Raspberry PiからSSD1306に画像を表示しよう[SSD1306の使い方]

/* SSD1306初期設定値 */
#define SSD1306_CONFIG_MUX_RATIO_CMD (0xA8)
#define SSD1306_CONFIG_MUX_RATIO_A (0x3F)
#define SSD1306_CONFIG_DISPLAY_OFFSET_CMD (0xD3)
#define SSD1306_CONFIG_DISPLAY_OFFSET_A (0x0)
#define SSD1306_CONFIG_DISPLAY_START_LINE (0x40)
#define SSD1306_CONFIG_SEGMENT_REMAP (0xA1)
#define SSD1306_CONFIG_COM_OUT_DIRECTION (0xC8)
#define SSD1306_CONFIG_COM_PIN_CONFIG_CMD (0xDA)
#define SSD1306_CONFIG_COM_PIN_CONFIG_A (0x12)
#define SSD1306_CONFIG_CONTRAST_CMD (0x81)
#define SSD1306_CONFIG_CONTRAST_A (0x7F)
#define SSD1306_CONFIG_ENTIRE_DISPLAY_ON (0xA4)
#define SSD1306_CONFIG_DISPLAY_PIX_MODE (0xA6)
#define SSD1306_CONFIG_DISPLAY_FREQ_CMD (0xD5)
#define SSD1306_CONFIG_DISPLAY_FREQ_A (0xF0)
#define SSD1306_CONFIG_ADDRESSING_MODE_CMD (0x20)
#define SSD1306_CONFIG_ADDRESSING_MODE_A (0x0)
#define SSD1306_CONFIG_CHARGE_PUMP_CMD (0x8D)
#define SSD1306_CONFIG_CHARGE_PUMP_A (0x14)
#define SSD1306_CONFIG_DISPLAY_ON_OFF (0xAF)

#define SSD1306_CTRL_BYTE_CMD_SINGLE (0b00000000)  //1つのコマンドセットのみ
#define SSD1306_CTRL_BYTE_CMD_STREAM (0b10000000)  //コマンドの後ろに続けて複数のコントロールバイト＆コマンドor描画データを場合（本モジュールでは使用しない）
#define SSD1306_CTRL_BYTE_DATA_SINGLE (0b01000000) //描画データのWriteのみ
#define SSD1306_CTRL_BYTE_DATA_STREAM (0b11000000) //描画データの後ろに続けて複数のコントロールバイト＆コマンドor描画データを場合（本モジュールでは使用しない）

/* 初期設定コマンドセット */
static const U08 U08_SSD1306_Init_Config[] = {
    SSD1306_CONFIG_MUX_RATIO_CMD,
    SSD1306_CONFIG_MUX_RATIO_A,
    SSD1306_CONFIG_DISPLAY_OFFSET_CMD,
    SSD1306_CONFIG_DISPLAY_OFFSET_A,
    SSD1306_CONFIG_DISPLAY_START_LINE,
    SSD1306_CONFIG_SEGMENT_REMAP,
    SSD1306_CONFIG_COM_OUT_DIRECTION,
    SSD1306_CONFIG_COM_PIN_CONFIG_CMD,
    SSD1306_CONFIG_COM_PIN_CONFIG_A,
    SSD1306_CONFIG_CONTRAST_CMD,
    SSD1306_CONFIG_CONTRAST_A,
    SSD1306_CONFIG_ENTIRE_DISPLAY_ON,
    SSD1306_CONFIG_DISPLAY_PIX_MODE,
    SSD1306_CONFIG_DISPLAY_FREQ_CMD,
    SSD1306_CONFIG_DISPLAY_FREQ_A,
    SSD1306_CONFIG_ADDRESSING_MODE_CMD,
    SSD1306_CONFIG_ADDRESSING_MODE_A,
    SSD1306_CONFIG_CHARGE_PUMP_CMD,
    SSD1306_CONFIG_CHARGE_PUMP_A,
    SSD1306_CONFIG_DISPLAY_ON_OFF,
};

/* -----------------------------------------------------------------------------
 Function   : Ssd1306_Init
 Memo       : SSD1306初期化
 Date       : 2021.08.28
------------------------------------------------------------------------------*/
BOOL Ssd1306_Init()
{
    BOOL status = OK;
    U08 cmd_buf[BUFSIZ];

    /* 動作設定 */
    cmd_buf[0] = SSD1306_CTRL_BYTE_CMD_SINGLE;
    U08 *p = &cmd_buf[1];
    for(U32 i=0; i < NUM_OF_SSD1306_CONFIG; i++)
    {
        *(p++) = U08_SSD1306_Init_Config[i];
    }
    Ssd1306_Write(cmd_buf, NUM_OF_SSD1306_CONFIG + 1);

    /* 画面初期化(黒塗り) */
    U08_Draw_Canvas_Payload[0] = SSD1306_CTRL_BYTE_DATA_SINGLE;
    Ssd1306_Write(U08_Draw_Canvas_Payload, SSD1306_DRAW_CANVAS_PAYLOAD_SIZE);

    return status;
}

cmd_buf[0] = SSD1306_CTRL_BYTE_CMD_SINGLE;   //0b00000000
~
U08_Draw_Canvas_Payload[0] = SSD1306_CTRL_BYTE_DATA_SINGLE;   //0b01000000

sudo apt install libjpeg-dev

$ make
gcc -Wall -Wextra  -o obj/./I2cCtl.o -c I2cCtl.c
gcc -Wall -Wextra  -o obj/./main.o -c main.c
gcc -Wall -Wextra  -o obj/./Ssd1306.o -c Ssd1306.c
gcc -o ./a.out obj/./I2cCtl.o obj/./main.o obj/./Ssd1306.o /usr/lib/arm-linux-gnueabihf/libjpeg.so

$ ./a.out

/* -----------------------------------------------------------------------------
 Function   : DrawTest
 Memo       : 
 Date       : 2021.09.25
------------------------------------------------------------------------------*/
void DrawTest()
{
	U08 *canvas = Ssd1306_Get_Draw_Canvas();
	canvas[0] = 0x0F;
	canvas[1] = 0x0F;
	canvas[2] = 0xF0;
	canvas[3] = 0xF0;
	canvas[4] = 0x0F;
	canvas[5] = 0x0F;
	canvas[6] = 0xF0;
	canvas[7] = 0xF0;
	Ssd1306_Update_Frame();
}

/* -----------------------------------------------------------------------------
 Function   : Ssd1306_Get_Draw_Canvas
 Memo       : キャンバスアドレス取得
 Date       : 2021.08.28
------------------------------------------------------------------------------*/
U08* Ssd1306_Get_Draw_Canvas()
{
    return U08p_Draw_Canvas;
}
/* -----------------------------------------------------------------------------
 Function   : Ssd1306_Update_Frame
 Memo       : 描画バッファをSSD1306に送信して画面更新
 Date       : 2021.08.28
------------------------------------------------------------------------------*/
void Ssd1306_Update_Frame()
{
    U08_Draw_Canvas_Payload[0] = SSD1306_CTRL_BYTE_DATA_SINGLE;
    Ssd1306_Write(U08_Draw_Canvas_Payload, SSD1306_DRAW_CANVAS_PAYLOAD_SIZE);
}

/* -----------------------------------------------------------------------------
 Function   : main
 Memo       : 
 Date       : 2021.09.25
------------------------------------------------------------------------------*/
int main()
{
	BOOL ret;

	/* 初期化 */
	ret = I2cCtl_Init();
	if (ret == NG)
	{
		printf("I2cCtl_Init Error.\n");
		return -1;
	}
	ret = Ssd1306_Init();
	if (ret == NG)
	{
		printf("Ssd1306_Init Error.\n");
		return -1;
	}

	/* 描画 */
	// DrawTest();
	DisplayImg();

	return 0;
}

$ make
$ ./a.out