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ESP8266 - does it really have terrible WiFi range by default??

First time to try this module out and we're disappointed with the range.. as per our testing we can only get max 5m WiFi range line of sight (LOS) to our regular WiFi router (TPlink and other routers we tried)

LOS Distance (Test results based on RSSI):

  • at 6 meters NO CONNECTION
  • at 5 meters -77
  • at 4 meters -70
  • at 1 meter -56
  • at 3 meters -59

We also tried using different WiFi Channel from 1-11
We also tried removing wifi password (no password) and WEP password
We tried also using different modes B G N

NO change ..

Are we doing something wrong here? Or is this module just that bad?

Any solution not requiring hardware change? (because we already bought a lot)

here's our little module enter image description here

Interestingly, I saw these guys test the module and it seemed to work well .. Could we have a fake chip?

https://www.youtube.com/watch?v=7BYdZ_24yg0

We have really hit a stumbling block. hope you guys can help

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  • try to erase the flash with esptool to get rid of old WiFi setting, not compatible with SDK you currently use
    – Juraj
    Aug 27, 2018 at 4:59
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    Do you have a ground plane passing under the antenna? Ideally the antenna should hang over the edge of the board.
    – Majenko
    Aug 27, 2018 at 9:34
  • My ESPs can talk to my inside router from halfway down the block; something is wrong...
    – dandavis
    Aug 27, 2018 at 16:12

1 Answer 1

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The very first thing I notice is that your WiFi antenna is shielded by the PCB. That is the antenna is placed right over the top of the ground plane of the PCB and your range is going to be severely limited.

You will notice on the NodeMCU design below that they have placed a PCB cutout where the antenna is located. In other pictures you can also see that the ground plane does not go past where the antenna starts.

NodeMCU

On other boards the antenna sits proud of the main PCB such as this one from Tronixlabs:

Tronixlabs

If money is tight and new hardware is out, you could try cutting a cutout where the antenna sits using your Dremel (or other rotary tool). If there are any traces underneath the antenna you will need to fix them up with wire worms. Of course it is best to remove the ESP module first.

Alternatively, you could redesign the PCB and send it out for another manufacturing run. I use PCBShopper.com to find the best price for the bare PCBs.

Edit:
Something else you could do is to unsolder the ESP and mount it 90 degrees to the PCB. You would need to solder wires from the base PCB to the terminals of the ESP. This should work and you won't need to cut the base PCB.

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    @BrownChiLD the length of an antenna is tuned so as to transmit/receive at certain frequencies. Adjusting the length will move the frequency away from the WiFi band and result in signal loss. I don't advise doing this at all.
    – sa_leinad
    Aug 28, 2018 at 0:48
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    That may work but it probably won't be as good as the design of the onboard antenna.
    – sa_leinad
    Aug 28, 2018 at 2:15
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    It's not just that both sides of the antenna need to be "exposed", but proximity to other conductors, metal objects, or a ground plane matters. The further you can get the PCB antenna away from any other conductors the better, and your PCB design ideally would have your components on one side of the module and the module's antenna on the other side, much like most of the ESP* dev boards you see. Mar 2, 2021 at 10:30
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    The size and shape of the antenna has been optimised by testing for a certain frequency; soldering more wires to it will change its characteristics and possibly make it worse. It's best to stick with what the engineers have given if possible, and consider an alternative module with an external antenna connector if it's not possible to redesign the PCB or device so the module's antenna sits further away. Mar 2, 2021 at 10:32
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    Datasheet specifies 15mm free on each side of the antenna.
    – EdHayes3
    Feb 9 at 15:47

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