RIOT/tests/sys/usbus_board_reset

Overview

This test represents a simple shell application that can be used to test the USB board reset function (module usb_board_reset) via the USB CDC ACM interface.

It can be used to reset the board to restart either the application or the bootloader if supported using the usb_board_reset module.

The test application requires that the board provides USB peripherals (feature periph_usbdev).

Usage

Once the test application is flashed, the board should be detected. The output of command

dmesg

should look like the following and should show the USB DC ACM interface:

[1745182.057403] usb 1-4.1.2: new full-speed USB device number 69 using xhci_hcd
[1745182.160386] usb 1-4.1.2: New USB device found, idVendor=1209, idProduct=7d01, bcdDevice= 1.00
[1745182.160390] usb 1-4.1.2: New USB device strings: Mfr=3, Product=2, SerialNumber=4
[1745182.160392] usb 1-4.1.2: Product: arduino-mkr1000
[1745182.160393] usb 1-4.1.2: Manufacturer: RIOT-os.org
[1745182.160395] usb 1-4.1.2: SerialNumber: 6B6C2CA5229020D8
[1745182.170982] cdc_acm 1-4.1.2:1.0: ttyACM0: USB ACM device

Note: The interface ttyACM0 could be different depending on which other USB CDC ACM devices are already in use.

For boards that use the USB CDC ACM interface as STDIO (module stdio_cdc_acm), this interface is used for the test application. Otherwise the test application creates a simple USB CDC ACM interface without any functionality except the USB board reset function.

When the USB CDC ACM interface is initialized, the stty command can be used to reset the board, for example:

stty -F /dev/ttyACM0 raw ispeed 600 ospeed 600 cs8 -cstopb ignpar eol 255 eof 255

should reset the board and restart the application, while

stty -F /dev/ttyACM0 raw ispeed 1200 ospeed 1200 cs8 -cstopb ignpar eol 255 eof 255

should reset the board and start the bootloader. The latter requires that the bootloader supports this.