MMR Failed to discover gatt characteristics (status = 3)

I recently purchased two MMRs and began working with these today after charging them.

One of these MMR refuses to connect in the python code example,** stream_acc.py.** My two older MMRs and the other new MMR has no issues. I use the older two MMRs for logging applications. The new ones are to be used for streaming applications.

The following is the error that I receive in the python code:

Traceback (most recent call last):
File "", line 11, in
File "C:\Users\mjupina\Documents\Vizard_user_files\MetaWear-SDK-Python-master\examples\stream_acc.py", line 48, in
device.connect()
File "C:\Program Files\WorldViz\Vizard6\bin\lib\site-packages\mbientlab\metawear\metawear.py", line 195, in connect
raise result[0]
mbientlab.warble.WarbleException: Failed to discover gatt characteristics (status = 3)

This MMR generating this error does connect to the MetaBase App and does stream acc data, so why the connectivity problem in python?

Thanks.

Comments

  • Does it work with the metabase app?

  • Yes, this MMR works with the metabase app, so what is the difference between the app connecting to this MMR and the stream_acc.py code making the connection to this MMR. My other three MMRs work reliably with the code.

  • Maybe you have the MAC address wrong? try just the python scanning example to see if your python based machine detects the sensor and confirm the MAC address.

  • I will try the python scanning example as suggested when I get a chance, but the MAC address on the plastic package matches the MAC address shown in the MetaBase App so I believe that the MAC address is correct.

  • edited April 2020

    That's good. That eliminates some possible issues.
    Now focus on the python platform by testing other Python scripts and the python scanning example: https://github.com/mbientlab/MetaWear-SDK-Python/blob/master/examples/scan_connect.py

    Also you can try if just the standard btmon or bt tools on your computer to scan for the device:

  • The python scanning example did work. I tried the LED example and it turned the LED on but it didn't always turn it off so I had to use the MetaBase app to reset it to get the LED to turn off. The streaming example is now working. Since it is a new device, if I continue to see any intermittent performance with the Bluetooth then I will file a ticket to request a replacement. Since I have other MMRs, I have benchmarks to compare with this device.

  • Sounds good.

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