![Solved: Arduino - avrdude: ser_open(): can't open device "\\.\COM3": The system cannot find the file specified. | Experts Exchange Solved: Arduino - avrdude: ser_open(): can't open device "\\.\COM3": The system cannot find the file specified. | Experts Exchange](https://filedb.experts-exchange.com/incoming/2020/02_w07/1443216/new-1.png)
Solved: Arduino - avrdude: ser_open(): can't open device "\\.\COM3": The system cannot find the file specified. | Experts Exchange
![Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it. Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.](https://gyorgybalassy.files.wordpress.com/2020/10/arduino-port-properties_thumb.png?w=364&h=455)
Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.
![avrdude: ser_open(): can't open device "unknown": No such file or directory - Installation & Troubleshooting - Arduino Forum avrdude: ser_open(): can't open device "unknown": No such file or directory - Installation & Troubleshooting - Arduino Forum](https://europe1.discourse-cdn.com/arduino/original/4X/7/5/f/75fb84cceb041233e9659b624d0a93a2ced922b0.png)
avrdude: ser_open(): can't open device "unknown": No such file or directory - Installation & Troubleshooting - Arduino Forum
Flash Firmware fails: ser_open(): can't open device "/dev/ttyUSB0" · Issue #6610 · prusa3d/PrusaSlicer · GitHub
![Arduino Nano - "avrdude: ser_open():system can't open device "\\.\COM1": the system cannot find the file specified" - Stack Overflow Arduino Nano - "avrdude: ser_open():system can't open device "\\.\COM1": the system cannot find the file specified" - Stack Overflow](https://i.stack.imgur.com/1kNPb.png)
Arduino Nano - "avrdude: ser_open():system can't open device "\\.\COM1": the system cannot find the file specified" - Stack Overflow
![Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it. Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.](https://gyorgybalassy.files.wordpress.com/2020/10/arduino-serial-port-in-device-manager.png)
Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.
![avr - ATMEL STUDIO: avrdude.exe: ser_open(): can't open device - Electrical Engineering Stack Exchange avr - ATMEL STUDIO: avrdude.exe: ser_open(): can't open device - Electrical Engineering Stack Exchange](https://i.stack.imgur.com/aIhog.png)
avr - ATMEL STUDIO: avrdude.exe: ser_open(): can't open device - Electrical Engineering Stack Exchange
![Arduino Nano - "avrdude: ser_open():system can't open device "\\.\COM1": the system cannot find the file specified" - Stack Overflow Arduino Nano - "avrdude: ser_open():system can't open device "\\.\COM1": the system cannot find the file specified" - Stack Overflow](https://i.stack.imgur.com/cx8c7.png)
Arduino Nano - "avrdude: ser_open():system can't open device "\\.\COM1": the system cannot find the file specified" - Stack Overflow
![Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it. Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.](https://gyorgybalassy.files.wordpress.com/2020/10/arduino-port-selection.png)
Can't open device "\\.\COM4": Access is denied error when uploading a sketch from Arduino IDE | I learned it. I share it.
![18.04 - Uploading code to arduino gives me the error: "avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied" - Ask Ubuntu 18.04 - Uploading code to arduino gives me the error: "avrdude: ser_open(): can't open device "/dev/ttyACM0": Permission denied" - Ask Ubuntu](https://i.stack.imgur.com/ifRmx.png)