Testing and Building with the New gumstix SBCs, Part 1

Vendor:gumstix

URL: www.gumstix.com and www.gumstix.org/tikiwiki

Prices: connex 400g - $139 US; etherstix - $49 US; waysmall - $20 US

At the time of my first review of the original gumstix product, the gumstix waysmall 200X (ws200x), it contained the versions of what the company since has renamed the Basix FFMC. One version was available with Bluetooth connectivity and one without. The gumstix company prefers to refer to its modules as Full Function Miniature Computers (FFMC), principally because of the move toward the mother/daughter card concept. In the first review, I explored the strengths and weaknesses of these products. Here, I revisit the issues discussed in the first review and provide a status update.

For this review, I received a power supply, the new connex 400g FFMC and several daughter boards. Because so many new boards are available and there is so much material to cover dealing with this, this review is divided into a couple of parts. This time we discuss the gumstix connex 400g, the etherstix daughterboard and finally the waysmall daughterboard.

Figure 1. The connex 400g

Figure 2. The etherstix Daughterboard

Figure 3. The waysmall Daughterboard

During the course of writing the original review, I identified three primary concerns with the gumstix products:

The concern about I/O lines primarily was directed at the waysmall configuration of the gumstix FFMC. In many ways, the waysmall is an excellent development platform, as it is better protected from the environment than is the naked gumstix FFMC. However, the waysmall did not allow for any access to the I/O lines. The only real solution to this concern was a substantial hardware change. On the gumstix basix FFMC, the difficulty lies in the fact that all I/O access is handled through the 60-pin Hirose I/O header. Although the Hirose connector was a step forward in the stability of the physical connection, actual access to the I/O was diminished somewhat. The Hirose essentially required the user to design a daughterboard and surface-mount connections to the female Hirose on the motherboard. Consequently, this becomes a costly investment for a hobbyist who simply wants to experiment with the gumstix FFMC.

Although gumstix has not chosen to make this change on the waysmall, the company has provided a solution to the I/O access problem by releasing a breakout daughterboard, which I will discuss in a later article. All in all, the I/O access deficiency has been resolved, because the gumstix FFMC principally is an embedded tool. Consequently, as long as a cost-effective I/O access option is available--meaning no roll-your-own breakout boards--the need is satisfied.

In terms of the documentation, the principle criticism essentially was the lack of documentation and the draft nature of what was available. The original manual was a rough introductory document. Now, however, the principle documentation is available on-line. It provides a lot of useful tools to generate what essentially are custom manuals. In addition to the manuals, forums, FAQs and many other resources are available through the wiki. Some issues still exist in terms of the generated manuals skipping some key point, such as schematics. Overall, though, it is an excellent way to get the specific information you require.

The rapid development of the gumstix line is both a strength and weakness of the company's products. To its credit, the company appears to be maintaining backward compatibility wherever possible. One must keep in mind, however, that if you are designing a particular product line, the current model may change quickly. For example, look for the transition to a newer XScale PXA processor to happen sometime in 2005.

With regards to the fragile Bluetooth antenna connector, this is the only issue yet to be addressed in full. At the time of my first review, there was some discussion with gumstix about the fragility of the Bluetooth antenna. The company acknowledged the problem and was considering what options were available. An integrated antenna on the gumstix motherboard would take up a great deal of precious real estate, but this option is under consideration if it can be integrated with a Wi-Fi antenna.