SC) 0 to 95.

SSD1331_RAM_COLUMN_0_TO_95_MAPS_TO_PIN_SEG_95_TO_0¶: RAM Column 0 to 95 maps to Pin Seg (SA,SB,SC) 95 to 0.

enum ssd1331_com_scan¶

COM scan (where N is the multiplex ratio).

SSD1331_SCAN_FROM_COM0_TO_COM_N_1¶: Scan from COM0 to COM[N-1].

SSD1331_SCAN_FROM_COM_N_1_TO_COM0¶: Scan from COM[N-1] to COM0.

enum ssd1331_color_format¶

Color format.

SSD1331_256_COLORS¶: 256 color.

SSD1331_65k_COLORS¶: 65k color.

enum ssd1331_display_mode¶

Display mode.

SSD1331_DISPLAY_MODE_NORMAL¶: Normal display

SSD1331_DISPLAY_MODE_ENTIRE_DISPLAY_ON¶: Entire display ON, all pixels turn ON at GS63.

SSD1331_DISPLAY_MODE_ENTIRE_DISPLAY_OFF¶: Entire display OFF, all pixels turn OFF.

SSD1331_DISPLAY_MODE_INVERSE¶: Inverse display.

Configuration ¶

ssd1331_config_t¶

Configuration for ssd1331.

See also: eglib_Init().

uint8_t color_a_contrast¶: Contrast for color “A” segment (Pins: SA0-SA95). RESET=128.

uint8_t color_b_contrast¶: Contrast for color “B” segment (Pins: SA0-SA95). RESET=128.

uint8_t color_c_contrast¶: Contrast for color “C” segment (Pins: SA0-SA95). RESET=128.

uint8_t second_pre_charge_speed_for_color_a¶: Second pre-charge speed for color A. Default value equals to color_a_contrast.

uint8_t second_pre_charge_speed_for_color_b¶: Second pre-charge speed for color B. Default value equals to color_b_contrast.

uint8_t second_pre_charge_speed_for_color_c¶: Second pre-charge speed for color C. Default value equals to color_c_contrast.

enum ssd1331_column_address_mapping column_address_mapping¶: Column address mapping (mirror horizontally).

_Bool left_right_swapping_on_com¶: Left-right swapping on COM.

enum ssd1331_com_scan com_scan¶: COM scan (mirror vertically).

_Bool com_split_odd_even¶: COM split odd even.

enum ssd1331_color_format color_format¶: Color format. If 9/18bit mode is selected, color depth will be fixed to 65k.

uint8_t display_offset¶: Mapping of display start line to one of COM0-63.

uint8_t phase1_period¶: Phase 1 period in N DCLK (1-15). RESET=7.

uint8_t phase2_period¶: Phase 2 period in N DCLK (1-15). RESET=4.

uint8_t clock_divider¶: Divide ratio (D) of the display clocks (DCLK (1-16)). RESET=0.

uint8_t oscillator_frequency¶: Fosc frequency. RESET=13.

uint8_t * grayscale_table¶

When set to NULL, use linear gray scale table.

When set to not NULL, uses this gray scale table from GS1 to GS63.

uint8_t pre_charge_level¶: Set pre-charge voltage level from 0.10*Vcc (0) to 0x50*Vcc (31). RESET=31.

uint8_t v_comh¶: COM deselect voltage level (V COMH) from 0.44*Vcc (0) to 0.83*Vcc (31). RESET=3.

Pre-baked configurations ¶

ssd1331_config_t ssd1331_config_adafruit_65k_colors¶

Configuration for Adafruit OLED Breakout Board - 16-bit Color 0.96” w/microSD holder.

Values extracted from Adafruit’s example code.

Note: this configuration should work just fine with “generic” SSD1331 boards that can be easily found on eBay or Aliexpress.

ssd1331_config_t ssd1331_config_adafruit_256_colors¶: Variant of ssd1331_config_adafruit_65k_colors with only 256 colors instead of 65k.

ssd1331_config_t ssd1331_config_buydisplay_65k_colors¶

Configuration for Buy Display module.

Values extracted from Buy Display’s example code.

ssd1331_config_t ssd1331_config_buydisplay_256_colors¶: Variant of ssd1331_config_buydisplay_65k_colors with only 256 colors instead of 65k.

Driver ¶

const display_t ssd1331¶

SSD1331 display driver.

This driver supports the following data buses:

4-Wire SPI.

See also: eglib_Init().
See also: Datasheet.

const display_t ssd1331_overclock¶: Variant of ssd1331 which sets the SPI bus to 21.27Mhz. The datasheet states that the maximum bus speed is 6.66MHz, so mileage may vary when using this.

Functions ¶

These functions can be used exclusively with eglib_t initialized with ssd1331 or ssd1331_overclock.

void ssd1331_SetMasterCurrent(eglib_t * eglib, uint8_t value)¶

Set master current attenuation factor from 0 (1/16) to 15 (16/16).

This effectively controls the how dim / bright the display is.

void ssd1331_SetDisplayStartLine(eglib_t * eglib, uint8_t line)¶

Set the display start line from 0 to 63.

This controls vertical scrolling.

void ssd1331_SetDisplayMode(eglib_t * eglib, enum ssd1331_display_mode mode)¶: Set display mode

void ssd1331_SetDimMode(eglib_t * eglib, uint8_t color_a_contrast, uint8_t color_b_contrast, uint8_t color_c_contrast, uint8_t pre_charge_voltage)¶

Set Dim mode.

Parameters

color_a_contrast – Contrast setting for color A.
color_b_contrast – Contrast setting for color B.
color_c_contrast – Contrast setting for color C.
pre_charge_voltge – Precharge voltage setting (0-31). Setting this to~15 should keep contrast tame with for low contrast values.

void ssd1331_DrawLine(eglib_t * eglib, uint8_t x1, uint8_t y1, uint8_t x2, uint8_t y2)¶: Similar to eglib_DrawLine(), draw a line using color from index 0. It draws directly to display memory using a graphic accelerated command. Coordinates must be inside the display area.

void ssd1331_DrawFrame(eglib_t * eglib, coordinate_t x, coordinate_t y, coordinate_t width, coordinate_t height)¶: Similar to eglib_DrawFrame(), draw a frame using color from index 0. It draws directly to display memory using a graphic accelerated command. Coordinates must be inside the display area.

void ssd1331_DrawBox(eglib_t * eglib, coordinate_t x, coordinate_t y, coordinate_t width, coordinate_t height)¶: Similar to eglib_DrawBox(), draw a box using color from index 0. It draws directly to display memory using a graphic accelerated command. Coordinates must be inside the display area.

Examples ¶

4-Wire SPI ¶

#include <eglib.h>
#include <eglib/display/frame_buffer.h>
#include <eglib/display/ssd1331.h>
#include <eglib/hal/four_wire_spi/libopencm3_stm32f4.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/spi.h>
#include <stdio.h>

int main(void) {
	eglib_t eglib;
	eglib_t *eglib_ssd1331;

	four_wire_spi_libopencm3_stm32f4_config_t  four_wire_spi_libopencm3_stm32f4_config = {
		// rst
		.rcc_rst = RCC_GPIOA,
		.port_rst = GPIOA,
		.gpio_rst = GPIO4,
		// cd
		.rcc_dc = RCC_GPIOA,
		.port_dc = GPIOA,
		.gpio_dc = GPIO3,
		// cs
		.rcc_cs = RCC_GPIOA,
		.port_cs = GPIOA,
		.gpio_cs = GPIO2,
		// spi
		.rcc_spi = RCC_SPI1,
		.spi = SPI1,
		// sck
		.rcc_sck = RCC_GPIOA,
		.port_sck = GPIOA,
		.gpio_sck = GPIO5,
		// mosi
		.rcc_mosi = RCC_GPIOA,
		.port_mosi = GPIOA,
		.gpio_mosi = GPIO7,
	};
	rcc_clock_setup_pll(&rcc_hse_25mhz_3v3[RCC_CLOCK_3V3_84MHZ]);

	eglib_Init(
		&eglib,
		&four_wire_spi_libopencm3_stm32f4, &four_wire_spi_libopencm3_stm32f4_config,
		&ssd1331, &ssd1331_config_buydisplay_65k_colors
	);

	for(uint16_t y=0;y<SSD1331_HEIGHT;y++) {
		uint8_t v;
		v = y / ((float)SSD1331_HEIGHT-1) * 255;
		eglib_SetIndexColor(&eglib, 0, v, v, v);
		eglib_DrawLine(&eglib,0, y, SSD1331_WIDTH, y);
	}

	eglib_SetIndexColor(&eglib, 0, 255, 255, 255);
	eglib_DrawVLine(&eglib, SSD1331_WIDTH/2, 0, SSD1331_HEIGHT);

	eglib_SetIndexColor(&eglib, 0, 255, 0, 0);
	eglib_DrawLine(&eglib, 0, 0, SSD1331_WIDTH-1, SSD1331_HEIGHT/2);

	eglib_SetIndexColor(&eglib, 0, 0, 255, 0);
	eglib_DrawLine(&eglib,0, 0, SSD1331_WIDTH-1, SSD1331_HEIGHT-1);

	eglib_SetIndexColor(&eglib, 0, 0, 0, 255);
	eglib_DrawLine(&eglib,0, 0, SSD1331_WIDTH/2, SSD1331_HEIGHT-1);

	// Accelerated versions

	eglib_SetIndexColor(&eglib, 0, 0, 255, 255);
	ssd1331_DrawLine(&eglib, 0, 63, 95, 0);

	eglib_SetIndexColor(&eglib, 0, 255, 255, 0);
	ssd1331_DrawFrame(&eglib, 10, 20, 10, 20);

	eglib_SetIndexColor(&eglib, 0, 255, 0, 255);
	ssd1331_DrawFrame(&eglib, 0, 16, 95, 32);

	eglib_SetIndexColor(&eglib, 0, 255, 255, 255);
	ssd1331_DrawBox(&eglib, 40, 20, 40, 20);

	eglib_SetIndexColor(&eglib, 0, 0, 0, 0);
	ssd1331_DrawFrame(&eglib, 22, 20, 10, 20);
}