Jan 312017
 
Wemos D1 mini pro - how to move the zero ohm resistor to use an external antenna

In my previous blog post I showed how I used several Wemos D1 mini to make a network of wireless temperature sensors around RasPiTV HQ. These litle boards are based on the ESP8266 microcontroller with built-in WiFi.

There is a Pro version available too. One of its main benefits is that you can attach an external WiFi antenna for greater range. This is an optional feature, and it does require some delicate surgery to reroute the antenna signal from the built-in ceramic antenna, to the external socket. It’s not especially difficult once you know what you’re doing, but it is very small if you’ve not worked at this size before.

Zero-Ohm link on Wemos D1 mini pro

Zero-Ohm link on Wemos D1 mini pro

There is a small surface mount (0603) Zero Ohm resistor (sometimes called a link) which needs to be rotated to enable this change. It is a challenging procedure simply because of the size of the component. I messed it up first time, but treated that as a rehearsal. This is the performance, and it went quite well. I caught the whole thing on video and this is a video post. Enjoy!

  6 Responses to “How to use external antenna on Wemos D1 mini pro – surface mount rework video”

  1. Very interesting video – well done.
    Can I suggest that you fix the board to the table top with some blu tack to hold it really still when attempting such delicate work. I find it really useful when working on difficult soldering tasks. The blu tack rolls off without leaving a trace.
    Which heat gun do you use?

  2. The zoomed-in video with the giant cocktail-stick reminded me of https://www.youtube.com/watch?v=TV7sbaffuNo ;-D (watch the whole thing, and you’ll see what I mean)

    Do you not have a stand-mount magnifying glass Alex? I bought one with a built-in LED light from Rapid Electronics at a CamJam a while back.

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