rc_test_dsm.c

/**
 * @example    rc_test_dsm.c
 *
 * Prints out the normalized dsm2/dsmx values. Make sure the transmitter and
 * receiver are paired before testing. Use the rc_pair_dsm example if you didn't
 * already bind receiver to transmitter with a bind plug the old fashioned way.
 * The satellite receiver remembers which transmitter it is paired to, not your
 * BeagleBone.
 *
 * If the values you read are not normalized between +-1, then you should run
 * the rc_calibrate_dsm example to save your particular transmitter's min and
 * max channel values.
 */

#include <stdio.h>
#include <signal.h>
#include <getopt.h>
#include <rc/dsm.h>
#include <rc/time.h>

// possible printing modes, user selected with command line arguments
typedef enum p_mode_t{
        P_MODE_NONE,
        P_MODE_RAW,
        P_MODE_NORM
} p_mode_t;

static int running = 0;
static p_mode_t print_mode;

// printed if some invalid argument was given
static void __print_usage(void)
{
        printf("\n");
        printf("-r      print raw channel values in microseconds\n");
        printf("-n      print normalized channel values/s\n");
        printf("-h      print this help message\n");
        printf("\n");
}

// interrupt handler to catch ctrl-c
static void __signal_handler(__attribute__ ((unused)) int dummy)
{
        running=0;
        return;
}

static void __new_dsm_data_callback(void)
{
        int i;
        printf("\r");// keep printing on same line
        int channels = rc_dsm_channels();
        // print framerate
        printf("%d/", rc_dsm_resolution());
        // print num channels in use
        printf("%d-ch ", channels);
        // print all channels
        if(print_mode==P_MODE_NORM){
                for(i=0;i<channels;i++){
                        printf("%d:% 0.2f ", i+1, rc_dsm_ch_normalized(i+1));
                }
        }
        else{
                for(i=0;i<channels;i++){
                        printf("%d:% 4d ", i+1, rc_dsm_ch_raw(i+1));
                }
        }
        fflush(stdout);
}

int main(int argc, char *argv[])
{
        int c;
        print_mode = P_MODE_NONE;

        // parse arguments
        opterr = 0;
        while ((c = getopt(argc, argv, "rnh")) != -1){
                switch (c){
                case 'r':
                        if(print_mode!=P_MODE_NONE){
                                printf("\ntoo many arguments given\n");
                                __print_usage();
                                return -1;
                        }
                        print_mode = P_MODE_RAW;
                        break;
                case 'n':
                        if(print_mode!=P_MODE_NONE){
                                printf("\ntoo many arguments given\n");
                                __print_usage();
                                return -1;
                        }
                        print_mode = P_MODE_NORM;
                        break;
                        break;
                case 'h':
                        __print_usage();
                        return 0;
                default:
                        fprintf(stderr,"Invalid Argument\n");
                        __print_usage();
                        return -1;
                }
        }

        if(print_mode==P_MODE_NONE){
                fprintf(stderr, "Please select raw or normalized mode\n");
                __print_usage();
                return -1;
        }


        if(rc_dsm_init()) return -1;

        printf("\n");
        printf("Make sure transmitter and receiver are bound and on.\n");
        printf("If data is received, the normalized values will be printed\n");
        printf("here along with the bit resolution and the number of channels\n");
        printf("\n");
        printf("If connection is lost the number of seconds since last packet\n");
        printf("will be displayed\n");
        printf("\n");

        // set signal handler so the loop can exit cleanly
        signal(SIGINT, __signal_handler);
        running =1;

        printf("Waiting for first packet");
        fflush(stdout);
        while(rc_dsm_is_new_data()==0){
                if(running==0){
                        rc_dsm_cleanup();
                        return 0;
                }
                rc_usleep(50000);
        }

        // first packet arrived, set the callback and run
        rc_dsm_set_callback(__new_dsm_data_callback);

        // main loop monitor if connection is active or now
        while(running){
                if(rc_dsm_is_connection_active()==0){
                        printf("\rSeconds since last DSM packet: ");
                        printf("%0.1f ", rc_dsm_nanos_since_last_packet()/1000000000.0);
                        printf("                             ");
                        fflush(stdout);
                }
                rc_usleep(500000);
        }

        rc_dsm_cleanup();
        printf("\n");
        return 0;
}