It means something disrupted the connection between the arduino and PC. Usually its unshield/bad wiring, or some other source of EMI, but there are a lot of possibilities, including 10m boosted USB cable. If you have callbuttons make sure they're wired right. And make sure all your connections are rock solid.

There's lots of posts regarding using ferrite cores(???) and other such things to clean up your signal and prevent the dreaded COM lost message. I'll leave it to smrtr people than I to take it from here...

-Dave

 

So what I did was close RC then unplug usb cable for few seconds plug it back in start RC and then it work good again.

 

Is yours a permanent track or do you have to set-up the computer for each meeting?

We have to set up for each meeting and found the USB connection became loose through frequent plugging and unplugging.

This made it unreliable and subject to vibration.

Several years ago I added strain relief to the USB connection at both ends and have not had that problem since.

You can also tighten up the connections in both the USB ports - particularly at the PC/Laptop end. (We also use Win7 and a long USB lead but I think ours is only 5m. I'd have to measure it.)

 

It is a permanent track. Wondered if the boosted usb cable was the problem and whether a not boosted one would be better.

 

I have found that not all USB cables are created equal. Some of the cheap ones are just that cheap and nasty, with poor contacts or loose.
I now only use cables of good quality with Ferrite core on them.Also have a small capacitor across each lane. No problems since.

 

Could the problem be interference and if so what could cause the interference?

 

Hi mark, one of the worst things for interference are electric motors, unfortunately we need them in our hobby.

If your cable is under 5m you should be ok with an unpowered usb cable. As Phill states a better shielded usb with ferrites will probably be better.

I've seen people do all sorts to fix these sorts of issues. Contact cleaner on usb sockets, capacitors across the lanes (in olden days didn't all cars have caps fitted?). I've seen people try to shield Trackmate interfaces in a metal biscuit tin (make sure it can't short).

I've switched solely to Bluetooth now, so got rid of USB stuff completely.

Of course this could just as easily have been a pc glitch or power surge, which I'm sure we all get occasionally!

I'd be tempted to leave everything as it is and see if it is a recurring issue.

From memory I'd say at the club we'd have a trackmate/pc issue once every 10 or 20 meetings.

 

Don't know why this went missing, but meant to say you could always try adding ferrites to any existing cables, they seem pretty cheap, not sure if anyones ever tried them:-

https://uk.rs-online.com/web/p/products/7740639/?grossPrice=Y&cm_mmc=UK-PLA-DS3A-_-google-_-PLA_UK_EN_Passive_Components-_-Ferrite_Cores%7CFerrite_Sleeves-_-PRODUCT+GROUP&matchtype=&pla-394211284716&gclid=CjwKCAjw-8nbBRBnEiwAqWt1zQoNZPyl9N0BrFVSLijwtF-j1La2cugSvovJJBNRWmC8iFFPchv5qhoCeu4QAvD_BwE&gclsrc=aw.ds

 

Several guys on Auslot are using them seem to work OK.

 

Thanks will give it a try.

 

So what's a good make of usb cable? In case we need a different one.

 

Thanks for this post people! I too, was having this same problem, presently using "DragRC v0.0.0.20". I dug thru my box of various USB cables and finally came upon one of much higher quality that seems to keep the software operational without the unplugging /plugging in thang. Unfortunately, I do not know brand or specs on it but did have a successful fix using a different USB cable.

Thanks again!

 

well added ferrites to each end of cable and did not get the problem at the club night. So hopefully all fixed.

 

could having wifi on to stream the info to smartphones and tablets cause the problem?

 

Have put New uno board in it works great with no problem at all. But if we turn laptop wifi on to stream to phones or tablets that's when we get lost protocol communication.

Now it could be not a problem with rc but windows losing communication with the uno board so how to fix it so we can use it with wifi on and no problem.

 

Anyone know the full description of the protocol in the ino file please as someone on the arduino forums thinks it is a little wonkey.

 

Hi

this may be unrelated but my ex windows phone kept corrupting my laptop wifi, it showed up when trying to download music files onto the laptop, I found out by accident that turning wifi off on the phone stopped it happening, eventually I found a setting in the phones wifi setting that cured it, b%=$y Windows

 

What I can tell you is COM lost means the PC can not talk to the arduino through the serial connection. A LOT of things can cause this. Things like bad USB cables or EMI can cause the arduino itself to drop the connection, but windows nonsense could also do it on the Windows side. Things like virus protection are very bad for serial connections. I have no clue why turning wifi on would cause issues. Certainly it works in general. It's how I run...

For your information, RC detects the loss because it stops receiving the "heart beat" from the arduino, but RC has no way of figuring out what or why the heart beat stopped coming in. It could be that the arduino is sending it and the PC isn't receiving it or that the arduino is not sending it at all. Hmmmm. Maybe I can put something into the sketch that can be used to troubleshoot. Like allowing RC to configure a debug pin/pins which blink when the heart beat is sent or some such... That would at least give us some information.

One thing you can do now is when you get COM lost go into your device manager and see if windows can still see the COM port. If it can't that's a problem... Although to complicate matters, we could have a scenerio in which the COM port is killed for some reason and then comes back. In that case Windows would see it but RC wouldn't be using it and it would be hard to identify that it even happened....

 

Hi

We had a stange problem in our club. Fault count, fall out of control and other things.
Even the PC couldn't start up.
Then one day we found out that the fan in the PC was running dispite the PC was turned off?
Root cause was that power was running backwards from the arduino board.
The arduino has it's own supply and the stop diode to the USB power was shorted.
By removing the diode it has worked well since.

Regards Bjarne

 

So how would virus protection affect com port?

 

Virus protection software can do horrible things to track interfaces. It varies based on how they're setup and such but regarding a serial connection some virus protection software will see the serial port as a security risk and prevent traffic going to/from it.

At very least when you're first setting up a track interface, if you're having problems you should completely disable any virus protection software. Once you get things working you can turn it back on and see if things continue to work...

 

Well I turned Virus protection software of and then tried again with wifi on and after about 3 hours 15min get the message lost protocol communication. So I
looked in device manager and windows said this device is working properly and also it still shows as com port 8 in rc as well.

But to make it work great it is best to restart the laptop.

 

Is that 3 hours an improvement or is that how long it took before? I'm still trying to figure out how I can put something into the arduino side that will help debug COM lost. Usually its a matter of EMI and such messing up the arduino. This is the first time I've heard of WiFi being linked to it in any way, shape or form...

 

3 hours is probably about the same as before but sometimes it can be shorter than 3 hours. It is just weird that with wifi turned of we get no problems.

 

Yeah I honestly don't even have a guess as to why that is... How sure are you that it doesn't happen with wifi off? Have you waited like 6 hours? 3 hours is a long time and maybe the times you ran with out wifi just happened to go longer?