Hi, if you are beginner to Arduino uno programming, You may face below 2 problem when you connecting your Arduino Board to your system to upload a code to test you then arduino problem uploading to board show error of ser_open(): can’t open device.COM1.

Arduino Error

1. An Arduino error occurred while uploading the sketch

2. ser_open(): can’t open device.COM1

An arduino error occurred while uploading the sketch:

When arduino not uploading the code and you face this arduino error compiling “An arduino error occoured while uploading the sketch” your debugger shows this complete error as in below box.

Arduino: 1.8.5 (Windows 7), Board: "Arduino Duemilanove or Diecimila, ATmega328P"

Sketch uses 928 bytes (3%) of program storage space. Maximum is 30720 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.
avrdude: ser_open(): can't open device "\\.\COM1": The system cannot find the file specified.

An error occurred while uploading the sketch

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

ser_open(): can’t open device.COM1

This Arduino error is happing due to you disabled the section of – “show verbose output during compilation”. You should enable these sections of compiling and uploading options.

This error most of them face during arduino code first time then arduino not uploading and show arduino error compiling the “ser_open(): can’t open device.COM1” – this is a arduino port error.

It is very common for all of them because they don’t chosen their board configuration details. They must select their board name and port in tools section. Unless they face the error as shown below.

avrdude: Version 6.3, compiled on Jan 17 2017 at 12:00:53
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is "C:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf"

Using Port : COM1
Using Programmer : arduino
An error occurred while uploading the sketch
Overriding Baud Rate : 57600
avrdude: ser_open(): can't open device "\\.\COM1": The system cannot find the file specified.

avrdude done. Thank you.

You must choose you board name and port number.

Goto tool section top menu -> choose the board name “which mention on your board” and according to that automatics the port sections will highlight choose one of them and check compiling and uploading the code, you may see the successful results.

When you uploaded your blinking code then you may see this successful text in your complier

Example: just I have uploaded the blinking code (files – examples – sample code – blinking)

avrdude: Version 6.3, compiled on Jan 17 2017 at 12:00:53
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is "C:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf"

Using Port : COM3
Using Programmer : arduino
Overriding Baud Rate : 115200
AVR Part : ATmega328P
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PC2
RESET disposition : dedicated
RETRY pulse : SCK
serial program mode : yes
parallel program mode : yes
Timeout : 200
StabDelay : 100
CmdexeDelay : 25
SyncLoops : 32
ByteDelay : 0
PollIndex : 3
PollValue : 0x53
Memory Detail :

Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
eeprom 65 20 4 0 no 1024 4 0 3600 3600 0xff 0xff
flash 65 6 128 0 yes 32768 128 256 4500 4500 0xff 0xff
lfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
hfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
efuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
lock 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00

Programmer Type : Arduino
Description : Arduino
Hardware Version: 3
Firmware Version: 4.4
Vtarget : 0.3 V
Varef : 0.3 V
Oscillator : 28.800 kHz
SCK period : 3.3 us

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e950f (probably m328p)
avrdude: reading input file "C:\Users\TECHMA~1\AppData\Local\Temp\arduino_build_321343/Blink.ino.hex"
avrdude: writing flash (948 bytes):

Writing | ################################################## | 100% 0.16s

avrdude: 948 bytes of flash written
avrdude: verifying flash memory against C:\Users\TECHMA~1\AppData\Local\Temp\arduino_build_321343/Blink.ino.hex:
avrdude: load data flash data from input file C:\Users\TECHMA~1\AppData\Local\Temp\arduino_build_321343/Blink.ino.hex:
avrdude: input file C:\Users\TECHMA~1\AppData\Local\Temp\arduino_build_321343/Blink.ino.hex contains 948 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.13s

avrdude: verifying ...
avrdude: 948 bytes of flash verified

avrdude done. Thank you.

After setting these options check the led blinking code

// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital pin LED_BUILTIN as an output.
pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
digitalWrite(LED_BUILTIN, HIGH); // turn the LED on (HIGH is the voltage level)
delay(1000); // wait for a second
digitalWrite(LED_BUILTIN, LOW); // turn the LED off by making the voltage LOW
delay(5000); // wait for a second
}

if you still not solved the problem, comment below what arduino error you facing. Thank You