Myo Connect unresponsive/crash after starting and shutting down hub multiple times about myo-python HOT 19 CLOSED

To me this sounds more like a bug in Myo Connect, but of course it could be possible that I did something wrong with the bindings. For now, maybe you can try to work around this problem and create only one single Hub object for your application. If you want to pause the Hub, it should be possible to run it again after it stopped (returning False from a Listener or calling Hub.stop()).

from myo-python.

Well, I tried the restarting some time ago (when it was still the bindings modified by Juharris), and I didn't get it to work successfully back then. Is there a specific restart method? Or do you just have to mess with the attributes/fields? Like Hub.running?

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Hi,
I have a problem with connecting. I dont see the myo.py module in this data
This is my first time with python so maybe it is an obvious mistake, and I would be very grateful if you could help me and explain how to connect to myo. Did I miss a step or something. I am in a good directory but it keeps saying that there is no module named myo. :/

from myo-python.

Hi Anelica,
If I had to guess, you probably missed the "pip install -e myo-python" step which adds the library to your Python path variable.

from myo-python.

I am doing it on mac OSX. Do I just type that in python console? Because it says invalid syntax

Very sorry to bother you with this stupid questions but I am just a beginner.

I have managed to install it but the same message shows again. Shouldnt there be a file named myp.py and that would be the modul I a m looking for? Or I am missing the point.

from myo-python.

I could be wrong, but you probably just need to add the myo sdk and the bindings to your path. There's some installation information on this Github:

$ git clone [email protected]:NiklasRosenstein/myo-python
$ virtualenv env --no-site-packages
$ source env/bin/activate
$ pip install -e myo-python
$ export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:$(pwd)/myo-sdk-mac-0.8.1/myo.framework
$ python3 myo-python/examples/hello_myo.py

I don't really now OSX, but I figure this should be done in your Mac Console, not in your Python IDE.
If you don't have pip (I don't know if all Python versions automatically include it), you should install it.
Maybe this can help for that: http://stackoverflow.com/questions/17271319/installing-pip-on-mac-os-x

from myo-python.

You helped me a lot! thank you!
I hade to update software to be able to install this so it took me whole day.
And now when I tought I have it, another problem occured. :(
Seems like something is wrong with hub

when i type hub=libmyo.Hub() i get this:

Traceback (most recent call last):
File "", line 1, in
File "/Users/ANELA/Documents/modules/myo-python-master/myo/init.py", line 74, in init
self._hub = _myo.Hub()
File "/Users/ANELA/Documents/modules/myo-python-master/myo/lowlevel/ctyping.py", line 250, in init
lib.init_hub(byref(self), byref(error))
File "/Users/ANELA/Documents/modules/myo-python-master/myo/lowlevel/ctyping.py", line 59, in getattr
raise AttributeError(name)
AttributeError: init_hub

Do you maybe know what is the problem?

from myo-python.

@anelica Have you called libmyo.init() before creating a Hub object?

from myo-python.

@NiklasRosenstein Yes! This is what I get

libmyo.init()
Traceback (most recent call last):
File "", line 1, in
File "/Users/ANELA/Documents/modules/myo-python-master/myo/lowlevel/ctyping.py", line 126, in init
self._lib = ctypes.cdll.LoadLibrary(lib_name)
File "/Users/ANELA/anaconda/lib/python2.7/ctypes/init.py", line 443, in LoadLibrary
return self._dlltype(name)
File "/Users/ANELA/anaconda/lib/python2.7/ctypes/init.py", line 365, in init
self._handle = _dlopen(self._name, mode)
OSError: dlopen(myo, 6): no suitable image found. Did find:
myo: not a file

from myo-python.

Apparently you haven't set up the environment variables correctly. Did you add to DYLD_LIBRARY_PATH the path to the myo.framework folder inside the Myo SDK you downloaded? Please check the instructions again. You might need to adjust the path when the Myo SDK is not in the same directory as your current working directory (the example uses $(pwd) to get the full path to the current working directory and reference the Myo SDK from there).

PS: Please create a new issue next time, you basically hijacked this thread ;-)

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@maartendruwe

Well, I tried the restarting some time ago (when it was still the bindings modified by Juharris), and I didn't get it to work successfully back then. Is there a specific restart method? Or do you just have to mess with the attributes/fields? Like Hub.running?

To be honest, I haven't really tried to restart the Hub yet. Hub.running should be a read-only field so that shouldn't be the solution. I'll have to investigate if a simple Hub.stop(True) and Hub.run(1000, listener) doesn't do it.

from myo-python.

@NiklasRosenstein well I think I have!
It is in my documents under folder modules where the sdk folder is so I typed this

export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:/Users/ANELA/Documents/modules/sdk/myo.framework 

Is that ok?

I am so sorry, it is my first time on GitHub :D

from myo-python.

@NiklasRosenstein Now i have put the sdk folder into the myo-python-master folder so that they are in the same and added the path but it is still not working.

Could you just tell me if i am doing good.
1.downloaded myo-python-master
2.installed via terminal with pip install
3.downloaded myo sdk
4.sdk folder is in myo-python-master folder
5.than I export it:
export DYLD_LIBRARY_PATH=$DYLD_LIBRARY_PATH:/Users/ANELA/Documents/modules/myo-python-master/sdk/myo.framework
or with the pwd
6.i launch spyder (python 2.7)
7. i type: import myo as libmyo
libmyo.init()

Is that it? Because I still get the same mistake over and over. I am sure that I am missing the obvious point here :S

from myo-python.

@anelica Looks OK to me right now. I'll check this out on my mac asap.

from myo-python.

@anelica Do you launch spyder from the terminal?

from myo-python.

@NiklasRosenstein no I launch it via launcher.app

from myo-python.

@anelica The DYLD_LIBRARY_PATH you set up won't be visible to Spyder then. It's only inherited by the processes you start from the terminal. Not sure if it will work if you start it with open -a Spyder.

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@maartendruwe Were you able to work around this for the moment? I didn't find the time to look into this yet, sorry.

from myo-python.

When I take the hello_myo.py example and change it to

    hub.set_locking_policy(libmyo.LockingPolicy.none)
    hub.run(1000, Listener())

    while True:
        time.sleep(1.0)
        hub.shutdown()
        print("\nRestarting hub...")
        hub.run(1000, Listener())

I get

Connecting to Myo ... Use CTRL^C to exit.
[0.9288330078125][-0.0797119140625][-0.14874267578125][-0.329833984375][<Pose: rest>][ ][ ][-54]54]
Restarting hub...
Traceback (most recent call last):
  File "myo-python\examples\hello_myo.py", line 161, in <module>
    main()
  File "myo-python\examples\hello_myo.py", line 144, in main
    hub.shutdown()
  File "c:\users\niklas\repos\niklasrosenstein\myo-python\myo-python\myo\__init__.py", line 283, in shutdown
    self._hub.shutdown()
  File "c:\users\niklas\repos\niklasrosenstein\myo-python\myo-python\myo\lowlevel\ctyping.py", line 328, in shutdown
    self._notnull()
  File "c:\users\niklas\repos\niklasrosenstein\myo-python\myo-python\myo\lowlevel\ctyping.py", line 168, in _notnull
    raise RuntimeError(message)
RuntimeError: Hub object is nullptr

But not the behaviour @maartendruwe described. Looking into myo.lowlevel.ctyping.Hub.shutdown(), we can find

    def shutdown(self):
        """
        Shuts the Hub down if it is running. The object is not usable
        after calling this function.
        """

        self._notnull()
        error = ErrorDetails()
        result = lib.shutdown_hub(self, byref(error))
        self.value = None
        error.raise_on_error()
        return result

If I remember correctly, it was documented in the Myo SDK that you can not re-use the hub once you shut it down (it's being deallocated). Creating a new lowlevel Hub object after the old has been shut down will fix this.

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