I am trying to find some sort of wifi adapter for Arduino, it needs to be as small as possible (not a shield) and as cheap as possible.

So far I can only seem to find shields that cost about £10+ but I figured that if you can get a replacement wifi adapter for a laptop for next to nothing that I should be able to get a wifi adapter for Arduino much cheaper than this.

It's possible I just don't know what to search for.

  • 1
    The most cost effective solution is likely not to use a literal Arduino, but rather to utilize something else source-compatible which either has wifi built in, or can host a cheap USB wifi dongle. It's not entirely out of the question that such a solution, complete, could cost less than a genuine Arduino UNO - and provide a lot more memory and compute resources to work with. May 30, 2014 at 21:17

4 Answers 4


Some months have passed since my previous answer and now the ESP8266 based WiFi modules are available.

They get connected to your project serially (3.3V) and are controlled in a modem like way using AT commands.

With a pricing of round about $5 they fit the question better than my previous OpenWrt based answer.

For more information about ESP8266 ask your favorite finding machine or list news with tag ESP8266 at Hackaday.

(Old answer from the pre-ESP8266-days:)

I vote for a small router reflashed with OpenWrt like "TP-Link TL-WR703N".

It is like building an own Yùn with an Arduino of your choice...

The WR703N:

It has Ethernet, 150MBit WiFi, USB and if you want to solder, a serial console and 2 GPIO-Pins which can be turned into I2C.

This sure is not a chip- or stamp-sized solution but often cheaper than the alternatives, more powerfull and extendable.

Search the net with your favourite find'o'bot for "arduino wr703n" and you'll find lots of examples...

  • I've seen it somewhere where they use the I2C for direct connection. This would be slower than direct ethernet, but it reduces costs and size without another ethernet chip May 29, 2014 at 13:57
  • The easiest way to connect an Arduino to a WR703N is serial via USB.
    – gone
    May 29, 2014 at 14:01
  • The question was asking for "as small as possible, not a shield" and "less than £10". This isn't it. May 29, 2014 at 18:40
  • @FedericoFissore ... The WR703N in fact is one of the cheapest ways to bring WiFi and Arduino together. It is not my fault if someone dreams to use nonexistent mucht cheaper solutions.
    – gone
    May 29, 2014 at 22:31
  • Ok... now we have the ESP8266 based modules to add WiFI to your projects... ak your favourite finding machine or hackaday.com/tag/esp8266 ...
    – gone
    Oct 26, 2014 at 8:51

The Roving Networks RN-XV WiFly module (found sold at €30) might be a solution. I've never tried it. It supports 802.11b/g.


https://www.forward.com.au/pfod/CheapWifiShield/index.html provides a very inexpensive wifi addon for Arduino

Completed Shield

The WiFi Shield needs just two parts, 4 bits of wire and some soldering equipment. Parts List:-

Adafruit HUZZAH ESP8266 Breakout US$9.95 + shipping
Uno Protoshield US$1.88 + shipping
Total US$11.83 (as of June 2015)
For an even cheaper version ~US7 see https://www.forward.com.au/pfod/CheapWifiShield/ESP2866_01_WiFi_Shield/index.html
Both of these need a US10 USB to TTL cable to program them

After you have installed the pfodESP8266BufferedClient library, open the Arduino IDE and copy this sketch, ESP8266_WifiShield.ino, into the IDE. That provides this setup webpage. Config webpage

  • While that link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. Nov 12, 2020 at 23:08
  • Please disclose your affiliation, you appear to be the author of the site you've linked multiple times.
    – Mast
    Nov 18, 2020 at 17:22
  • Sure I will add a 'my' to future posts.
    – drmpf
    Nov 19, 2020 at 23:15

Texas Instruments CC3000 module 10USD/1000pcs, it does only support connecting to AP, i.e. no AdHoc/AP which is useless for direct using with iPad.

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