display.c

/*
 * Copyright (c) 2018 PHYTEC Messtechnik GmbH
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#include <zephyr.h>
#include <device.h>
#include <display/cfb.h>
#include <stdio.h>

#include <logging/log.h>
LOG_MODULE_REGISTER(display, 3);

#define DISPLAY_DRIVER      DT_INST_0_SOLOMON_SSD1306FB_LABEL

static struct device *dev;
static u16_t rows;
static u8_t ppt;
static u8_t font_width;
static u8_t font_height;

#define SELECTED_FONT_INDEX  4  // perhaps make this a config parameter

/*---------------------------------------------------------------------------*/
/*                                                                           */
/*---------------------------------------------------------------------------*/
void display_play(void)
{
    u8_t x_offset = 0;
    u8_t y_offset;

    while (1) {

        for (int i=0; i < rows; i++) {

            y_offset = i * ppt;

            switch (i) {
                case 0:
                    cfb_print(dev, " average", x_offset, y_offset);
                    break;
                case 1:
                    cfb_print(dev, " good",    x_offset, y_offset);
                    break;
                case 2:
                    cfb_print(dev, " better",  x_offset, y_offset);
                    break;
                case 3:
                    cfb_print(dev, " best",    x_offset, y_offset);
                    break;
                default:
                    break;
            }

            cfb_framebuffer_finalize(dev);

            k_sleep(K_MSEC(300));
        }

        cfb_framebuffer_clear(dev, false);

        if (x_offset > 50)
            x_offset = 0;
        else
            x_offset += 5;
    }
}

/*---------------------------------------------------------------------------*/
/*                                                                           */
/*---------------------------------------------------------------------------*/
void display_init(void)
{
    dev = device_get_binding(DISPLAY_DRIVER);

    if (dev == NULL) {
        LOG_ERR("Device not found");
        return;
    }

    if (display_set_pixel_format(dev, PIXEL_FORMAT_MONO10) != 0) {
        LOG_ERR("Failed to set required pixel format");
        return;
    }

    LOG_INF("Binding to %s", DISPLAY_DRIVER);

    if (cfb_framebuffer_init(dev)) {
        LOG_ERR("Framebuffer initialization failed!");
        return;
    }

    cfb_framebuffer_clear(dev, true);

    display_blanking_off(dev);

    rows = cfb_get_display_parameter(dev, CFB_DISPLAY_ROWS);
    ppt  = cfb_get_display_parameter(dev, CFB_DISPLAY_PPT);

    int num_fonts = cfb_get_numof_fonts(dev);

    for (int idx = 0; idx < num_fonts; idx++) {

        cfb_get_font_size(dev, idx, &font_width, &font_height);

        LOG_INF("Index[%d] font dimensions %2dx%d",
                idx, font_width, font_height);
    }

    cfb_framebuffer_set_font(dev, SELECTED_FONT_INDEX);

    LOG_INF("Selected font: index[%d]", SELECTED_FONT_INDEX);

    cfb_framebuffer_invert(dev);  // white on black

    LOG_INF("x_res %d, y_res %d, ppt %d, rows %d, cols %d",
            cfb_get_display_parameter(dev, CFB_DISPLAY_WIDTH),
            cfb_get_display_parameter(dev, CFB_DISPLAY_HEIGH),
            ppt,
            rows,
            cfb_get_display_parameter(dev, CFB_DISPLAY_COLS));
}