cannot find my WCH-Link

[wangwang105]

I saw the same problem（ #1121）

in use Ubuntu (Linux w-VirtualBox 5.19.0-46-generic #47~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Wed Jun 21 15:35:31 UTC 2 x86_64 x86_64 x86_64 GNU/Linux) When I run pyocd list, it just shows No available debug probes are connected.

i ran lsusb on my ubuntu,output: Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Bus 002 Device 003: ID 1a86:8012 QinHeng Electronics WCH-Link

Bus 002 Device 002: ID 80ee:0021 VirtualBox USB Tablet

Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

i ran lsusb -v on my ubuntu,output:

Bus 002 Device 003: ID 1a86:8012 QinHeng Electronics WCH-Link

Couldn't open device, some information will be missing

Device Descriptor:

bLength                18

bDescriptorType         1

bcdUSB               2.00

bDeviceClass          239 Miscellaneous Device

bDeviceSubClass         2 

bDeviceProtocol         1 Interface Association

bMaxPacketSize0        64

idVendor           0x1a86 QinHeng Electronics

idProduct          0x8012 

bcdDevice            2.09

iManufacturer           1 wch.cn

iProduct                2 WCH-Link

iSerial                 3 BC5DC2A77F04

bNumConfigurations      1

Configuration Descriptor:

bLength                 9

bDescriptorType         2

wTotalLength       0x0062

bNumInterfaces          3

bConfigurationValue     1

iConfiguration          0 

bmAttributes         0x80

  (Bus Powered)

MaxPower              500mA

Interface Descriptor:

  bLength                 9

  bDescriptorType         4

  bInterfaceNumber        0

  bAlternateSetting       0

  bNumEndpoints           2

  bInterfaceClass       255 Vendor Specific Class

  bInterfaceSubClass      0 

  bInterfaceProtocol      0 

  iInterface              4 

  Endpoint Descriptor:

    bLength                 7

    bDescriptorType         5

    bEndpointAddress     0x02  EP 2 OUT

    bmAttributes            2

      Transfer Type            Bulk

      Synch Type               None

      Usage Type               Data

    wMaxPacketSize     0x0040  1x 64 bytes

    bInterval               0

  Endpoint Descriptor:

    bLength                 7

    bDescriptorType         5

    bEndpointAddress     0x83  EP 3 IN

    bmAttributes            2

      Transfer Type            Bulk

      Synch Type               None

      Usage Type               Data

    wMaxPacketSize     0x0040  1x 64 bytes

    bInterval               0

Interface Association:

  bLength                 8

  bDescriptorType        11

  bFirstInterface         1

  bInterfaceCount         2

  bFunctionClass          2 Communications

  bFunctionSubClass       2 Abstract (modem)

  bFunctionProtocol       1 AT-commands (v.25ter)

  iFunction               4 

Interface Descriptor:

  bLength                 9

  bDescriptorType         4

  bInterfaceNumber        1

  bAlternateSetting       0

  bNumEndpoints           2

  bInterfaceClass        10 CDC Data

  bInterfaceSubClass      0 

  bInterfaceProtocol      0 

  iInterface              0 

  Endpoint Descriptor:

    bLength                 7

    bDescriptorType         5

    bEndpointAddress     0x03  EP 3 OUT

    bmAttributes            2

      Transfer Type            Bulk

      Synch Type               None

      Usage Type               Data

    wMaxPacketSize     0x0040  1x 64 bytes

    bInterval               0

  Endpoint Descriptor:

    bLength                 7

    bDescriptorType         5

    bEndpointAddress     0x81  EP 1 IN

    bmAttributes            2

      Transfer Type            Bulk

      Synch Type               None

      Usage Type               Data

    wMaxPacketSize     0x0040  1x 64 bytes

    bInterval               0

Interface Descriptor:

  bLength                 9

  bDescriptorType         4

  bInterfaceNumber        2

  bAlternateSetting       0

  bNumEndpoints           1

  bInterfaceClass         2 Communications

  bInterfaceSubClass      2 Abstract (modem)

  bInterfaceProtocol      1 AT-commands (v.25ter)

  iInterface              0 

  CDC Header:

    bcdCDC               1.10

  CDC Call Management:

    bmCapabilities       0x00

    bDataInterface          1

  CDC ACM:

    bmCapabilities       0x02

      line coding and serial state

  CDC Union:

    bMasterInterface        2

    bSlaveInterface         1 

  Endpoint Descriptor:

    bLength                 7

    bDescriptorType         5

    bEndpointAddress     0x84  EP 4 IN

    bmAttributes            3

      Transfer Type            Interrupt

      Synch Type               None

      Usage Type               Data

    wMaxPacketSize     0x0040  1x 64 bytes

    bInterval               1

I hope you can fix it~~

[flit]

Do you have udev configured correctly to allow access to the device? See https://pyocd.io/docs/faq.html#debug-probe-is-not-available Also make sure you are using the latest version of pyocd.

[wangwang105]

In the same environment as above i ran ‘pyocd --version‘ on my ubuntu,output: ‘0.35.1’

i ran 'cat /etc/udev/rules.d/'

output:

49-stlinkv1.rules 49-stlinkv2-1.rules 49-stlinkv2.rules 49-stlinkv3.rules 49-wch-link.rules 60-vboxadd.rules 70-snap.firefox.rules 70-snap.snapd-desktop-integration.rules 70-snap.snapd.rules 70-snap.snap-store.rules

---

There are rules, but there is still no way to recognize wch-link，hope you give me some suggestions~

[flit]

Even with the udev rule file in place, I still think there is some issue with permissions. That's because lsusb failed to open the device ("Couldn't open device, some information will be missing").

If you haven't restarted your system or udev since installing the rules, then that would explain this.

The rules in 49-wch-link.rules will create a wch-link* link under /dev somewhere (I'm not a Linux user, so I don't exactly where it would appear). You can also look for 0666 permissions on the WCH-Link device file.

Beyond that, I'm not sure what it could be… you might have to do some debugging. The amount that I can help is limited since I don't have a WCH-Link. I do know other people are using it though since someone contributed a patch for pyocd to be able to see a WCH-Link.

[gerryqd]

It works well on my PCs, both windows and Ubuntu. I suffered such kind of thing. But I think you can avoid the problem via below actions,

1. Upgrade the FW to latest one.
2. Avoid use of Virtualbox, use raw Linux directly.

[wangwang105]

It works well on my PCs, both windows and Ubuntu. I suffered such kind of thing. But I think you can avoid the problem via below actions,

1. Upgrade the FW to latest one.

2. Avoid use of Virtualbox, use raw Linux directly.

thanks for you advice. i will try what you suggested.