Customer:
Every time I try to upload a sketch to my Dasduino LITE I get an error message:
"avrdude: ser_open(): can’t set com-state for “\.\.COM3”
An error occurred while uploading the sketch"
I have followed all the installation instructions and searched forums but nothing has solved the problem.
Original message (Croatian)
Svaki puta kada pokušam uploadati sketch na svoj dasduino dobijem error poruku:
"avrdude: ser_open(): can’t set com-state for “\.\COM3”
An error occurred while uploading the sketch"
Pratio sam sve upute instaliranja i tražio po forumima ali ništa nije riješilo problem.
Originally submitted via email support on 26 February 2025. Migrated to the forum for community visibility.
Soldered Support:
Here are some things to try:
- Have you selected the correct COM port? COM3 is a serial port and should be where your Dasduino is, but if you have multiple ports available, try the others to find which one your Dasduino is on.
- Do you have the CH340 driver installed? It can be installed via this tutorial: https://soldered.com/hr/learn/instalacija-ch340-drivera-croduino-basic3-nova2/
- If avrdude is appearing, that’s the correct upload script for the ATTiny microcontroller on the Dasduino LITE, but verify that you have selected dasduino LITE as your board.
- Are you using the correct board definition? Here is the repository with board definitions for our boards, the README contains a tutorial on how to install: GitHub - SolderedElectronics/Dasduino-Board-Definitions-for-Arduino-IDE · GitHub
- Try a different USB cable and port.
- Do you have anything connected to your Dasduino? If it is loaded or shorted in any way, it won’t be accessible via USB. Try uploading code to an empty Dasduino.
Try these things and let us know if there’s any progress.
Original message (Croatian)
isprike na problemu i hvala na upitu 
Na pravom si mjestu. Idemo isprobati sljedeće:
Jesi li izabrao točan COM port? COM3 je serijski port i tako bi trebao izgledati port na kojem je Dasduino, ali jesi li u Tools izborniku izabrao točan, ako ih imaš više? Probaj ostale da nađeš na kojem PORT-u je Dasduino Imaš li CH340 driver? Može se instalirati preko ovog tutoriala: https://soldered.com/hr/learn/instalacija-ch340-drivera-croduino-basic3-nova2/ Ako se javlja avrdude, mislim da je to dobra skripta za upload na ATTiny, mikroupravljač na Dasduino LITE-u, ali provjeri jesi li izabrao dasduino LITE kao board. Koristiš li točan board definition? Evo repozitorija s board definitionima za naše board-ove, u README-ju se nalazi tutorial kako instalirati: GitHub - SolderedElectronics/Dasduino-Board-Definitions-for-Arduino-IDE · GitHub Probaj drugi USB kabel i port Imaš li nešto spojeno na Dasduino? Ako je na neki način opterećen ili shortan, neće se moći pristupiti preko USB-a. Probaj uploadati kod na prazan Dasduino
Probaj ove stvari pa javi ima li pomaka