python using pymetawear to stream accelerometer data

david506hk

Hi All,

I am running Ubuntu 16.04 on Mac Mini and try to use python script to stream accelerometer data to desktop.

I found that the streaming data would stop unexpectly after a few thousand data points.

How can I solve it? Thanks a lot.

My testing python code:

    from pymetawear.client import MetaWearClient

    c = MetaWearClient(METAWEAR_ID)

    

    # Set data rate to 200 Hz and measureing range to +/- 8g

    c.accelerometer.set_settings(data_rate=DATA_RATE, data_range=DATA_RANGE)

    

    def testing_fun(acc_data):

        print("Original Epoch time: [{0}] - X: {1}, Y: {2}, Z: {3}".format(acc_data[0], *acc_data[1]))

        pass

    c.accelerometer.notifications(testing_fun)

Eric

You need to use the high frequency stream for streaming at 200Hz.

david506hk

Update:

I have turn on the debug mode by setting: c = MetaWearClient(METAWEAR_ID, debug = True)

Below is the debugging message I got just before the streaming of accelerometer data stopped.

Hope it can help. Thanks.

2017-01-30 19:42:25,774 DEBUG Subscribing to Accelerometer changes. (Sig#: 140506298349296)

2017-01-30 19:42:25,774 DEBUG Write  0x001d: 03 04 01

2017-01-30 19:42:25,825 DEBUG Write  0x001d: 03 02 01 00

2017-01-30 19:42:25,876 DEBUG Write  0x001d: 03 01 01

Eric

Did you switch to using high frequency stream?

david506hk

Thanks for your help!

Could you please kindly tell me how to switch to high frequency stream?

Is turning on high frequency stream a function in Ubuntu? or Python? or pymetawear?

Thanks again.

Eric

The pymetawear is a community provided library, not an official MbientLab one.  You can checkout the accelerometer example code to see if that can answer your question, or if not, leave a question with the pymetawear author.

https://github.com/hbldh/pymetawear/blob/2f11bfce539cdb31623f36724d1debefa8d39e94/examples/accelerometer.py