usb backend does not discover nrf51822 mbed board

[clemtaylor]

I'm trying to use pyOCD with the nrf51822 mbed board. pyOCD detects the board when I plug it in, but it does not discover the endpoints ("ERROR:root:Endpoints not found"). I am using the default libusb backend and the issue seems to be that getAllConnectedInterface() is looking for both an ep_out and ep_in. However, lsusb shows that the nrf51822 mbed board only has an in endpoint for the MBED CMSIS-DAP HID Interface.

If I use the test case in the hidapi library it seems to discover the board just fine.
By default interface/init.py uses pyusb for non-Darwin posix os. So I built the cython-hidapi (from https://github.com/trezor/cython-hidapi.git) and ran the try.py with the vid/pid for the mbed board and it opens the device and reads back some data. But when I force the backend to 'hidapiusb' via PYOCD_USB_BACKEND, basic_test.py segfaults doing a hid_write() someplace in inside of chooseBoard().

Should the pyusb backend work with the nrf51822 mbed board? I'm using a new install of fedora 20 on a x86_64 box.

I was using the nordic branch of pyOCD, but pyOCD never gets far enough in the startup for the nordic changes to have any effect.

[ECNU3D]

Hi clemtaylor, I've just noticed this issue #33, maybe the support for nrf51822 haven't been merged.

[clemtaylor]

I was using the nordic branch of pyOCD, but pyOCD never gets far enough for the nordic patches to take effect. It is not getting past chooseBoard() which is just looking at pid/vid/endpoints.

[0xc0170]

@clemtaylor , did the new pull request (not merged, just pull it from their branch) solve your issue?

[clemtaylor]

Yes, the EP0 fix worked for me.

I'm still running into other unrelated pyOCD/nrf51822 issues, but I can connect, flash non-softdevice applications and do some basic debug. I need to file another bug on usability issues with pyOCD and the nrf51822.