ESP8266 Community Forum

- Thu May 19, 2016 11:46 am #47666 Using an esp 12E with wider type antenna.
UDP protocol being used. Absolutely stable in my office and around it. Go to an area where there is metal ducting and metal mezzanine upper floor and problems start. Colleagues esp has no issue in the same area.
In this area, the ap will start with signal level around -30dB, but will not allow a connection, then the signal will disappear, maybe re appearing some 10 seconds later, but still no connection allowed.
Thought it was an auto connect issue so that was disabled, but did not help.
Move to a different area and the signal / connection is stable again.
I could understand it if this was common problem area, but it appears not.

If the board layout invited pin rf saturation then this would not relate to the siting.


I'm going to try different channels, and also an esp7 with the crystal antenna, along with trying an external antenna and will eventually solve it, but if anyone has any thoughts on this, I would welcome any suggestions.

Thanks .....

- Tue May 24, 2016 8:54 am #47935 Solved ......
I was using channel 9, which by all accounts is the channel most easily affected by microwave devices 2.45ghz. Plenty of interesting searches revealed that. Tried my phone wifi analyser near (virtually on it) my microwave oven at home , and sure enough channel 9 is affected more so than any other. Thought provoking ......

So, back at work, changed to channel 3 and no problems at all, and considering the amount of metal framework in the area, the range was impressive all over the factory area.
The interference was coming from next doors switch mode fork lift chargers mounted on the adjoining wall, so I couldn't be sure what interference frequencies were being chucked out, but certainly enough to affect channel 9.

Anyway, this demonstrates that this can happen and it is worth checking for sources of interference if no other reason can be found.

- Sun Sep 11, 2016 2:45 pm #54900

Solved ......
I was using channel 9, which by all accounts is the channel most easily affected by microwave devices 2.45ghz. Plenty of interesting searches revealed that. Tried my phone wifi analyser near (virtually on it) my microwave oven at home , and sure enough channel 9 is affected more so than any other. Thought provoking ......

So, back at work, changed to channel 3 and no problems at all, and considering the amount of metal framework in the area, the range was impressive all over the factory area.
The interference was coming from next doors switch mode fork lift chargers mounted on the adjoining wall, so I couldn't be sure what interference frequencies were being chucked out, but certainly enough to affect channel 9.

Anyway, this demonstrates that this can happen and it is worth checking for sources of interference if no other reason can be found.

Interesting. I've noticed "drop offs" on an ESP=12. I thought it was the module, still not sure what it is. If I look at the spectrum with my (Samsung) cell phone wifi analyzer app, I see it fluctuate. If I look with my wife's LG I don't see fluctuations. In both cases I couldn't connect to the AP, but I could log into the station via my router.

Using an ESP-07 the output looked solid on both phones, and I could log into AP, and station. Only difference I saw was that the ESP-12 came up on channel 1, (where my router is) and the ESP-07 came up on 6.

It is my understanding, (and someone please correct me if I'm wrong) that station and ap work on the same channel. If that is the case can I change the channel. I'm using nodemcu firmware in these instances. I see a statement to change station channel, so does this change the AP as well?
Again, thanks to all the great guys that help us learn.