2020-12-18 04:28 PM
Hello! I am trying to access the Virtual COM Port of my 32F746GDISCOVERY' board. Unfortunately, the the COM port is not listed correctly in my system (Ubuntu 16.04). This is the output of "lsusb -v"
Bus 001 Device 012: ID 0483:3752 STMicroelectronics
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2 ?
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x0483 STMicroelectronics
idProduct 0x3752
bcdDevice 1.00
iManufacturer 1 STMicroelectronics
iProduct 2 STM32 STLink
iSerial 3 066CFF535651727067063241
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 105
bNumInterfaces 3
bConfigurationValue 1
iConfiguration 0
bmAttributes 0x80
(Bus Powered)
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 255 Vendor Specific Subclass
bInterfaceProtocol 255 Vendor Specific Protocol
iInterface 4 ST-Link Debug
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
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x01 EP 1 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 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0020 1x 32 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 6 ST-Link VCP Ctrl
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 2 Communications
bInterfaceSubClass 2 Abstract (modem)
bInterfaceProtocol 1 AT-commands (v.25ter)
iInterface 6 ST-Link VCP Ctrl
CDC Header:
bcdCDC 1.10
CDC Call Management:
bmCapabilities 0x00
bDataInterface 2
CDC ACM:
bmCapabilities 0x06
sends break
line coding and serial state
CDC Union:
bMasterInterface 1
bSlaveInterface 2
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x84 EP 4 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0008 1x 8 bytes
bInterval 255
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 10 CDC Data
bInterfaceSubClass 0 Unused
bInterfaceProtocol 0
iInterface 7 ST-Link VCP Data
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x05 EP 5 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 0x85 EP 5 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 0
Device Status: 0x0000
(Bus Powered)
which seem OK to me. However, "dmesg | grep tty" shows
[ 0.000000] console [tty0] enabled
[ 1.216778] tty ttyS8: hash matches
[ 5.016946] cdc_acm 1-1:1.2: ttyACM0: USB ACM device
[ 50.552564] cdc_acm 1-1:1.2: ttyACM0: USB ACM device
[ 117.338140] cdc_acm 1-1:1.2: ttyACM0: USB ACM device
[ 313.987037] cdc_acm 1-1:1.2: ttyACM0: USB ACM device
[ 1255.781209] cdc_acm 1-1:1.1: ttyACM0: USB ACM device
[ 1280.179821] cdc_acm 1-1:1.1: ttyACM0: USB ACM device
[ 1419.712027] cdc_acm 1-1:1.1: ttyACM0: USB ACM device
[ 1452.144266] cdc_acm 1-1:1.1: ttyACM0: USB ACM device
with no "ttyUSB*" entry. Any clue? :)
Solved! Go to Solution.
2020-12-19 03:20 AM
the descriptors are fine, I get the same. You should see ttyACM0 which you can use:
$ ls -l /dev/serial/by-id/usb-STMicroelectronics_STM32_STLink_*
lrwxrwxrwx 1 root root 13 Dec 19 12:09 /dev/serial/by-id/usb-STMicroelectronics_STM32_STLink_066DFF303739465043112657-if01 -> ../../ttyACM0
hth
KnarfB
2020-12-19 03:20 AM
the descriptors are fine, I get the same. You should see ttyACM0 which you can use:
$ ls -l /dev/serial/by-id/usb-STMicroelectronics_STM32_STLink_*
lrwxrwxrwx 1 root root 13 Dec 19 12:09 /dev/serial/by-id/usb-STMicroelectronics_STM32_STLink_066DFF303739465043112657-if01 -> ../../ttyACM0
hth
KnarfB
2020-12-28 08:42 AM
Thanks @KnarfB! I think I simply had an unrelated issue with the communication over UART.