c - PX4自动驾驶仪: "initialization makes integer from pointer without a cast"

Question

我目前已经开始开发 PX4 自动驾驶仪，并且正在研究示例应用程序之一，并尝试编译固件并将其上传到 Pixhawk。

问题是它无法加载，给我这些错误:

make[2]: * [px4_simple_app.c.o] Error 1 make[1]: * [/c/px4/Firmware/Build/px4fmu-v2_default.build//c/px4/Firmware/src/examples/px4_simple_app/module.pre.o] Error 2 make[1]: Leaving directory `/c/px4/Firmware/Build/px4fmu-v2_default.build' make: *** [/c/px4/Firmware/Build/px4fmu-v2_default.build/firmware.px4] Error 2

我不确定这些是什么意思，但检查代码在某一行中给了我这个错误:

初始化从指针生成整数，无需强制转换

从这一行开始:

int att_pub_fd = orb_advertise(ORB_ID(vehicle_attitude), &att);

我不知道如何解决这个问题。有人可以给我一些帮助吗？

这是代码的其余部分:

/**
 * @file px4_simple_app.c
 * Minimal application example for PX4 autopilot
 */

#include <string.h>
#include <nuttx/config.h>
#include <unistd.h>
#include <stdio.h>
#include <poll.h>

#include <uORB/uORB.h>
#include <uORB/topics/sensor_combined.h>
#include <uORB/topics/vehicle_attitude.h>

__EXPORT int px4_simple_app_main(int argc, char *argv[]);

int px4_simple_app_main(int argc, char *argv[])
{
printf("Hello Sky!\n");

/* subscribe to sensor_combined topic */
int sensor_sub_fd = orb_subscribe(ORB_ID(sensor_combined));
orb_set_interval(sensor_sub_fd, 1000);

/* advertise attitude topic */
struct vehicle_attitude_s att;
memset(&att, 0, sizeof(att));
int att_pub_fd = orb_advertise(ORB_ID(vehicle_attitude), &att);

/* one could wait for multiple topics with this technique, just using one here */
struct pollfd fds[] = {
    { .fd = sensor_sub_fd,   .events = POLLIN },
    /* there could be more file descriptors here, in the form like:
     * { .fd = other_sub_fd,   .events = POLLIN },
     */
};

int error_counter = 0;

while (true) {
    /* wait for sensor update of 1 file descriptor for 1000 ms (1 second) */
    int poll_ret = poll(fds, 1, 1000);

    /* handle the poll result */
    if (poll_ret == 0) {
        /* this means none of our providers is giving us data */
        printf("[px4_simple_app] Got no data within a second\n");
    } else if (poll_ret < 0) {
        /* this is seriously bad - should be an emergency */
        if (error_counter < 10 || error_counter % 50 == 0) {
            /* use a counter to prevent flooding (and slowing us down) */
            printf("[px4_simple_app] ERROR return value from poll(): %d\n"
                , poll_ret);
        }
        error_counter++;
    } else {

        if (fds[0].revents & POLLIN) {
            /* obtained data for the first file descriptor */
            struct sensor_combined_s raw;
            /* copy sensors raw data into local buffer */
            orb_copy(ORB_ID(sensor_combined), sensor_sub_fd, &raw);
            printf("[px4_simple_app] Accelerometer:\t%8.4f\t%8.4f\t%8.4f\n",
                (double)raw.accelerometer_m_s2[0],
                (double)raw.accelerometer_m_s2[1],
                (double)raw.accelerometer_m_s2[2]);

            /* set att and publish this information for other apps */
            att.roll = raw.accelerometer_m_s2[0];
            att.pitch = raw.accelerometer_m_s2[1];
            att.yaw = raw.accelerometer_m_s2[2];
            orb_publish(ORB_ID(vehicle_attitude), att_pub_fd, &att);
        }
        /* there could be more file descriptors here, in the form like:
         * if (fds[1..n].revents & POLLIN) {}
         */
    }
}

return 0;
}

Answer 1

函数

orb_advertise(ORB_ID(vehicle_attitude), &att) 

返回一个指针，并且您将其分配给一个 int。 我不确定你想做什么，但如果它指向一个整数，那么你需要取消引用指针。