/* OLED_contrast() See "oled.h" for details of how to use this function.  */
void OLED_contrast(uint8_t color_contrast)
/* OLED_contrast() See "oled.h" for details of how to use this function.  */
void OLED_contrast(uint8_t color_contrast)
{
    uint8_t oled_contrast[] =
    {
        OLED_COMMAND_CODE, CMD_CONTRAST,
        OLED_COMMAND_CODE, CONTRAST_DEFAULT,
    };
    oled_contrast[3] = color_contrast;
    MSS_I2C_write( g_p_oled_i2c, OLED_SLAVE_ADDRESS, oled_contrast, sizeof(oled_contrast), MSS_I2C_RELEASE_BUS );
    MSS_I2C_wait_complete( g_p_oled_i2c );
}