Nah, You Don’t Need An Ethernet Module For Your Arduino

[Andy] needed a cheap Internet connection between a data-gathering Arduino and his home server. An Ethernet shield would suffice, but he couldn’t run CAT5 to the Arduino’s location. Wireless shields are hideously expensive, and after looking over the popular Zigbee modules, [Andy] had a few concerns about range and build complexity.

The obvious solution to this problem was getting a cheap WiFi router, flashing OpenWRT firmware on the device, and piping sensor data through the Arduino’s USB port, through the router, and over a WiFi connection to the server.

[Andy] used a TP-Link TL-WR703N wireless ‘travel router’ available on eBay £15 (~$30 USD when we checked). After flashing the router with OpenWRT, [Andy] had a wireless connection from a remote data-collecting Arduino directly to his server.

Attentive Hack a Day readers will note this is the third ‘wireless router + OpenWRT as a dev board’ build this week (first one, second one) . No, we don’t know what’s going on, or why the collective unconscious of makers around the globe decided to latch onto this type of build so suddenly. OpenWRT is available for hundreds of different routers, and anything that keeps disused routers out of the landfill (with the bonus of doing something useful) is alright in our book, so if you have another similar build, send it in and we’ll get around to it sometime.

21 thoughts on “Nah, You Don’t Need An Ethernet Module For Your Arduino

    1. Many reasons: lack of real time, lack of I/Os, level translation unpleasantness, convenience of prototyping the hardware interface with a PC then moving it to the router…

      1. i wonder if one could use one of the free RTOSes available for MIPS such as eCos, RTEMS or RT-Thread on chipsets like the broadcom ones. you *could* have realtime directly on the router.

  1. It seemed like he was hacking together a way of sending the micro serial port data to the wifi connection by using shell scripts. I would recommend an openwrt package ser2net.

  2. “…after looking over the popular Zigbee modules, [Andy] had a few concerns about range and build complexity”

    I don’t get the concerns here. They are pretty easy to setup and configure. Range isn’t a problem if wifi originally met his needs.

  3. OpenWrt might run on many devices, but it’s also good to brick them :(

    Bricked my Linksys E3000 when I tried to flash from dd-wrt.

    Anyway, using a router for a little data mining seems a bit overkill.

  4. Great! I (also?) feel that there is a gap between the way too expensive xbee modules, and cheap 433mhz (or similar) modules. Attaching a whole router to your microcontroller just for comm. isn’t quite elegant, but it is cost efficient though.

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