Ben-WPAN Overview

A first run of atben and atusb boards has been produced by Tuxbrain S.L. and further revisions of atusb have been produced and are available for sale from sysmocom.

atben (for the Ben NanoNote) atusb (Full-Speed USB)

Hardware

Both boards transmit with a maximum power of 2 mW (+3 dBm) over a distance of up to about 10 m in a typical indoors environment.

The standard data rate of IEEE 802.15.4 is 250 kbps. The transceiver supports non-standard rates of up to 2 Mbps, with a reduced range.

Compatibility

atben plugs into the Ben's 8:10 card slot. Note that it is not an SDIO card.

atusb is designed for USB 2.0 Full-Speed and has an USB A connector. The host needs suitable drivers for the board.

Software

To make use of the boards while working on IPv6, we have developed a quick and dirty tunnelling mechanism for IPv4. A video demonstrating its use can be seen here.

atben has no local "intelligence" and its SPI interface is bit-banged directly by the Ben.

atusb uses an Atmel ATmega32U2 microcontroller to interface between USB and SPI with a homebrewn protocol on top of USB.

The firmware includes a boot loader allowing easy firmware updates in the field with the DFU protocol.

This boot loader occupies a fixed 4 kB of the 32 kB of Flash memory in atusb. The "application" currently uses another 6 kB. Developers wishing to extend or replace the firmware thus have between 22 and 28 kB available for experiments.

While not an immediate project goal, it may be possible to write firmware for atusb that turns it into a transparent gateway for legacy operating systems and protocols.

Status and resources

Further reading