Bootloader is Deleted When Programming to ATSAMD21G18 Controller

[berkay_91]

Hello, I apply what is written on both sites I added the link to, upload the bootloader to the controller named ATSAMD21G18, set the Fuse bit named "BOOTPROT" to "8192 Bytes" value again but bootloader is deleted, the program does not work and the COMPORT of the controller does not appear again... Can you help?

https://learn.adafruit.com/how-to-program-samd-bootloaders/setup

https://atmega32-avr.com/atsamd21g18-bootloader-with-j-link-debugger/

 

[berkay_91]

solution

If there is no Crystal (32.768 kHz) for the Internal RTC Unit of the SAMD21G18 Processor in the Designed Board

C:\Users\Berkay\AppData\Local\Arduino15\packages\adafruit\hardware\samd\1.7.10

The line in the file "boards" in the file path
adafruit_feather_m0_express.build.extra_flags=-D__SAMD21G18A__ -DARDUINO_SAMD_FEATHER_M0 -DARDUINO_SAMD_FEATHER_M0 -DARDUINO_SAMD_ZERO -DARM_MATH_CM0PLUS {build.usb_flags}

should be changed as below
adafruit_feather_m0_express.build.extra_flags=-D__SAMD21G18A__ -DCRYSTALLESS -DARDUINO_SAMD_FEATHER_M0 -DARDUINO_SAMD_FEATHER_M0 -DARDUINO_SAMD_ZERO -DARM_MATH_CM0PLUS {build.usb_flags}