<![CDATA[CoreS3 read data via usb_uart]]>Hello. I’m trying to read data via usb_uart on an M5Stack CoreS3 from a CDC-ACM device, without success.
Here some config entries.
I moved the logger to a different interface. I have no idea whether this is necessary, but this way it definitely doesn’t occupy the USB interface.

logger:
  baud_rate: 0
  hardware_uart: UART0
  level: VERBOSE
  initial_level: DEBUG
  logs: 
    usb_uart: VERBOSE
    usb_host: VERBOSE
    uart_debug: VERBOSE

Outputs

output:
  - platform: axp2101
    type: range
    channel: DLDO1
    id: lcd_backlight_output
    min_voltage: 2600
    max_voltage: 3300

  - platform: axp2101
    channel: ALDO1
    voltage: 1800

  - platform: axp2101
    channel: ALDO2
    voltage: 3300
  
  - platform: axp2101
    channel: BLDO1
    voltage: 2800
  
  - platform: axp2101
    channel: BLDO2
    voltage: 1500

Then I set these switches:

switch:
  - platform: gpio
    name: "bus_out_en_sw"
    internal: true
    pin:
      aw9523b: aw9523b_hub
      number: 1
    restore_mode: ALWAYS_ON

  - platform: gpio
    name: "usb_otg_en_sw"
    internal: true
    pin:
      aw9523b: aw9523b_hub
      number: 5
    restore_mode: ALWAYS_ON

  - platform: gpio
    name: "boost_en_sw"
    internal: true
    pin:
      aw9523b: aw9523b_hub
      number: 15
    restore_mode: ALWAYS_ON

  - platform: gpio
    name: "AW RST P0_2"
    internal: true
    pin:
      aw9523b: aw9523b_hub
      number: 2
    restore_mode: ALWAYS_ON

And configure the usb_uart

usb_uart:  
  - type: cdc_acm
    id: scanner_bus
    vid: 0x152A
    pid: 0x880F
    channels:
      - id: uch_1
        debug: true

The device is a barcode scanner Digitus DA-8002
DC 3.3 - 5V, 120 mA, idle 1uA
The scanner is set as "USB serial interface output".
Adapter USB-C to USB-A Greencell 2.4A 480 Mbps
Power supply CoreS3: Yingjiao YS35V-1203000, 12V, 3A, 36W
Baudrate scanner: 9600
The scanner is powered. When I plug it in, it beeps, and it also beeps when I scan.
It has a USB-A interface, and I’m using a USB-C to USB-A OTG adapter.
The scanner works without any problem with this exact adapter on a Windows PC and on an Android smartphone.
This is the log when I plug in the scanner.

[18:14:15.614][D][usb_host:265]: Open device 1
[18:14:15.615][D][usb_host:272]: Get descriptor device 1
[18:14:15.615][D][usb_host:279]: Device descriptor: vid 152A pid 880F
[18:14:15.616][D][usb_host:289]: Device connected: Manuf: MINJCODE; Prod: MINJCODE MJ2818A; Serial: 00000000050C
[18:14:15.618][V][usb_host:089]: *** Device descriptor ***
[18:14:15.618]bLength 18
[18:14:15.618]bDescriptorType 1
[18:14:15.618]bcdUSB 1.10
[18:14:15.618]bDeviceClass 0x2
[18:14:15.618]bDeviceSubClass 0x0
[18:14:15.618]bDeviceProtocol 0x0
[18:14:15.618]bMaxPacketSize0 64
[18:14:15.618]idVendor 0x152a
[18:14:15.618]idProduct 0x880f
[18:14:15.618]bcdDevice 1.00
[18:14:15.618]iManufacturer 1
[18:14:15.618]iProduct 2
[18:14:15.618]iSerialNumber 3
[18:14:15.618]bNumConfigurations 1
[18:14:15.627][V][usb_host:070]: *** Configuration descriptor ***
[18:14:15.627]bLength 9
[18:14:15.627]bDescriptorType 2
[18:14:15.627]wTotalLength 67
[18:14:15.627]bNumInterfaces 2
[18:14:15.627]bConfigurationValue 1
[18:14:15.627]iConfiguration 0
[18:14:15.627]bmAttributes 0x80
[18:14:15.627]bMaxPower 500mA
[18:14:15.652][V][usb_host:056]: 	*** Interface descriptor ***
[18:14:15.652][V][usb_host:056]: 	bLength 9
[18:14:15.652][V][usb_host:056]: 	bDescriptorType 4
[18:14:15.652][V][usb_host:056]: 	bInterfaceNumber 0
[18:14:15.652][V][usb_host:056]: 	bAlternateSetting 0
[18:14:15.652][V][usb_host:056]: 	bNumEndpoints 1
[18:14:15.652][V][usb_host:056]: 	bInterfaceClass 0x2
[18:14:15.652][V][usb_host:056]: 	iInterface 0
[18:14:15.669][V][usb_host:042]: 		*** Endpoint descriptor ***
[18:14:15.669][V][usb_host:042]: 		bLength 7
[18:14:15.669][V][usb_host:042]: 		bDescriptorType 5
[18:14:15.669][V][usb_host:042]: 		bEndpointAddress 0x82	EP 2 IN
[18:14:15.669][V][usb_host:042]: 		bmAttributes 0x3	INT
[18:14:15.669][V][usb_host:042]: 		wMaxPacketSize 8
[18:14:15.669][V][usb_host:042]: 		bInterval 10
[18:14:15.679][V][usb_host:056]: 	*** Interface descriptor ***
[18:14:15.679][V][usb_host:056]: 	bLength 9
[18:14:15.679][V][usb_host:056]: 	bDescriptorType 4
[18:14:15.679][V][usb_host:056]: 	bInterfaceNumber 1
[18:14:15.679][V][usb_host:056]: 	bAlternateSetting 0
[18:14:15.679][V][usb_host:056]: 	bNumEndpoints 2
[18:14:15.679][V][usb_host:056]: 	bInterfaceClass 0xa
[18:14:15.679][V][usb_host:056]: 	iInterface 0
[18:14:15.692][V][usb_host:042]: 		*** Endpoint descriptor ***
[18:14:15.692][V][usb_host:042]: 		bLength 7
[18:14:15.692][V][usb_host:042]: 		bDescriptorType 5
[18:14:15.692][V][usb_host:042]: 		bEndpointAddress 0x1	EP 1 OUT
[18:14:15.692][V][usb_host:042]: 		bmAttributes 0x2	BULK
[18:14:15.692][V][usb_host:042]: 		wMaxPacketSize 64
[18:14:15.692][V][usb_host:042]: 		bInterval 0
[18:14:15.699][V][usb_host:042]: 		*** Endpoint descriptor ***
[18:14:15.699][V][usb_host:042]: 		bLength 7
[18:14:15.699][V][usb_host:042]: 		bDescriptorType 5
[18:14:15.699][V][usb_host:042]: 		bEndpointAddress 0x81	EP 1 IN
[18:14:15.699][V][usb_host:042]: 		bmAttributes 0x2	BULK
[18:14:15.699][V][usb_host:042]: 		wMaxPacketSize 64
[18:14:15.699][V][usb_host:042]: 		bInterval 0
[18:14:15.719][D][usb_host:304]: Call on_connected
[18:14:15.721][D][usb_uart:331]: device connected
[18:14:15.730][D][usb_uart:031]: intf_desc: bInterfaceClass=02, bInterfaceSubClass=02, bInterfaceProtocol=01, bNumEndpoints=1
[18:14:15.740][D][usb_uart:041]: ep: bEndpointAddress=82, bmAttributes=03
[18:14:15.750][D][usb_uart:031]: intf_desc: bInterfaceClass=0A, bInterfaceSubClass=00, bInterfaceProtocol=00, bNumEndpoints=2
[18:14:15.760][D][usb_uart:041]: ep: bEndpointAddress=01, bmAttributes=02
[18:14:15.771][D][usb_uart:041]: ep: bEndpointAddress=81, bmAttributes=02
[18:14:15.771][V][usb_uart:081]: Found CDC-ACM device
[18:14:15.781][D][usb_uart:338]: Found 1 CDC-ACM devices
[18:14:15.783][D][usb_uart:390]: enter enable_channels
[18:14:15.791][D][usb_uart:398]: start_input for channel
[18:14:15.793][D][usb_uart:278]: call transfer_in epAddress: 0x81, MaxPacketSize: 64
[18:14:15.802][D][usb_uart:283]: transfer_in returns true
[18:14:15.802][W][component:547]: usb_host took a long time for an operation (189 ms)
[18:14:15.812][W][component:550]: Components should block for at most 30 ms
[18:14:15.826][D][usb_host:174][usb_task]: New device 1

As it looks, the transfer is submitted with usb_host_transfer_submit. There are absolutely no error messages and everything looks correct. The callback is just never called—no matter what, how much, or how fast I scan.

What did I forget? Is this even possible at all?

]]>https://community.m5stack.com/topic/8078/cores3-read-data-via-usb_uartRSS for NodeWed, 29 Apr 2026 04:48:08 GMTTue, 10 Feb 2026 21:14:46 GMT60