Possible WiFi network conflict

[MustSeeMelons]

Got myself a situation I can't figure out: I got my main WiFi network coming from an Asus RT-N18U at channel 3, and then I got an ESP8266 01 as my toy network on channel 8. The thing is, when I turn on the ESP, they both disappear, together with most of neighbors networks. Usually their are 7, when both are on I get 1-2. Checked on multiple devices.

Any ideas what could cause this? Maybe plainly the ESP01 is a terrible device?

 

[Kursah]

Sounds like you have conflicting signals or interruption, by many communications standards they are supposed to react that way with interference (give in/fail). I am curious what you've done to configure the ESP and how you're running it. I don't have experience with that particular device though.

But I would imagine it's interfering with more signals and if you turn it on, you lose wireless, turn it off, regain wireless...is clearly the culprit.

What you could do is upgrade your RT-N18U to Merlin, if the stock AsusWRT firmware doesn't support it...and create a secondary guest network on the Asus for your toy network. Or spend more time re-configuring the deployment configuration of the ESP...

Beyond that...you haven't provided enough details to really provide a concrete solution. But if A = OK, and A + B = no wifi, sounds like B is the issue.

 

[MustSeeMelons]

ESP is running my code as an AP, using its standard libraries, not much magic there. This started happening just lately, this is my third ESP01, the two before it died.. Could it be this one is also dying and causing interference? What more details should I share? This is all that I could come up with

I don't have experience with that particular device though.

A very neat device, so small, so cheap, yet can run a web server off of it! Honestly though, doesn't want to run stable, very picky about power. Sometimes runs great, other times just won't start up at all.. The web is full with different ways it should be set-up to function properly, keep this pin high, no keep it low, ugh.

 

[Kursah]

Ya I've read up on it a little more now, seems that they are neat devices. But issue-ridden.

Bummer you have gone through 3 of them thus far though!

Are you able to run a wireless network analysis tool from say your smartphone (android has great options for this.. iPhones...not so much in my experience) or Windows PC (Acrylic provides a great option)? These will be more thorough scanners than Windows Wifi detection. Also, Merlin AsusWRT provides a good wireless network scan utility under Administration if you upgrade to it on your N18U.

Sounds like it's totally the culprit and maybe it's time to find another model/variety of that ESP to start tinkering with..that many failures and issues I'd stop investing in it.

 

[Ferrum Master]

I bet it gets caught in frequency oscillation. Try a different power supply... or you will have to stabilize the one feeding the module, also shield it. Pretty much you will have to do on board montage with additional elements.

Seconds first thing you buy any sorts of electronics gadgets from china - you take it apart and fix it... it includes cold joints and wrong/bad elements.

 

[MustSeeMelons]

I've switched power supplies and it worked better, for a while.. I'm no electrician, but I did add a 470uF cap coming from the power supply, which also worked, for a while..
I did run the WiFi analysis tool on my android, but not when both were on and conflicting - will try that! Also will look into Merlin AsusWRT If all fails I'm throwing away it way.

Have gotten a bit tired of it honestly, so ordered an ESP07, which is shielded and a NodeMCU developer board, maybe these two will work better. If they also will be so moody, guess will have to stick to good old serial for the arduino :/

 

[FR@NK]

Yea using 40mhz channel width on both channels is a great way to bring down your neighbors wifi.

 

[MustSeeMelons]

Yea using 40mhz channel width on both channels is a great way to bring down your neighbors wifi.

Can you be a bit more specific on why is it so?

 

[silentbogo]

The problem with ESP modules, is that they are cheap and poorly engineered for an advertised purpose (or greatly made for other purposes ).
There are millions of variations of Esplora modules, based on Espressif 8266 chipset, and most of them suffer from the following:
1) TX power is way over the reasonable limit on some models(125mW claimed, but definitely "may be inaccurate").
2) due to [1], you have a HUGE transmission range (on ESP01 it is near 350m with PCB antenna, or 500+m with 12dBi external antenna).
3) As already noted, it produces significant interference across the entire 2.4GHz range, so no matter which channel you are on, it will cause some problems on the receiving side.

My advice:
- If you need a short distance low-speed transmission, then use HC-05/HC-06 bluetooth modules.
- If you still want to stick to ESP8266, then reduce its TX power or play with voltages through AT interface. If it has an ext. antenna - remove it.

https://cdn.sparkfun.com/assets/learn_tutorials/4/0/3/4A-ESP8266__AT_Instruction_Set__EN_v0.30.pdf

Can you be a bit more specific on why is it so?

Because at 40MHz channel width you are also blocking nearby channels (e.g. if you use ch.6@40MHz on your router, then most likely neighbor's ch.5 and 7 won't be visible to you).

 

[slozomby]

Because at 40MHz channel width you are also blocking nearby channels (e.g. if you use ch.6@40MHz on your router, then most likely neighbor's ch.5 and 7 won't be visible to you).

a 40 MHz channel 6 will hit channels 2-9 each channel is 5mhz in 2.4ghz . its not so much the 40mhz channel itself that is the problem as it is broadcasting well past your power requirements.

non overlapping 20mhz channels are 1,6,11 everywhere, and 14 in japan ( 14 is offset slightly so it doesn't overlap)
1 and 11 are the "recommend" 40mhz channels. but since there are such limited spectrum in 2.4ghz its not a good idea to use 40mhz. if possible its best to us 5ghz for 40mhz because the channel width is much larger. and there's far more spectrum available there.

 

[MustSeeMelons]

The reason I started looking into ESP modules is that I wanted my Arduino projects to seamlessly connect to PC's through WiFi. Like you put the device in your desk, get out your phone, connect to ESP, tell it to connect to network A, then just launch the PC application and you're ready to go.

ESP would need to handle a lot of simple requests, I even made a stress test for it, which failed at the very start because the sucker doesn't turn on reliably..

Sadly not all PCs have Bluetooth, so that's out of the question.

Oh well, thanks for the input. Not giving up on it yet though

EDIT: Thanks @silentbogo, limiting ESP TX power made it much more stable, seems even rock solid for now!