Serial Monitor difficulty-Unavailable

I’m running the Arduino IDE 1.6.12 and 101 Core 1.07 on Windows 10. After a successful upload I click the serial monitor and often receive: “Board at COM2 Unavailable.” When go into the Device Manager I’m seeing that COM2 has the value of Arduino 101 Serial Monitor (COM 2). Other times the Serial Monitor window will launch, but it contains nothing although the sketch prints to it.

When I go to the IDE and do Tools|Get Board Info I’m seeing a popup with BN, VID, PID, and SN read correctly from the COM2 port. Also, at the lower right of the IDE is: Arduino 101 on Com2

I have had success with this board on this computer in the past with earlier versions of the IDE and 101 Core. I don’t have this issue with my Mega 2560 board on this computer.

Any ideas for what I need to do to get things running smoothly?

Thank you in advance.

Vic

Would you like to post your sketch and i will try it here ?

Don't forget to use code tags please.

Bob,

Thank you. The sketch is working with some difficulty. The sketch is stock Adafruit BME280 from Github with no modifications yet. When I upload, I sometimes get Com2 unavailable. But if I persist, it will upload. Then, almost 100% of the time when I click the serial monitor I will get Com2 unavailable. But with persistence and a number of mouse clicks, I will usually get the serial monitor.

At this point maybe I should just consider that this happens with the Arduino 101. There should not be a speed problem. The computer I'm using runs an Intel I7.

I do not experience this with the Mega 2560. The handy thing about the 101 is that it is a 3.3 Volt device and I don't need level shifting.

Love to get your thoughts. Basically, I'm going to live with it unless you can think of magic.

Best regards and thank you again,

Vic

My 101 can be quite temperamental if I want serial output in the web based IDE "CREATE" and I do think its a quirk of the board myself (I don't work for Arduino)

Mine wont play at all on USB 3.0 and I did notice that a couple of my USB cables didn't seem to work as well as others on it and the MKR1000 even though they work fin on other Arduinos.

My normal AVR's mega uno etc don't show the quirks of the MKR and 101 just as you have found.

Both the MKR and 101 are still relatively new boards and I know they updated a couple of things on the MKR in the cores which helped make it a bit more reliable so hopefully they do the same with the 101.

Interesting, Bob. Thankyou for letting me know that your 101 is a little picky. USB3 ----- That's the only thing I have on this HP notebook. I may try changing cables. Right now there is a nice short one going to the device.

Vic

Yes USB is well documented as being an issue with not just 101 or mkr's but other Arduinos as well

That's not to say all usb 3.0 is bad but it seems some implementations and usb chipsets might be worse than others and a few even work ok... you sound like one of the lucky ones.

Vic,

vdolcourt:
I'm running the Arduino IDE 1.6.12 and 101 Core 1.07 on Windows 10. After a successful upload I click the serial monitor and often receive: "Board at COM2 Unavailable." When go into the Device Manager I'm seeing that COM2 has the value of Arduino 101 Serial Monitor (COM 2). Other times the Serial Monitor window will launch, but it contains nothing although the sketch prints to it.

I had not read your post until after I posted a similar question a few minutes ago. (Searches of the Forum didn't turn up this thread.)

Is your problem with the Serial Monitor related to how long you wait after uploading your Sketch before opening the Monitor? I have found that I often have to wait a minimum or 15 seconds after uploading the Sketch before trying to open the Serial Monitor. If I don't wait long enough, I too, get the COM port is not available message. I can then Reset the 101 and wait for a longer time and the Monitor will then successfully open and operate correctly.

What happens if you wait for a longer time before opening the Monitor? Does that help on your set-up as it does mine?

John

Hi John,

What I am seeing is inconsistency. Pretty much (meaning most of the time) if I wait 10 - 15 seconds the serial monitor comes up, sometimes after a couple of clicks. But I have gotten other things like nothing or "Error while setting serial port parameters 9,600 N * 1". Sometimes I get serial port unavailable when I try to upload.

Thanks for following up.

Vic

I had good luck in using a 3rd Party Serial Terminal like Cool Term, Putty or Terraterm. For linux screen works as well. If you need to log the terminal output, picocom, minicom and cutecom are other alternatives.

The catch is that you have to disconnect the 3rd party Serial Terminal first, before you can upload but I find that once I see the SUCCESS in the IDE, I can connect after 5 second reliably than the built-in Serial Monitor. They have other benefits as well, like the ability to save for logging purposes or remembering strings for input.

Also try the 115200 setting rather than 9600.

If you just want to stick with the built-in serial monitor just keep it open. It will be grayed out and disconnect when you push upload and will be available faster and less frustrating than opening it again.

On my Windows PC that has only USB3.0 capability, I can only upload to the 101 board is if the serial monitor is x'ed out. Otherwise, the upload waits and waits and .....

I would never say that this is the operation across all OS or even all USB ports. But this is what I have observed.