Web platform and Thermal Tweeter wireless tethering

The Thermal Tweeter needs a wired ethernet internet connection to get tweets. At the Open Hardware Summit and Maker Faire we’ll be lucky to have wifi. Likely we’ll need to use a 3G wireless connection. We need a way to bridge the wireless data services to a wired connection.

Today we picked up a cheap router and tested the setup:

  1. A smartphone relays 3G or wifi internet to a netbook over USB
  2. A netbook connected to a router via ethernet shares the internet connection
  3. The web platform connects to the router and pulls tweets from Twitter

More about our setup and prep below the fold.


If we’re lucky wifi will be usable, but a Google Nexus S smartphone is the backup plan. It can share a 3G data connection as a wifi access point, or as a standard USB network adapter. The USB mode relays a wifi connection if available, bonus.

Actually getting a bulk data plan that will work in New York has been a nightmare. The cheapest option is to buy an AT&T prepaid GoPhone ($10) and use the SIM card. 500MB of internet is $25. We can’t get them here, so we tried to order it to the Maker Faire conference hotel. Neither AT&T’s webshop, nor Walmart’s, seem to agree with that idea. We’ve mapped a few shops to try near the hotel instead.

Internet connection sharing

An old netbook running Windows XP is has internet connection sharing enabled. A couple words on ICS:

  • The local connection network adapter becomes a gateway with a fixed address. DHCP is enabled.
  • Our router has a “cable modem hole”. Even though the router got an IP from the sharing PC when connected to this socket, the internet wasn’t available to anything attached to the router.
  • Windows XP will re-enable its silly firewall at the drop of a hat, and never let you know. If things don’t work, always check this first.

We disabled the router’s DHCP server and connected the netbook to a regular socket on the router. That was the magic combination, the Thermal Tweeter prints from wifi and 3G perfectly.

Join the Conversation


  1. couldn’t you use one of those cheap wifi/ethernet bridges for gameing consoles, I think they are around 10-20 doll on Ebay

  2. You could also use a crosscable as no switch is needed. If you want fully in control you could use any linux to accomplish the same with more control over the firewall. Dunno if linux supports the nexus with tethering.

    probly the double nat prohibits proper networking. Our your router does use the same ip range.

    1. vodafone is verizon in the US, and there is no telenor by that name. Ian knows what he is talking about only T-Moble and AT&T use SIMs in the US (major carriers).

      1. I rarely know what I talk about :) In this case teh googlz took me to an international travelers phone/data SIM wiki and it had the best info I could find.

  3. Any of the routers supporting OpenWRT that have a USB socket, coupled with a 3G dongle, probably make a cheaper, simpler, more reliable, quieter solution that draws less power. It would also then support wifi and wired ethernet, were that available….

Leave a comment

Your email address will not be published. Required fields are marked *

Notify me of followup comments via e-mail. You can also subscribe without commenting.