MyoSDK并编译其示例错误

Question

I am new to C++ and this is my first real attempt to create anything (although I haven't really started yet...) I'm trying to compile the samples code from the MyoSDK (awesome device by the way) which can be found here. Every time I compile, I get an error. My question essential comes down to why is it looking at __imp_libmyo_*** instead of just libmyo ?

F:\GitHub\Myo\MyoSDK\samples>g++ -g hello-myo.cpp -o hello-myo -I F:/Github/Myo/ MyoSDK/include F:\Users\JACOB'~1\AppData\Local\Temp\cc5AVo40.o: In function `myo::ThrowOnError::~ThrowOnError()':
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/../impl/../detail/ThrowOnError.hpp:33:undefined reference to `__imp_libmyo_error_kind'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/../impl/../detail/ThrowOnError.hpp:37:undefined reference to `__imp_libmyo_error_cstring'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/../impl/../detail/ThrowOnError.hpp:38:undefined reference to `__imp_libmyo_free_error_details'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/../impl/../detail/ThrowOnError.hpp:43:undefined reference to `__imp_libmyo_error_cstring'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/../impl/../detail/ThrowOnError.hpp:44:undefined reference to `__imp_libmyo_free_error_details'
F:\Users\JACOB'~1\AppData\Local\Temp\cc5AVo40.o: In function `myo::Myo::vibrate(myo::Myo::VibrationType)':
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/../impl/Myo_impl.hpp:13:undefined ref erence to `__imp_libmyo_vibrate'
F:\Users\JACOB'~1\AppData\Local\Temp\cc5AVo40.o: In function `myo::Hub::Hub(std::basic_string<char,std::char_traits<char>,std::allocator<char> > const&)':
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:23:undefined reference t o `__imp_libmyo_init_hub'
F:\Users\JACOB'~1\AppData\Local\Temp\cc5AVo40.o: In function `myo::Hub::~Hub()':F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:32:undefined reference t o `__imp_libmyo_shutdown_hub'
F:\Users\JACOB'~1\AppData\Local\Temp\cc5AVo40.o: In function `myo::Hub::waitForMyo(unsigned int)::local::handler(void*,void const*)':
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:44:undefined reference t o `__imp_libmyo_event_get_myo'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:46:undefined reference t o `__imp_libmyo_event_get_type'
F:\Users\JACOB'~1\AppData\Local\Temp\cc5AVo40.o: In function `myo::Hub::waitForMyo(unsigned int)':
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:59:undefined reference t o `__imp_libmyo_run'
F:\Users\JACOB'~1\AppData\Local\Temp\cc5AVo40.o: In function `myo::Hub::onDeviceEvent(void const*)':
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:94:undefined reference t o `__imp_libmyo_event_get_myo'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:98:undefined reference t o `__imp_libmyo_event_get_type'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:112:undefined reference to `__imp_libmyo_event_get_timestamp'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:114:undefined reference to `__imp_libmyo_event_get_type'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:116:undefined reference to `__imp_libmyo_event_get_firmware_version'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:117:undefined reference to `__imp_libmyo_event_get_firmware_version'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:118:undefined reference to `__imp_libmyo_event_get_firmware_version'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:119:undefined reference to `__imp_libmyo_event_get_firmware_version'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:127:undefined reference to `__imp_libmyo_event_get_firmware_version'
F:\Users\JACOB'~1\AppData\Local\Temp\cc5AVo40.o:F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:128:more undefined references to `__imp_libmyo_event_get _firmware_version' follow
F:\Users\JACOB'~1\AppData\Local\Temp\cc5AVo40.o: In function `myo::Hub::onDeviceEvent(void const*)':
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:140:undefined reference to `__imp_libmyo_event_get_x_direction'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:139:undefined reference to `__imp_libmyo_event_get_arm'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:150:undefined reference to `__imp_libmyo_event_get_orientation'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:150:undefined reference to `__imp_libmyo_event_get_orientation'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:150:undefined reference to `__imp_libmyo_event_get_orientation'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:150:undefined reference to `__imp_libmyo_event_get_orientation'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:154:undefined reference to `__imp_libmyo_event_get_accelerometer'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:154:undefined reference to `__imp_libmyo_event_get_accelerometer'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:154:undefined reference to `__imp_libmyo_event_get_accelerometer'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:159:undefined reference to `__imp_libmyo_event_get_gyroscope'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:159:undefined reference to `__imp_libmyo_event_get_gyroscope'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:159:undefined reference to `__imp_libmyo_event_get_gyroscope'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:163:undefined reference to `__imp_libmyo_event_get_pose'
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:166:undefined reference to `__imp_libmyo_event_get_rssi'
F:\Users\JACOB'~1\AppData\Local\Temp\cc5AVo40.o: In function `myo::Hub::run(unsigned int)':
F:/Github/Myo/MyoSDK/include/myo/cxx/impl/Hub_impl.hpp:184:undefined reference to `__imp_libmyo_run'
collect2.exe:error:ld returned 1 exit status

The files being compiled are all in the SDK. If you download it and compile it like I did, you should get this error.

To show the first error, I will include the ThrowOnError.hpp and libmyo.h

// Copyright (C) 2013-2014 Thalmic Labs Inc.
// Distributed under the Myo SDK license agreement. See LICENSE.txt for details.
#ifndef MYO_CXX_DETAIL_THROWONERROR_HPP
#define MYO_CXX_DETAIL_THROWONERROR_HPP

#include <stdexcept>

#include <myo/libmyo.h>

#if defined(_MSC_VER) && _MSC_VER <= 1800
#define LIBMYO_NOEXCEPT(b)
#else
#if __cplusplus >= 201103L
# define LIBMYO_NOEXCEPT(b) noexcept(b)
#else
# define LIBMYO_NOEXCEPT(b)
#endif
#endif

namespace myo {

class ThrowOnError {
public:
    ThrowOnError()
    : _error()
    {
    }

    ~ThrowOnError() LIBMYO_NOEXCEPT(false)
    {
        if (_error)
        {
            switch (libmyo_error_kind(_error)) {
            case libmyo_error:
            case libmyo_error_runtime:
            {
                std::runtime_error exception(libmyo_error_cstring(_error));
                libmyo_free_error_details(_error);
                throw exception;
            }
            case libmyo_error_invalid_argument:
            {
                std::invalid_argument exception(libmyo_error_cstring(_error));
                libmyo_free_error_details(_error);
                throw exception;
            }
            case libmyo_success:
            {
                break;
            }
            }
        }
    }

    operator libmyo_error_details_t*()
    {
        return &_error;
    }

private:
    libmyo_error_details_t _error;

    // Not implemented
    ThrowOnError(const ThrowOnError&); // = delete;
    ThrowOnError& operator=(const ThrowOnError&); // = delete;
};

} //namespace libmyo

#endif // MYO_CXX_DETAIL_THROWONERROR_HPP

And the libmyo.h :

// Copyright (C) 2013-2014 Thalmic Labs Inc.
// Distributed under the Myo SDK license agreement. See LICENSE.txt for details.
#ifndef MYO_LIBMYO_H
#define MYO_LIBMYO_H

#include <stdint.h>

#include "libmyo/detail/visibility.h"

#ifdef __cplusplus
extern "C" {
#endif

/// @file libmyo.h
/// libmyo C API declarations.

typedef void* libmyo_hub_t;

/// \defgroup errors Error Handling
/// @{

/// Function result codes.
/// All libmyo functions that can fail return a value of this type.
typedef enum {
    libmyo_success,
    libmyo_error,
    libmyo_error_invalid_argument,
    libmyo_error_runtime
} libmyo_result_t;

/// Opaque handle to detailed error information.
typedef void* libmyo_error_details_t;

/// Return a null-terminated string with a detailed error message.
LIBMYO_EXPORT
const char* libmyo_error_cstring(libmyo_error_details_t);

/// Returns the kind of error that occurred.
LIBMYO_EXPORT
libmyo_result_t libmyo_error_kind(libmyo_error_details_t);

/// Free the resources allocated by an error object.
LIBMYO_EXPORT
void libmyo_free_error_details(libmyo_error_details_t);

/// @}

/// @defgroup libmyo_hub Hub instance
/// @{

/// Initialize a connection to the hub.
/// \a application_identifier must follow a reverse domain name format (ex. com.domainname.appname). Application
/// identifiers can be formed from the set of alphanumeric ASCII characters (a-z, A-Z, 0-9). The hyphen (-) and
/// underscore (_) characters are permitted if they are not adjacent to a period (.) character (i.e. not at the start or
/// end of each segment), but are not permitted in the top-level domain. Application identifiers must have three or more
/// segments. For example, if a company's domain is example.com and the application is named hello-world, one could use
/// "com.example.hello-world" as a valid application identifier. \a application_identifier can be NULL or empty.
/// @returns libmyo_success if the connection is successfully established, otherwise:
///  - libmyo_error_runtime if a connection could not be established
///  - libmyo_error_invalid_argument if \a out_hub is NULL
///  - libmyo_error_invalid_argument if \a application_identifier is longer than 255 characters
///  - libmyo_error_invalid_argument if \a application_identifier is not in the proper reverse domain name format
LIBMYO_EXPORT
libmyo_result_t libmyo_init_hub(libmyo_hub_t* out_hub, const char* application_identifier,
                                libmyo_error_details_t* out_error);

/// Free the resources allocated to a hub.
/// @returns libmyo_success if shutdown is successful, otherwise:
///  - libmyo_error_invalid_argument if \a hub is NULL
///  - libmyo_error if \a hub is not a valid \a hub
LIBMYO_EXPORT
libmyo_result_t libmyo_shutdown_hub(libmyo_hub_t hub, libmyo_error_details_t* out_error);

/// @}

/// @defgroup libmyo_myo Myo instances
/// @{

/// Opaque type corresponding to a known Myo device.
typedef void* libmyo_myo_t;

/// Types of vibration
typedef enum {
    libmyo_vibration_short,
    libmyo_vibration_medium,
    libmyo_vibration_long
} libmyo_vibration_type_t;

/// Vibrate the given myo.
/// Can be called when a Myo is paired.
/// @returns libmyo_success if the Myo successfully vibrated, otherwise
///  - libmyo_error_invalid_argument if \a myo is NULL
LIBMYO_EXPORT
libmyo_result_t libmyo_vibrate(libmyo_myo_t myo, libmyo_vibration_type_t type, libmyo_error_details_t* out_error);

/// Request the RSSI for a given myo.
/// Can be called when a Myo is paired. A libmyo_event_rssi event will likely be generated with the value of the RSSI.
/// @returns libmyo_success if the Myo successfully got the RSSI, otherwise
///  - libmyo_error_invalid_argument if \a myo is NULL
LIBMYO_EXPORT
libmyo_result_t libmyo_request_rssi(libmyo_myo_t myo, libmyo_error_details_t* out_error);

/// @}

/// @defgroup libmyo_poses Pose recognition.
/// @{

/// Supported poses.
typedef enum {
    libmyo_pose_rest           = 0, ///< Rest pose.
    libmyo_pose_fist           = 1, ///< User is making a fist.
    libmyo_pose_wave_in        = 2, ///< User has an open palm rotated towards the posterior of their wrist.
    libmyo_pose_wave_out       = 3, ///< User has an open palm rotated towards the anterior of their wrist.
    libmyo_pose_fingers_spread = 4, ///< User has an open palm with their fingers spread away from each other.
    libmyo_pose_reserved1      = 5, ///< Reserved value; not a valid pose.
    libmyo_pose_thumb_to_pinky = 6, ///< User is touching the tip of their thumb to the tip of their pinky.

    libmyo_num_poses,               ///< Number of poses supported; not a valid pose.

    libmyo_pose_unknown = 0xffff    ///< Unknown pose.
} libmyo_pose_t;

static const libmyo_pose_t libmyo_trained_poses[] = { libmyo_pose_rest, libmyo_pose_fist, libmyo_pose_wave_in,
                                                      libmyo_pose_wave_out, libmyo_pose_fingers_spread,
                                                      libmyo_pose_thumb_to_pinky };
static const unsigned int libmyo_num_trained_poses = sizeof(libmyo_trained_poses) / sizeof(libmyo_trained_poses[0]);

/// @}

/// @defgroup libmyo_events Event Handling
/// @{

/// Types of events.
typedef enum {
    libmyo_event_paired, ///< Successfully paired with a Myo.
    libmyo_event_unpaired, ///< Successfully unpaired from a Myo.
    libmyo_event_connected, ///< A Myo has successfully connected.
    libmyo_event_disconnected, ///< A Myo has been disconnected.
    libmyo_event_arm_recognized, ///< A Myo has recognized that it is now on an arm.
    libmyo_event_arm_lost, ///< A Myo has been moved or removed from the arm.
    libmyo_event_orientation, ///< Orientation data has been received.
    libmyo_event_pose, ///< A change in pose has been detected. @see libmyo_pose_t.
    libmyo_event_rssi, ///< An RSSI value has been received.
} libmyo_event_type_t;

/// Information about an event.
typedef const void* libmyo_event_t;

/// Retrieve the type of an event.
LIBMYO_EXPORT
uint32_t libmyo_event_get_type(libmyo_event_t event);

/// Retrieve the timestamp of an event.
/// @see libmyo_now() for details on timestamps.
LIBMYO_EXPORT
uint64_t libmyo_event_get_timestamp(libmyo_event_t event);

/// Retrieve the Myo associated with an event.
LIBMYO_EXPORT
libmyo_myo_t libmyo_event_get_myo(libmyo_event_t event);

/// Components of version.
typedef enum {
    libmyo_version_major,        ///< Major version.
    libmyo_version_minor,        ///< Minor version.
    libmyo_version_patch,        ///< Patch version.
    libmyo_version_hardware_rev, ///< Hardware revision.
} libmyo_version_component_t;

/// Hardware revisions.
typedef enum {
    libmyo_hardware_rev_c = 1, ///< Alpha units
    libmyo_hardware_rev_d = 2, ///< Consumer units
} libmyo_hardware_rev_t;

/// Retrieve the Myo armband's firmware version from this event.
/// Valid for libmyo_event_paired and libmyo_event_connected events.
LIBMYO_EXPORT
unsigned int libmyo_event_get_firmware_version(libmyo_event_t event, libmyo_version_component_t);

/// Enumeration identifying a right arm or left arm. @see libmyo_event_get_arm().
typedef enum {
    libmyo_arm_right, ///< Myo is on the right arm.
    libmyo_arm_left, ///< Myo is on the left arm.
    libmyo_arm_unknown, ///< Unknown arm.
} libmyo_arm_t;

/// Retrieve the arm associated with an event.
/// Valid for libmyo_event_arm_recognized events only.
LIBMYO_EXPORT
libmyo_arm_t libmyo_event_get_arm(libmyo_event_t event);

/// Possible directions for Myo's +x axis relative to a user's arm.
typedef enum {
    libmyo_x_direction_toward_wrist, ///< Myo's +x axis is pointing toward the user's wrist.
    libmyo_x_direction_toward_elbow, ///< Myo's +x axis is pointing toward the user's elbow.
    libmyo_x_direction_unknown, ///< Unknown +x axis direction.
} libmyo_x_direction_t;

/// Retrieve the x-direction associated with an event.
/// The x-direction specifies which way Myo's +x axis is pointing relative to the user's arm.
/// Valid for libmyo_event_arm_recognized events only.
LIBMYO_EXPORT
libmyo_x_direction_t libmyo_event_get_x_direction(libmyo_event_t event);

/// Index into orientation data, which is provided as a quaternion.
/// Orientation data is returned as a unit quaternion of floats, represented as `w + x * i + y * j + z * k`.
typedef enum {
    libmyo_orientation_x = 0, ///< First component of the quaternion's vector part
    libmyo_orientation_y = 1, ///< Second component of the quaternion's vector part
    libmyo_orientation_z = 2, ///< Third component of the quaternion's vector part
    libmyo_orientation_w = 3, ///< Scalar component of the quaternion.
} libmyo_orientation_index;

/// Retrieve orientation data associated with an event.
/// Valid for libmyo_event_orientation events only.
/// @see libmyo_orientation_index
LIBMYO_EXPORT
float libmyo_event_get_orientation(libmyo_event_t event, libmyo_orientation_index index);

/// Retrieve raw accelerometer data associated with an event in units of g.
/// Valid for libmyo_event_orientation events only.
/// Requires `index < 3`.
LIBMYO_EXPORT
float libmyo_event_get_accelerometer(libmyo_event_t event, unsigned int index);

/// Retrieve raw gyroscope data associated with an event in units of deg/s.
/// Valid for libmyo_event_orientation events only.
/// Requires `index < 3`.
LIBMYO_EXPORT
float libmyo_event_get_gyroscope(libmyo_event_t event, unsigned int index);

/// Retrieve the pose associated with an event.
/// Valid for libmyo_event_pose events only.
LIBMYO_EXPORT
libmyo_pose_t libmyo_event_get_pose(libmyo_event_t event);

/// Retreive the RSSI associated with an event.
/// Valid for libmyo_event_rssi events only.
LIBMYO_EXPORT
int8_t libmyo_event_get_rssi(libmyo_event_t event);

/// Return type for event handlers.
typedef enum {
    libmyo_handler_continue, ///< Continue processing events
    libmyo_handler_stop,     ///< Stop processing events
} libmyo_handler_result_t;

/// Callback function type to handle events as they occur from libmyo_run().
typedef libmyo_handler_result_t (*libmyo_handler_t)(void* user_data, libmyo_event_t event);

/// Process events and call the provided callback as they occur.
/// Runs for up to approximately \a duration_ms milliseconds or until a called handler returns libmyo_handler_stop.
/// @returns libmyo_success after a successful run, otherwise
///  - libmyo_error_invalid_argument if \a hub is NULL
///  - libmyo_error_invalid_argument if \a handler is NULL
LIBMYO_EXPORT
libmyo_result_t libmyo_run(libmyo_hub_t hub, unsigned int duration_ms, libmyo_handler_t handler, void* user_data,
                           libmyo_error_details_t* out_error);

/// @}

#ifdef __cplusplus
} // extern "C"
#endif

#endif // MYO_LIBMYO_H

Can anyone help me with my error? Where did I go wrong?

Answer 1

I just recently started working with the MYO as well, and I would like to mention that I started out trying to get it to compile in Cygwin, which was a very bad idea. There are too many things not included in the installer that cause it to fail, not to mention the settings on the MYO are for visual studio. If you have the ability to do it, I would recommend installing visual studio and running everything from there. I got a lot of errors before I tried this, and afterwards it was working perfectly for me. Also sorry for the answer 3 months after you posted, but I just started researching a similar issue recently.