Recommended external antenna for D1 Mini Pro?



  • I'm going to be working on the project where I have my mini pro in an enclosure (just a plastic one) and I'm not yet sure of the distance and obstacles between it and the closest wireless access point. I'd like to pop a hole in the side of the enclosure and run an antenna out. I understand the antenna connection to the Mini Pro is an IPEX connector and a jumper resistor needs to be moved, however I've recall some debate (on the old forum) on whether any external antennas showed a real improvement over the ceramic.

    I'd like to hear the current consensus on that (if it exists) and any antenna recommendations. Thanks!



  • @structure7

    I bought and am using these antennas and cables with my D1 Mini Pros:

    There were some early reports that the external antennas didn't work well but it turned out that a few users hadn't moved the zero-ohm resistor to activate the external antenna connection. The consensus now is that using the Pro with an external antenna delivers the best performance by a good margin. I don't remember the exact RSSI improvement but I think it was around 8-10db.



  • I've tested with 5-7 dbi antennas and they really do considerably improve results relative to the ceramic antenna. The ceramic antenna is also worse than the PCB antenna of the D1 mini (non pro), at least in the situations I've tested.

    The debate you recall was mostly because some tests did not move the jumper resistor.

    I managed ~400 meter range in 802.11b mode with no line-of-sight (down the hill along a road). That was using this 7dbi antenna. And I believe the other end was a regular d1 mini acting as the host.



  • Thanks for the replies... I can see how people see that antenna connector but miss the small open bridge! I shall enjoy fumbling through my first pass at SMD soldering. Thanks too for the links.



  • @Roo-ster said in Recommended external antenna for D1 Mini Pro?:

    @structure7

    I bought and am using these antennas and cables with my D1 Mini Pros:

    There were some early reports that the external antennas didn't work well but it turned out that a few users hadn't moved the zero-ohm resistor to activate the external antenna connection. The consensus now is that using the Pro with an external antenna delivers the best performance by a good margin. I don't remember the exact RSSI improvement but I think it was around 8-10db.

    @Roo-ster or @deshipu ;
    I just completed a project. The Wemos D1-Mini installed in the aluminum box does not connect to the WiFi. So I was thinking on using the Pro version since it has an antenna connection. I have the D1miniPro & antenna sitting in my AliExpress cart waiting for a reply before I make the purchase. I'm going to ask the dumb question because I honestly don't know... Shielded cable? We're not talking about the plastic coating that comes on wires but some other sheilding? One last item. Can you send me a link giving good directions on the removal of the resistor? Assuming I still have to remove some resistor prior to clipping on the external antenna.

    THANKS. Nick



  • Yes, by shielded cable I meant a cable with a metal sleeve around it, usually woven from wires, for example like the USB, audio or antenna cables.

    The resistor you need to move is that black part with white "0" written on it between the antenna socket and the ceramic antenna:
    alt text

    You need to desolder it (use a safety blade to heat both ends of it at once) and then re-solder it horizontally, to the pad next to it. If you damage it during desoldering, you can replace it with just a short piece of wire.

    However, I'm afraid that if the antenna is going to be close to the source of noise, this will not help, as you will still get all the noise through the antenna.



  • @marine_hm

    Here's a video from youtube:

    It's really not difficult. Just be careful that the 0 ohm jumper doesn't fly off and get lost. (I dropped one and had to solder on a tiny wire).



  • My soldering skills have greatly improved since last year when I started teaching myself arduino/C. No experience with SMD soldering. You think a paperclip unfolded and looped back like tweezers on each and of the resistor. then bridge the iron across both ends would work? Going to give it a try when it gets here. I'll figure it out. Thanks for the video link. Looks pretty straight forward... I'll be back when it arrives in the mail.



  • @marine_hm

    A pair of metal tweezers is cheap and useful. If they have 'dollar stores' where you are, look there.



  • My chip looks slightly different than the one in the video. I may only have one legitimate shot at this, I want to get it right. I'm swinging the top right of 0 ohm resistor, moving it left as the green highlighted?
    0_1499772413431_AntennaMod.JPG



  • @marine_hm

    Correct.



  • Looks like I have success. Just have to be patient, wait for the antenna from AliExpress.. What I found while doing it, the tweezers acted as a heat-sink. So, I had to turn up the heat some to compensate for that.
    0_1499944648651_AntennaMod.jpg



  • I am myself considering to get this 7dbi antenna but I have seen that the connector is not the same, being sma in the antenna and mmcx in the wemos pro mini. Have you found the same antenna but with the mmcx connector, or have you used a sma to mmcx adapter? a friend of mine has recommended me to use no adapters as possible...

    as a matter of fact, he sais that it would be better perhaps to have a 3dbi antenna with short cable and no adapters than a 7dbi antenna with adapters and a long cable.

    whats your opinion on that?

    thanks!



  • The antenna came in, clipped it to my Wemos Pro and then connected it all up. Everything works perfectly! Thank you all so much.



  • I am comparing the RSSI using a d1 mini and a d1 pro mini + external antenna. The improvement with the pro mini + antenna is not as significant as I expected. 1 to 3 dBm in the best of the cases



  • Correct me if I'm wrong, but since decibels are logarithmic, 3dB is increase in power by roughly two times? How is that small?



  • you are not wrong. it is logaritmic.

    I am no expert, and it is true that 3dBm is the double, but 1dBm is not. I was expecting to get a bit more with an external antenna. But as I said, I do not know much about this, so my expectations can easily be to high.


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