RPi + char lcd + uinput

vfo.c

#include <stdio.h>
#include <linux/input.h>
#include <linux/uinput.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <wiringPi.h>          
#include <lcd.h>               
 
//#define LCD_RS  6               //Register select pin
//#define LCD_E   5               //Enable Pin
#define LCD_RS  25               //Register select pin
#define LCD_E   24               //Enable Pin
#define LCD_D4  4               //Data pin 4
#define LCD_D5  0               //Data pin 5
#define LCD_D6  1               //Data pin 6
#define LCD_D7  3               //Data pin 7
 
void show_lcd(int lcd, char *freq_str, char *step_str)
{
    lcdPosition(lcd, 0, 0);
    lcdPuts(lcd, freq_str);
    lcdPosition(lcd, 0, 1);
    lcdPuts(lcd, step_str);
}

void show_term(char *str)
{
    printf("%s\r", str);
    fflush(stdout);
}

void freq_to_str(int freq, char *str)
{
    int mhz = freq / 1000000;
    int hz = freq % 1000000;
    sprintf(str, "%3d.%06d MHz", mhz, hz);
}

void step_to_str(int step, char *str)
{
    char tmp[32];
    if (step < 1000) {
        sprintf(tmp, "step: %dHz", step);
        sprintf(str, "%-16s", tmp);
    } else if (step < 1000000) {
        sprintf(tmp, "step: %dkHz", step / 1000);
        sprintf(str, "%-16s", tmp);
    } else {
        sprintf(tmp, "step: %dMHz", step / 1000000);
        sprintf(str, "%-16s", tmp);
    }
}

int main(int argc, char *argv[])
{
    int fd = open("/dev/input/event0", O_RDONLY);
    if (fd < 0) {
        fprintf(stderr, "Cannot open input\n");
        return 1;
    }

    wiringPiSetup();        
    int lcd = lcdInit(2, 16, 4, LCD_RS, LCD_E, LCD_D4, LCD_D5, LCD_D6, LCD_D7, 0, 0, 0, 0);

    int freq = 144000000;
    char freq_str[32];
    int step = 1;
    char step_str[32];

    while (1) {
        freq_to_str(freq, freq_str);
        step_to_str(step, step_str);
        show_term(freq_str);
        show_lcd(lcd, freq_str, step_str);
        struct input_event ev;
        int ret = read(fd, &ev, sizeof(ev));
        if (ret != sizeof(ev)) {
            fprintf(stderr, "unexpected read count\n");
            continue;
        }
        if (ev.code == 8 && ev.type == 2) {
            if (ev.value == 1) {
                freq += step;
            }
            if (ev.value == -1) {
                freq -= step;
            }
        } else if (ev.type == 1 && ev.value == 1) {
            if (ev.code == 0x110) {
                if (step * 10 <= 1000000) {
                    step *= 10;
                }
            }
            if (ev.code == 0x111) {
                if (step / 10 > 0) {
                    step /= 10;
                }
            }
        }
        //printf("type:%x value:%x code:%x\n", ev.type, ev.value, ev.code);
    }
    return 0;
}