Robot v Xmas tree lights

Factual Questions
1

No, this isn’t a new Marvel adventure, this is a real question about a technical problem I am facing.

I have a Stihl robot lawn mower that is connected to the internet via my home wifi so that I can manage settings etc remotely. This has proven to be a real headache and I am sort of wishing I had stayed with my previous robot which did not have internet connectivity (it was stolen a couple of months ago). The problem is that I am getting lots of errors with the remote connection, most often with app telling me that the robot is ‘offline’ when it wasn’t or that the mowing was interrupted by rain when it was completely dry and sunny out. The robot can still be managed manually via the local menu, but it is a pain and I cannot do anything via the app. And sometimes when the robot goes to charge it goes ‘offline’ and stays that way. I then need to restart it manually.

I spoke to Stihl technical support and they asked me whether I have anything metal that might be interfering with the communication between the robot and the wifi. I thought back to when the problem started and remembered that we had strung up some outdoor Christmas tree lights on the terrace last month for my wife’s birthday party. The problems started the next day. The lights are about 8 feet off the ground and 30 feet long, and are directly between the robot docking station and the wifi router in the house (with a large window in between).

What do you think? Could the lights be causing the problems? I have tried taking them down (laying the lights flat on the terrace) and it seems to improve things, but it is still not perfect.

(posting this in FQ as some electrical folks might have a factual answer, but am fine if IMHO is more appropriate)

2

A narrow metal wire shouldn’t make any difference. The Stihl tech support person (or rather, whoever wrote the tech support person’s script) was probably thinking of something that’d form a continuous barrier, like aluminum siding.

3

hmm. What about venetian blinds? The window in question has blinds which at the current moment are closed (it is very hot outside). I can’t really tell what they are made of, the material is white and semi-rigid, and may be aluminum with some white coating?

4

It might be easiest to move a wireless AP (or even your phone, as a hotspot) for a little while to see if that eliminates the problem. If it fixes it, it’s just a matter of dealing with the signal issue. If it makes no difference, it’s more than likely to be a Stihl issue and you can let them know what you tried.
If you have the option, use 2.4GHz. It’s slower, which shouldn’t matter here, but it’ll go further.

5

Having the problem start after the light went up seems to be a smoking gun to me. I’d say try taking the lights completely out of the equation. Unplug them, take them down, and take them inside.

6

I would do a connectivity test after each stage in the process just to puzzle out what element of the process is the source of the interference and perhaps avoid “oversolving” and doing more work unnecessarily.

7

Do some internet speed tests with your phone. If you google “speed test”, google has one of it’s own you can do in the browser. Do one in the house and then a few in the yard where the mower is. There’s likely going to be some slowdown in the yard. If it’s really slow, then it may be too slow or problematic for the mower. Adding a range extender so the yard is covered may help in that case.

8

I don’t think the lights are the problem.

I left something out when I wrote this. I meant to say you should temporarily move a wireless AP outside (or use your phone as a hotspot) so it’s closer and has a line of sight.
If things work, it’s likely a signal issue. If it still doesn’t work, it’s a Stihl issue, probably.

9

I know nothing about RF engineering, but have 30+ years experience in commercial software debugging. When a system is working fine one day, but develops problems the next, the first question is always “What’s changed?”. (Of course the customer always says nothing has changed, but that’s a subject for a pit thread.) In this case the change that happened was the addition of the Christmas lights, so that’s the logical place to start the debugging.

10

In the OP you mentioned getting errors with the “remote connection” but still being able to use the “local menu”.
Can you explain what you mean by that? Or more specifically, what you mean by ‘local menu’?

I ask because if by ‘local menu’ you mean an app on your phone that talks to the mower without some type of cloud connection, then that changes things. If the mower can get on to your network, but you can’t connect to it remotely, it could be a firewall/port forwarding issue, a problem with Stihl’s cloud or any number of other things.

So, I think the first question that really needs to be answered is…can your mower make and maintain a stable wifi connection to your home network?

(OTOH, if ‘local menu’ means something like a control panel on the lawnmower itself, or even an adhoc/bluethooth/NFC connection then disregard this)

Also, try changing the wifi channel on your router. That might help if the mower is getting interference from the neighbor’s wifi.

11

Just a bit of an update.

I completely removed the Xmas tree lights, and the problem continued. I also opened the blinds completely. No improvement. So I guess they were not interfering with the signal.

So I called the dealer to have a look, and he tested the wifi connection. It was fine.

So he called Stihl, who agreed to replace the wifi card. They did that. The dealer brought the robot back today and reconnected it. So far nothing has changed. It still goes offline.

One thing that occurred to the dealer is that the Apple AirTag that I put under the hood to track the robot in case of theft might have interfered with the wifi connection to the house. The AirTag was still there today when the dealer brought the robot back. So I removed the AirTag, but the robot is still going offline. Now the dealer is suggesting that the Airtag fried the new wifi card.

What do you think? Is that a possibility?

12

The airtag didn’t fry anything. Airtags don’t do that anymore than your cell phone would. They communicate via bluetooth, NFC and Ultra Wide Band. I’ve never heard Ultra Wide Band but a cursory skimming of it’s wiki page doesn’t suggest it’s any more likely to fry nearby electronics than any other device that can communicate wirelessly.

So, if it can connect to wifi at the dealer’s shop, but not at your house, it’s almost certainly your wifi signal.
Can you move the mower closer to the router and see if that helps (bring the router outside or put it in a window and bring the mower over there) and try that.

[Apologies as a flurry of questions ran through my head…]
Make sure you’re not just relying on the app saying it’s not connected*. Check your router to see if it’s connected. Make sure you entered your wireless credentials correctly, make sure there isn’t a firewall issue or that your router isn’t blocking new connections until you confirm them. Is it getting an IP address? Have you tried (and I’m serious) power cycling your router? Try changing the channel on the router. Make sure whichever band the mower uses is turned on. It’s rare, but I’ve run across devices that don’t play nice with mesh networks or networks with the 2.4 and 5 SSIDs being the same. Is that the case for you?

*Did you happen to confirm your phone connects to it while you were at the dealership? If you didn’t maybe see if you can have them connect it to their wifi again and see if your phone can talk to it. If it still doesn’t work, it could be your phone and/or the app.

13

Do you happen to have an extra wifi router lying around? It could be that there’s something weird about the router which isn’t working great with the mower. If you have a 2nd router, you can hook it up to the first router so you have two different wifi networks. Hook the mower up to the 2nd wifi and see if that helps.

If your router has dual frequency support (both 5 and 2.4), switch the mower to use the wifi on the other frequency. The 5g signal doesn’t travel as well through obstructions. The 2.4 signal would probably be better for longer distances.

As a test, you could also turn on hotspot on your phone and see if the mower can connect to the phone’s wifi. If the mower works fine with the hotspot, then it’s probably something about the router causing issues.

I had a router which didn’t seem to like the latest iPhone. When my kid with the latest iPhone came home, the router kept going offline. I got a new router and everything was fine after that. Maybe it’s something weird like that with your router and the mower.

14

My gut feeling is a DHCP issue, possibly with the router. I have tracked down similar issues to find there is something borking the setup.

I would be logging into the router to check on visibility if the mower and that it is sensibly getting a local IP address. You might even go in and hard set the configuration to force a single address. This can fix some problems.

I once found a network behaving like this where an errant device had squatted on the same IP address and never relinquished it. The DHPC server just kept serving out the same address to the other device and nothing worked properly.

15

Hi everyone,
I appreciate all of the advice, but I must admit that I barely understand most of the IT stuff you mentioned. :smile:

I will try moving the router closer to the robot. This might be tricky as it is physically connected to the phone jack and also to the household alarm system, but I’ll give it try.

All the stuff about the router settings is lost on me, but I can call the phone company to see if they can help.

Just to clarify, the connection between the robot and the router seems fine 90 percent of the time and allows me to manage the robot with the app etc. So whatever the problem is, it is not absolute. So I imagine that might rule out some of the suggestions made above?

I note the point that the AirTag cannot fry the wifi card. But could it possibly interfere with the wife connection?

16

You don’t have to move the router if you don’t want to. You can just bring the mower around to the side of the house where the router is. Even better if there’s a window in the room with the router.

In addition to that (and what I was alluding to in my post) is that because 2.4 is slower, but more stable over long distances, many IoT devices not only use 2.4, but don’t even have 5GHz. While that’s generally not a problem, it can be an issue if your router doesn’t have the 2.4GHz band turned on.

Is any of that repeatable? That is, if I ask you to demonstrate what happens when it drops the connection, can you make it do it? For example, does having it go to a certain area of your property cause it to happen? Does it regularly happen after you’ve been using the mower for a certain amount of time (heat buildup/low battery)? etc etc

I doubt it. If airtags caused problems with wifi communication, it would likely be a widely known problem and determining if there’s a nearby airtag would probably be included as one of the first steps in troubleshooting network problems with a lot of unrelated products.

However, until you get this working again, take the airtag out of it. Assuming the problem continues, you’ll have ruled it out as a potential source of the problem and that can be the end of the airtag discussion. OTOH, maybe I’m wrong and that’ll fix the problem. Eitherway, as we remove unnecessary variables, we get closer to the problem.

Is this mower still under warranty or within the dealership’s return window? It might be easier to see if you can exchange it.

I also still think you should try either connecting it to the dealership’s wifi and then seeing if you get the errors on your phone. OTOH, maybe the dealership didn’t experience any problems since, as you mentioned, it works 90% of the time. If you have another phone you can borrow, maybe put the app on that one and see if it changes anything.

17

The base station is already at the closest point to the router. The router is in my living room 12 feet from a large window and another 20 feet across the terrace to the robot. it is almost a clear shot except for the fact that the robot is about 5 feet below the top of the terrace and therefore out of the line of sight. I’ll try moving the router right up to the window, or even out on the terrace.

Kind of. It seems that the robot mows OK for one or two charge cycles in the morning, and then around 12:00 or 1:00 when it goes to charge, after a few minutes it goes offline. I wonder whether something is overheating?

I took the Airtag out yesterday in front of the dealer guy, but the problem remains. So that should rule out connection interference. However the dealer raised the question of whether the Airtag might have already damaged the new wifi card leading to ongoing problems. That’s why I asked about the frying. I think he was just trying to consider all possible causes, but it occurred to me that he might have been making a case for me having voided the warranty. But I’ll fight back if they do that.

It is still under both I imagine. The dealer has been pretty helpful, as has Stihl. But I think the dealer has reached the limit of his knowledge and now we really need to get a Stihl expert to come out. But everyone is on vacation now, so it will be another couple of weeks…

18

One easy thing you could try is to unplug the router, wait a bit, and plug it back in. Maybe the router has something in a bad state and a reboot would reset it.

The charging procedure could be a factor. For instance, the charger may be producing interference which affects the wifi signal and the mower’s wifi gets messed up. You could try changing the orientation and placement of the charging pad so that there’s less interference between the mower and the router. I would guess the best orientation would be where the back or side of the mower is facing the router. If that charging dock (4) is in between the router and the mower, the electronics in it could affect the wifi signal. Also, if the power supply cord has a “brick” in it (6), move it out of the way. The rectangular block in the cord is the transformer and may produce interference.

19

Base station? What’s supposed to be communicating with what? Is the base station something that also needs an internet connection?

Did you happen to have/use this mower in cooler weather? Might be interesting to see if the same thing happens when it’s not the middle of summer.
Next time the connection goes wonky, turn it off for a little while (without charging it) and see if it reconnects when it cools off. It could very well be a heat dissipation issue.

If he was just asking in a ‘thinking out loud’ way, I wouldn’t worry about it too much. If he’s seriously suggesting the airtag may be the problem, I’d find another dealer to work with (and don’t even bring up the airtag).

Does it really require an expert to come out? Can you just exchange it for a new one? It seems like that would be easiest and cheapest for all involved.

You have more patience than I do. I would have made the dealer take it back (or disputed the charge on my credit card) at this point.

I may be wrong here, but as a general warning, be careful in these ‘a few more weeks’ situations. Make sure they’re not trying to run out the clock on the warranty. That’s not entirely unheard of. If it gets to the point that end of the warranty is in the next month or two, you should start pushing for it to get replaced or start working on getting your money back.

20

I’m bumping my own thread to give an update.

So, the saga went on for another month with the misbehaving robot. In addition to the usual offline problem, it started to give me a recurrent ‘battery fault’. I could work around this by restarting the robot manually (without the app). And then a few days later it gave me an ‘internal fault’ error. I could do nothing about that. The robot was dead in the water, so to speak.

I told the dealer that this had gone on enough and I wanted to complete replacement. He agreed without any argument. A few days later they installed a new piece of the same model (the RMI 522 C for those who know the Stihl line). The replacement robot worked for exactly one hour before stopping. And this time the programming screen was completely blank. Flatlined after one hour.

So the dealer took that one back and tested it at their workshop for a couple of weeks. I could see from the app that it was having all sorts of problems at the dealer too. So I called them up again and told them that I think there is either a problem with all 522 Cs, or there is a problem with all of the models with the wireless communication. I also told him that I had been really happy with the previous model (the one that had been stolen – the 422 P). The dealer asked if I would like Stihl to replace the 522 with a 422 without communication, plus a refund for a difference in price.

So I agreed. I have had the 422 now for a week and it is working great. I have no problem in walking out to the garden myself and programming it manually. Seems more personal anyway. Me and my robot pal.

The only downside is that this model does not have GPS, so if anyone should try to steal it again, I won’t be able to track it. So I am trying to build up the courage to put in an AirTag. I know there is no logic to it, but I can’t help but associate the problems I had with the first 522 C model with the AirTag I had installed. Also, the dealer warned me not to attach an Airtag as it might void the warranty….