Roger Meike's Blog: Sun Labs and Beyond

Open Source hardware is a slightly more complex concept than open source hardware. It still takes more resources to develop hardware than software, but generally open source hardware can significantly reduce the barrier to entry. The subtly comes into play in the varying degrees of openness in hardware. You can release schematics which add to the understanding of a design and encourage new designs. You can also release layouts and bill of materials which enables others to more easily build exactly the same board as well as encourage new designs. With Project Sun SPOT, we have already released eBones, an open source project to encourage new application boards for the Sun SPOT. Now we are releasing several new boards which significantly add to the functionality of the Sun SPOT. There are a grand total of 6 boards included here, and we are including everything - schematics, layout and bill of materials; it's everything you need to build these boards.

The Sun SPOT is designed for flexibility. One of the ways we achieve this is by dividing the system into physical components. The battery provides power. The Processor Board does the heavy lifting. This is where basic functions like Java run and where the radio lives. The application specific hardware lives on the sensor board (which I often call the application board). It is what provides the basic sensing and effecting connections to the outside world. It is these interchangeable application boards that are providing as open source. Lets take a look at what we are making available:

eDemoBoard - We ship the Sun SPOT with the eDemoBoard which is one of the boards that we making available as open source. It includes a light sensor, temperature sensor, 3D accelerometer, 8 24-bit LEDs, two push buttons, 6 analog inputs, 5 digital I/O lines and 4 digital outputs. We consider it the kitchen sink of application boards. The eDEMO has comprehensive Java classes, preinstalled firmware and many demonstration programs that use this board. This 1.9" x 1.5" board fits inside the plastic case.

eFlash - eFlash is a stackable add-on board for the Sun SPOT project and is used for data logging. This board uses two of the industry standard MiniSD flash cards. The PC board is 1.9" x 1.5" and fits inside the plastic case. The MiniSD connector on top uses the ARM9's 4bit high speed SD/MMC interface while the bottom MiniSD connector uses the standard SPI connector. The board contains the identification serial Flash memory, 2 MiniSD card connectors, and decode logic.

eSerial - eSerial is a stackable add-on board for the Sun SPOT project providing a single RS232 connection. The PC board is 1.9" x 1.5" and fits inside the plastic case. The board requires an extension flat ribbon cable to the appropriate DB9 or DB25 connector. The level shifted RS232 connects to UART0 of the ARM9. It contains the identification serial Flash memory, RS232 level shift circuit, and activity LEDs.

eProto - eProto is a stackable add-on board for the Sun SPOT project for prototyping hardware interfaces to the SunSPOT.

The PC board is 1.9" x 1.5" and fits inside the plastic case. It contains the identification serial Flash memory, SPI address decode, 3V to 5V DC/DC converter and a sea of 0.1" pads for prototyping. The pads closest to the connectors are wired to the interboard connector and SPI chip selects.

eProtoMega - eProtomega is a stackable add-on board for the Sun SPOT project for prototyping hardware interfaces.

This board is similar to the eProto board with the addition of a Atmega88 processor.
The PC board is 1.9" x 1.5" and fits inside the plastic case. It contains the Atmega88, identification serial Flash memory, SPI address decode, 3V to 5V DC/DC converter and a sea of 0.1" pads for prototyping.

eUSBHost - There is no photo of this one because we haven't built it yet. In fact there is a significant software effort required to support it. eUSBHost is an add-on board for the Sun SPOT project for adding USB hostThe PC board is 1.9" x 1.5" and fits inside the plastic case. It contains the identification serial Flash memory, SPI address decode, optional 3V to 5V DC/DC converter and USB Type A host connector (vertical or horizontal). This unit has is design only, it has not been prototyped.
Open Source! Hardware designers rejoice! Go forth and have fun!