However from within the Arduino IDE, I uploaded some code which directly modifies some TCC0 control registers and interrupt ISR (as defined within Microchip’s TCC0.h component header file, as also seemingly used by Seeed’s TimerTCC0 XIAO driver); I can no longer access the device via its USB interface even after reseting the device by tapping the reset pin quickly twice; which results in the yellow led adjacent to the green power led, pulsing softly at about 4 hertz, but never blinking slowing as it should if the boot loader has successfully brought up its USB host interface port; as if it’s trying to reset, but the default boot loader keeps being interrupted by something?
I suspect my code corrupted some system state which the boot-loader relies upon, but which should not happen if the boot-loader only executes after the system was fully hw-reset, and only executes user partition code if not receiving a second reset-pulse within some period of time?
So as it stands now, the device is useless, which begins executing my corrupt code before it locks up, and apparently can’'t be successfully reset to execute the boot-loader resulting in a functional USB interface to the host Arduino IDE?
Any suggestions would be appreciated.
(Please also consider improving the robustness of the boot-loader, as it should always work, regardless of what state is possibly corrupted by user-code, to help prevent this in the future.)
I was attempting to configure TCC0 as a 24bit 1MHz wrap-around counter which would generate an interrupt upon matching a value in its compare register (while the counter continues to count). Which the TimerTCC0 driver appears not to currently support. So also please consider updating this or another driver to enable this, or please suggest a possibly different approach I should consider.
The J-Link EDU mini can be had for < $20 for non-commercial use, and can be used to re-flash the boot-loader if necessary; you’ll need to either solder wires to the SWD pads on back of the XAIO, or construct some sort of a jig; but I’d try rebooting your host computer first, as it appears sometimes the host’s USB Driver Deamon gets confused, and won’t properly recognize the XIAO’s serial port from time to time (at least on my Mac).
Sorry I don’t know about use of the Raspberry Pi as an SWD programmer, but Segger offers free basic SW for use with their J-Link product, capable of re-flashing the XIAO boot-loader. Maybe some one else can answer your question.
Oh no that’s actually helpful thank you. I was thinking there was going to be some standard
SWD commands or something I’d need to learn. Looks like this OpenOCD library for Raspberry Pi can do it. I’ll just need to learn how OpenOCD does the flashing process.
I’m trying to repair my 3 XIAO’s. Something about the way I use them and my Wio lite MG126 has causede me to be unable to program any of them. I’ve been through
resetting the devices
re-connecting the devices
rebooting my PC
resetting the products twice quickly
uninstalling the devices from device manager
deleting the usb controller
removing the registry entries associated with VID/PID
and I still can’t upload to them.
Now I’m trying Black Magic Probe (Jeff Probe BMP Clone). I’ve soldered connections to Reset, SWCLK and SWDIO and have connected to them to the appropriate pins on the included JTAG ribbon cable. I performed a continuity check on them and am positive the pins are correct. I’m definitely connecting power to the BMP as well as powering the XIAO/Wio using external pwoer. I also connected the UART interface to the appropriate TX/RX pins using a grove connector.
The problem is that I’m stupid and don’t know
WHERE to find the “bootloader” source file that needs to get uploaded
HOW to send it.
I actually don’t even know WHAT the “bootloader” does.
I thought that resetting twice quickly puts the device into bootloader mode but I actually have no idea what that is or why it would be used.
There are so many programming devices, protocols, toolchains, firmware, flags, and enough documentation to have sent me down rabbit holes for over a month now.
I don’t care what method I use but I need to find A method of programming the bootloader(?)
In Arduino IDE I don’t know what to do to program the target.
I followed the VSCode/PlatformIO instructions and it does communicate through CLI so I see the target system and upload port but it hangs when it’s sending firmware.bin.
Programming using SWD in Atmel studio with a Blackmagic Probe is a total mystery.
Things like baud rates, GDB commands, bootloader file location, would be good to see as a how to.
I understand that this probably isn’t a Seeedstudio manufacturing issue but I was hoping to leverage any debugger/uploading experience anyone has.
I’ve asked for some direction on many different forums. It just so happens that the problems people are having on this forum are exactly like mine.