# Can’t upload code on MKRZero **URL:** \ **Category:** MKR Zero\ **Created:** [May 22, 2022, 8:38am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434 "2022-05-22T08:38:44Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![stefa24](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/stefa24/32/214229_2.png) [@stefa24](https://forum.arduino.cc/u/stefa24)\ **Post date:** [May 22, 2022, 8:38am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/1 "2022-05-22T08:38:45Z")
Hello Following old posts I tried the "quickly double tap the reset button" that will put it into bootloader mode on another COM port and allow me to upload as normal ```cpp Sketch uses 39216 bytes (14%) of program storage space. Maximum is 262144 bytes. Global variables use 3884 bytes (11%) of dynamic memory, leaving 28884 bytes for local variables. Maximum is 32768 bytes. Atmel SMART device 0x10010005 found Device : ATSAMD21G18A Chip ID : 10010005 Version : v2.0 [Arduino:XYZ] Dec 20 2016 15:36:46 Address : 8192 Pages : 3968 Page Size : 64 bytes Total Size : 248KB Planes : 1 Lock Regions : 16 Locked : none Security : false Boot Flash : true BOD : true BOR : true Arduino : FAST_CHIP_ERASE Arduino : FAST_MULTI_PAGE_WRITE Arduino : CAN_CHECKSUM_MEMORY_BUFFER Erase flash done in 0.870 seconds Write 39216 bytes to flash (613 pages) [==============================] 100% (613/613 pages) done in 0.304 seconds Verify 39216 bytes of flash with checksum. Verify successful done in 0.035 seconds CPU reset. ``` ---
**Author:** ![in0](https://avatars.discourse-cdn.com/v4/letter/i/77aa72/32.png) [@in0](https://forum.arduino.cc/u/in0)\ **Post date:** [May 22, 2022, 8:45am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/2 "2022-05-22T08:45:05Z")
Hi @stefa24. Please provide a detailed description of the problem. The output you shared appears to be from a successful upload. ---
**Author:** ![stefa24](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/stefa24/32/214229_2.png) [@stefa24](https://forum.arduino.cc/u/stefa24)\ **Post date:** [May 23, 2022, 8:27am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/3 "2022-05-23T08:27:03Z")
Hi ```cpp The output you shared appears to be from a successful upload. ``` I shared for information about my ZERO The problem I met I wasn t able to make any upload after some updates, below the message after several minutes later I lunched upload command ```cpp Arduino: 1.8.19 (Windows 10), Board: "Arduino MKRZERO" Sketch uses 39216 bytes (14%) of program storage space. Maximum is 262144 bytes. Global variables use 3884 bytes (11%) of dynamic memory, leaving 28884 bytes for local variables. Maximum is 32768 bytes. An error occurred while uploading the sketch This report would have more information with "Show verbose output during compilation" option enabled in File -> Preferences. ``` ---
**Author:** ![MartinL](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/martinl/32/216911_2.png) [@MartinL](https://forum.arduino.cc/u/MartinL)\ **Post date:** [May 23, 2022, 10:12am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/4 "2022-05-23T10:12:34Z")
Hi @stefa24 Have you attempted double tapping the reset button, selecting the bootloader's COM port and uploading the code oncemore? The issue with boards that use their native USB for uploading code, is that they require the current program (sketch) to be functioning, in order to allow the next to be uploaded. If the current program crashes for whatever reason, it prevents the auto-upload from working correctly. When this happens, it's necessary to manually activate bootloader mode by double tapping the reset button. This is in contrast to boards such as the Arduino Uno/Nano/Mega that use a co-processor or FTDI USB-to-Serial chip. This device acts as an intermediary and keeps the COM port connection alive no matter what the current state of the main microcontroller. ---
**Author:** ![stefa24](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/stefa24/32/214229_2.png) [@stefa24](https://forum.arduino.cc/u/stefa24)\ **Post date:** [May 24, 2022, 7:27am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/5 "2022-05-24T07:27:39Z")
> [@MartinL](#): > > Have you attempted double tapping the reset button, selecting the bootloader's COM port and uploading the code oncemore? Yes I did thanks for the explanation ---
**Author:** ![MartinL](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/martinl/32/216911_2.png) [@MartinL](https://forum.arduino.cc/u/MartinL)\ **Post date:** [May 24, 2022, 7:50am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/6 "2022-05-24T07:50:40Z")
Hi @stefa24 Have you tried disconnecting the board from any external circuitry and uploading a simple "blink" sketch? Does double tapping the reset button actually place the board into bootloader mode and does the new COM port appear in the Arduino IDE? ---
**Author:** ![stefa24](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/stefa24/32/214229_2.png) [@stefa24](https://forum.arduino.cc/u/stefa24)\ **Post date:** [May 24, 2022, 11:47am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/7 "2022-05-24T11:47:20Z")
> [@MartinL](#): > > Have you tried disconnecting the board from any external circuitry and uploading a simple "blink" sketch? didn t worked > [@MartinL](#): > > Does double tapping the reset button actually place the board into bootloader mode and does the new COM port appear in the Arduino IDE? yes it does ---
**Author:** ![MartinL](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/martinl/32/216911_2.png) [@MartinL](https://forum.arduino.cc/u/MartinL)\ **Post date:** [May 24, 2022, 11:55am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/8 "2022-05-24T11:55:54Z")
Hi @stefa24 > [@stefa24](#): > > didn t worked Ok, have you selected the bootloader COM port in the Arduino IDE? On the menu bar select Tools-\>Port, then select the new COM port for your board. If you check a second time, the COM port should be ticked. Then try uploading a basic sketch with visual feedback, such as "blink" oncemore. ---
**Author:** ![stefa24](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/stefa24/32/214229_2.png) [@stefa24](https://forum.arduino.cc/u/stefa24)\ **Post date:** [May 24, 2022, 11:56am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/9 "2022-05-24T11:56:46Z")
ok I did, now I can upload the sketch ---
**Author:** ![MartinL](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/martinl/32/216911_2.png) [@MartinL](https://forum.arduino.cc/u/MartinL)\ **Post date:** [May 24, 2022, 11:57am UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/10 "2022-05-24T11:57:12Z")
@stefa24 Is the LED on your board blinking? ---
**Author:** ![MartinL](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/martinl/32/216911_2.png) [@MartinL](https://forum.arduino.cc/u/MartinL)\ **Post date:** [May 24, 2022, 12:09pm UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/11 "2022-05-24T12:09:30Z")
> [@stefa24](#): > > ok I did, now I can upload the sketch @stefa24 Once you've uploaded the code with the board in bootloader mode, it will run the sketch and return to normal operation. Auto-upload will start working again, (although you might have to select the new COM port in the IDE, as you just did for the bootloader). ---
**Author:** ![stefa24](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/stefa24/32/214229_2.png) [@stefa24](https://forum.arduino.cc/u/stefa24)\ **Post date:** [May 24, 2022, 12:49pm UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/12 "2022-05-24T12:49:33Z")
I did Now the board is working again thanks ---
**Author:** ![MartinL](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/martinl/32/216911_2.png) [@MartinL](https://forum.arduino.cc/u/MartinL)\ **Post date:** [May 24, 2022, 2:09pm UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/13 "2022-05-24T14:09:57Z")
@stefa24 Glad to hear your board's up and running again πŸ˜ƒ. ---
**Author:** ![stefa24](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/stefa24/32/214229_2.png) [@stefa24](https://forum.arduino.cc/u/stefa24)\ **Post date:** [May 24, 2022, 7:59pm UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/14 "2022-05-24T19:59:12Z")
thanks to you all πŸ˜€ ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [November 20, 2022, 7:59pm UTC](https://forum.arduino.cc/t/can-t-upload-code-on-mkrzero/994434/15 "2022-11-20T19:59:36Z")
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