NCS can‘t be opened, when it changes to VSC mode!

idata · ‎07-04-2018

Hi, everyone ! I want to use NCS on my Embedded device. I know my device is not in the officially supported list. But I need it can work on it. And the debug message seems to tell us it can do this, except one problem.

the debug message look likes below：

Device 0 Address: 1-ma2450 - VID/PID 03e7:2150
D : [       0] ncDeviceOpen:418  File path ./mvnc/MvNCAPI-ma2450.mvcmd
Starting wait for connect with 2000ms timeout
--------my debug message--------
devices = 3
device:1d6b:0001
device:03e7:2150
-----------------------------------------------
Found Address: 1-ma2450 - VID/PID 03e7:2150
Found EP 0x81 : max packet size is 512 bytes
Found EP 0x01 : max packet size is 512 bytes
Found and opened device
Performing bulk write of 1038676 bytes...
----------the Embedded device print-----
usb 1-1: USB disconnect, device number 114
----------------------------------------------------------------
Successfully sent 1038676 bytes of data in 256.261697 ms (3.865418 MB/s)
Boot successful, device address 1-ma2450
D : [      0] ncDeviceOpen:423                ncDeviceOpen() XLinkBootRemote returned success 0
------my debug message-------
devices = 2
device:1d6b:0001
device:1d6b:0002

devices = 2
device:1d6b:0001
device:1d6b:0002
...
...
...

in my opinion， there is two stages. At the first stage, NCS work as a normal USB device. and it's PID is 2150. In this stage every thing is ok. Then api send some message to NCS. This message changes NCS work on VSC mode(I don't know what is VSC mode. i quote it from source code ). This is the reason why we can see Embedded device print usb 1-1: USB disconnect, device number 114. After this, API can not find the device. But when I use the command lsusb on tty(or terminal, whatever), NCS can be found in list. And it's PID is f63b(that's right. It is should be f63b, after openning NCS in VSC mode). The function libusb_get_device_list() can not get NCS. It only gets two other devices. Can someone help me ? I will be very grateful!!!

idata · ‎07-05-2018

@Ryan It looks like the system is not seeing the device when it re-enumerates as a USB 3 device. Here is some information about the NCS device and how it works in regards to USB.

What kind of embedded device are you using? Can you check usr/local/lib/mvnc for a file named MvNCAPI.mvcmd? This is the firmware that the device downloads when it gets accessed.

idata · ‎07-06-2018

@Tome_at_Intel I am very happy to receive your reply in such a short time. Maybe we have solved this problem. But it still need to be confirmed. We solve it by adding libusb_init() function before libusb_get_device_list(). Thanks for your answer again. :)