ESP8266 Community Forum

One of my other hobbies is (air) rifle shooting. I've built a few WiFi enabled targets where a piezo on a ESP8266 attached to a target sends a websockets message to my phone 50m away.

I've had variable success with this. It works perfectly in my garden but is intermittent at the range where I shoot. I shoot within 50m of an O2 cell tower in the middle of nowhere. The cell tower makes me suspicious...

My research tells me that it might be operating at 2.3GHz which is reasonably close to 2.4GHz...

I'm fairly satisfied that the mast is causing my problems but I wondered if anyone here as operated an ESP8266 successfully in close proximity to a cell mast? Or has had similar experiences?

ian wrote:I'm fairly satisfied that the mast is causing my problems but I wondered if anyone here as operated an ESP8266 successfully in close proximity to a cell mast? Or has had similar experiences?

I actually have the opposite problem... on a good day, I might get 2 bars at my house. Many days zero! Great for my WiFi though . I really respond out of curiosity... have you tried changing the channels. If it is in fact the cell tower, it probably blankets all the channels, but you never know till you try.

I'll try forcing the channel selection. This has worked when I've had WiFi congestion problems on other projects.

As an aside, it seems that the channel is arbitrarily assigned when using the 8266 in AP mode. I once looked at optimising the channel selection but it's something I never finished. You could usefully add this feature to your project??

My most recent project prototype doesn't use a ESP device yet. It's a remote camera where an android phone running a hotspot & camera server is positioned close to the target to give shooters a better view. It works perfectly at home but barely works at all at the range. The intention was/is to use a ESP32 Cam as the server.

My next step is to use my phones at 5GHz to see what difference it makes. It's tricky to debug this...

ian wrote:As an aside, it seems that the channel is arbitrarily assigned when using the 8266 in AP mode. I once looked at optimising the channel selection but it's something I never finished. You could usefully add this feature to your project??

I had it exposed as another parameter (on the constructor or begin method - forgot which one) but it tended to cause more confusion for students than being helpful to expose. However, in cases (like you are using) where you only want the SoftAP connection, it would be a good idea. I'll have to think of how to re-incorporate it.

I even had it on my TODO list to do scanning and find the best channel "hole". However, it's way down on the list because...

• I have to weigh the library size increase versus benefit and
• As soon as you connect to any StationAP the ESP8266 switches over to whatever channel the StationAP router uses. I also, internally save that channel change, so when the ESP8266 reboots, I start up the SoftAP (always first) with the changed channel so it saves a little time when it connects to the configured Station AP. That way, it doesn't require the radio to switch. It was a small thing, but it was a noticeable amount of time.

And even though I explained it in documentation... who reads documentation?

... unfortunately, the confusion/frustration factor, "Why is it not on the blankety-blank channel I put in your blank library?"