Mesh/Hardware experiments

This page documents various hardware experiments started 5th of July 2016. Using new types of hardware as home nodes and external antennas and wifi usb sticks.

ESP8266

These aren't full computers, but they're more powerful microcontrollers than Arduinos and cheap (less than $3) and have support 802.11n on 2.4 GHz with all modes (ad-hoc, master, client). Not sure if they support multiple SSIDs at the same time. Power usage is about 0.6 watts when maxing out wifi transmit power.

Omega2 single board computer

• Actually $5 including tax and shipping
• Single 2.4 GHz radio with on-board antenna and u.fl connector
• Has USB and ethernet but no ethernet transformer or plug.
• Power usage: Unknown but probably small.
• Runs OpenWRT
• You can order as many as you want now
• Doesn't ship until November (estimated)

Raspberry PI zero

• Not actually $5 since they can't keep up with demand (more like $15 on ebay)
• No wifi, no ethernet.
• A three-port USB hub with built-in ethernet and micro-usb cable is ~$3 on aliexpress
• Single micro-usb port. You can get $3
• Power usage: Unknown but probably small.
• Runs Debian (well "raspbian")

The Next Thing Co. C.H.I.P. single board "$9 computer"

• Power usage: Unknown but probably small.
• Actually costs $12 in CA with tax and shipping if you order the maximum of 5 units at a time
• Single 2.4 GHz wifi with no external antenna plug (not even u.fl)
• Single USB port
• Runs Debian

Juul likes it. Easy to flash, easy to use and runs debian stably. Its wifi chipset only supports two wifi SSIDs but both master and ad-hoc mode is supported (probably client too but I didn't check). This means that we can have them meshing (ad-hoc) and have client peoplesopen.net but no private SSID.

Nexx WT3020F - Very cheap home node ($12.50)

• Cheap: $12.50 shipped
• Power usage: Only 1 watt!
• Single band 2.4 GHz
• Two PCB trace antennas. No plugs, not even internal.
• Two ethernet interfaces
• One USB plug for host mode USB
• Tiny physical form factor
• USB powered (comes with usb cable but no power adaptor)
• Not AR71xx (ramips mt7620)

Juul (talk) loaded OpenWRT onto one of these and started a compile of sudowrt for this chipset. OpenWRT seems to work fine.

The firmware was flashed via the existing web UI which is available on 192.168.8.1 with user/pass admin/admin.

RT5572N - Dual-band single radio USB wifi adapter ($6)

• Two PCB trace radios
• Two u.fl connectors
• Does either 2.4 GHz or 5 GHz

Juul (talk) tested this on a Nexx WT3020F and it seems to work quite well. Here's how to install the driver:

opkg update  
opkg install kmod-rt2800-lib kmod-rt2800-usb kmod-rt2x00-lib kmod-rt2x00-usb  

Seems to support an arbitrary number of ad-hoc/client/master mode wifi interfaces (tested up to 8).