I’ve been successfully using the Arduino, uploading and testing new projects easily. When I first started, I found that I had to connect the USB via COM5, and it has worked consistently on COM5 at 9600. Between tests I unplug the USB cable, change the breadboard, and plug it in again. But now, upload says it can’t find the COM port, and the only option I find under Tools->COM port is COM1, which doesn’t work. Why did it change? Do I need to uninstall the driver and reinstall? Thanks…
It’s my experience that when a device is not plugged into a port the specific com port will not be listed. So if you do have a cable plugged into that port and the associated COM port is not listed that probably means that the interface hardware is not working as intended, the ftdi chip is not working. Sometimes a powercycle of both the arduino end and the PC end will help solve the issue. I am not particularly well versed in the computer to hardware interfaceing world but that is my best guess as to what is going on.
Good luck.
I really appreciate the suggestion. After further testing, I discovered the problem, and your explanation led me in the right direction. It turns out that I had a servo hooked up with the polarity reversed on the power connector. This caused the Arduino board to fail (power down) within a few seconds after applying power, so the board connected to the USB initially, then immediately disconnected. When it disconnected, the COM5 port was no longer available, as you suggested. When I corrected the power polarity on the servo, it all started working. So, my setup is back to normal now.
Thanks!