首页 > 解决方案 > 使用 Beaglebone Black SPI 上的函数初始化 LCD eadip203-6

问题描述

我正在尝试使用 beaglebone black 上的 SPI 写下 LCD 屏幕 eadip203-6 的 LCD 初始化功能。我在尝试执行这些功能时遇到了一些问题,最初屏幕卡住了,然后如果我评论上述功能并看看会发生什么,光标仍然闪烁。我试图从数据表的第 29,30 和 33,34,35,36,37,38,39,40 页开始执行此操作。我还没有写完所有 16 个函数。但是写了一些开始的。现在,只要我从上面的代码中执行最后两个函数,屏幕就会变成空白。你能告诉我我哪里错了吗?你能告诉我关于 CGRAM、SEGRAM、DDRAM 和忙标志的信息吗?

#include <stdint.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/types.h>
#include <linux/spi/spidev.h>

#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
static void transfer(int fd, uint16_t* tx, uint8_t cs);
void init_display(int fd);
void clear_display_func(int fd);
void return_home_func(int fd);
void power_mode_func(int fd);
void entry_mode_set_func(int fd);
void display_on_off_func(int fd);
void extended_function_set_func(int fd);
void cursor_display_shift_bias_func(int fd);
static void pabort(const char *s)
{
    perror(s);
    abort();
}

static const char *device = "/dev/spidev2.1";
static uint8_t mode=3;
static uint8_t bits = 8;
static uint32_t speed = 40000;
static uint16_t delay;

void clear_display_func(int fd)
{
        int ret;
        uint16_t clear_display[]={0xF8,0x80,0x00};
        for(ret=0; ret<3; ret++)
        {
                transfer(fd,&clear_display[ret],0);
                usleep(2000);
        }
}

void return_home_func(int fd)
{
        int ret;
        uint16_t return_home[]={0xF8,0x40,0x00};
        for(ret=0; ret<3; ret++)
        {
                transfer(fd,&return_home[ret],0);
                usleep(2000);
        }
}

void power_mode_func(int fd)
{

        int ret;
        uint16_t power_mode[]={0xF8,0xC0,0x00};
        for(ret=0; ret<3; ret++)
        {
                transfer(fd,&power_mode[ret],0);
                usleep(2000);
        }
}
void entry_mode_set_func(int fd)
{
        int ret;
        uint16_t entry_mode_set[]={0xF8,0xE0,0x00,
                                   0xF8,0x60,0x00};
        for(ret=0; ret<6; ret++)
        {
                transfer(fd,&entry_mode_set[ret],0);
                usleep(2000);
        }
}
void display_on_off_func(int fd)
{
        int ret;
        uint16_t display_on_off[]={0xF8,0xF0,0x00};
        for(ret=0; ret<3; ret++)
        {
                transfer(fd,&display_on_off[ret],0);
                usleep(2000);
        }
}
void extended_function_set_func(int fd)
{
        int ret;
        uint16_t extended_function_set[]={0xF8,0xD0,0x00};
        for(ret=0; ret<3; ret++)
        {
                transfer(fd,&extended_function_set[ret],0);
                usleep(2000);
        }
}
void cursor_display_shift_bias_func(int fd)
{
        int ret;
        uint16_t cursor_display_shift_bias[]={0xF8,0x50,0x80};
        for(ret=0; ret<3; ret++)
        {
            transfer(fd,&cursor_display_shift_bias[ret],0);
            usleep(2000);
        }
}
static void transfer(int fd, uint16_t* tx, uint8_t cs){
int ret;
uint16_t rx[ARRAY_SIZE(tx)] = {0, };
struct spi_ioc_transfer tr = {
    .tx_buf = (unsigned long)tx,
    .rx_buf = 0,
    .len = 1,
    .delay_usecs = delay,
    .speed_hz = speed,
    .bits_per_word = bits,
    .cs_change=cs,
};
printf("%u", cs);

ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
if (ret < 1)
    pabort("can't send spi message");


    puts("");

}





static void print_usage(const char *prog)
{
    printf("Usage: %s [-DsbdlHOLC3]\n", prog);
    puts("  -D --device   device to use (default /dev/spidev1.1)\n"
         "  -s --speed    max speed (Hz)\n"
         "  -d --delay    delay (usec)\n"
         "  -b --bpw      bits per word \n"
         "  -l --loop     loopback\n"
         "  -H --cpha     clock phase\n"
         "  -O --cpol     clock polarity\n"
         "  -L --lsb      least significant bit first\n"
         "  -C --cs-high  chip select active high\n"
         "  -3 --3wire    SI/SO signals shared\n");
    exit(1);
}

static void parse_opts(int argc, char *argv[])
{
    while (1) {
        static const struct option lopts[] = {
            { "device",  1, 0, 'D' },
            { "speed",   1, 0, 's' },
            { "delay",   1, 0, 'd' },
            { "bpw",     1, 0, 'b' },
            { "loop",    0, 0, 'l' },
            { "cpha",    0, 0, 'H' },
            { "cpol",    0, 0, 'O' },
            { "lsb",     0, 0, 'L' },
            { "cs-high", 0, 0, 'C' },
            { "3wire",   0, 0, '3' },
            { "no-cs",   0, 0, 'N' },
            { "ready",   0, 0, 'R' },
            { NULL, 0, 0, 0 },
        };
        int c;

        c = getopt_long(argc, argv, "D:s:d:b:lHOLC3NR", lopts, 
NULL);

        if (c == -1)
            break;

        switch (c) {
        case 'D':
            device = optarg;
            break;
        case 's':
            speed = atoi(optarg);
            break;
        case 'd':
            delay = atoi(optarg);
            break;
        case 'b':
            bits = atoi(optarg);
            break;
        case 'l':
            mode |= SPI_LOOP;
            break;
        case 'H':
            mode |= SPI_CPHA;
            break;
        case 'O':
            mode |= SPI_CPOL;
            break;
        case 'L':
            mode |= SPI_LSB_FIRST;
            break;
        case 'C':
            mode |= SPI_CS_HIGH;
            break;
        case '3':
            mode |= SPI_3WIRE;
            break;
        case 'N':
            mode |= SPI_NO_CS;
            break;
        case 'R':
            mode |= SPI_READY;
            break;
        default:
            print_usage(argv[0]);
            break;
        }
    }
}

int main(int argc, char *argv[])
{
    int ret = 0;
    int fd;

    parse_opts(argc, argv);

    fd = open(device, O_RDWR);
    if (fd < 0)
        pabort("can't open device");

    /*
     * spi mode
     */
    ret = ioctl(fd, SPI_IOC_WR_MODE, &mode);
    if (ret == -1)
        pabort("can't set spi mode");

    ret = ioctl(fd, SPI_IOC_RD_MODE, &mode);
    if (ret == -1)
        pabort("can't get spi mode");

    /*
     * bits per word
     */
    ret = ioctl(fd, SPI_IOC_WR_BITS_PER_WORD, &bits);
    if (ret == -1)
        pabort("can't set bits per word");

    ret = ioctl(fd, SPI_IOC_RD_BITS_PER_WORD, &bits);
    if (ret == -1)
        pabort("can't get bits per word");

    /*
     * max speed hz
     */
    ret = ioctl(fd, SPI_IOC_WR_MAX_SPEED_HZ, &speed);
    if (ret == -1)
        pabort("can't set max speed hz");

    ret = ioctl(fd, SPI_IOC_RD_MAX_SPEED_HZ, &speed);
    if (ret == -1)
        pabort("can't get max speed hz");

    printf("spi mode: %d\n", mode);
    printf("bits per word: %d\n", bits);
    printf("max speed: %d Hz (%d KHz)\n", speed, speed/1000);

    init_display(fd);
       usleep(20000);
    clear_display_func(fd);
       usleep(20000);
    return_home_func(fd);
       usleep(20000);
    power_mode_func(fd);
       usleep(20000);
    entry_mode_set_func(fd);
       usleep(20000);
    display_on_off_func(fd);
       usleep(20000);
    extended_function_set(fd);
       usleep(20000);
    cursor_display_shift_bias_func(int fd);
       usleep(20000);
close(fd);

return ret;

}

标签: cbeagleboneblackspilcd

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