Over at CNET, MOTO Development Group president Gregor Berkowitz has a new column that looks under the hood of Motorola’s Droid smartphone to evaluate what made the product successful — and how it could be improved.

This much is clear: Motorola positioned the Droid to be the anti-iPhone. While the iPhone is sleek and rounded, the Droid is square and angular. Where the iPhone seems lightweight and delicate, the Droid feels heavy and rugged… so much so that Gregor calls it the “Hummer of smartphones.”

The obstacles Motorola faced in bringing the Droid to market and re-establishing its own relevance as a maker of cutting-edge handsets are more than skin deep. To get a running start in the fast-changing smartphone business, Motorola embraced Google’s Android operating system instead of building one of its own. Yet that move created challenges of its own, as Motorola was then forced to adapt its handset hardware to the idiosyncracies of a third-party OS.

Tuning a piece of hardware to a piece of software is a laborious and time-consuming task, and upon close inspection, the Droid still bears some scars from the process — most likely because Motorola was in a hurry to rush the product to market. To learn about some of the ways in which this becomes most apparent, read Gregor’s column.

The success of the iPhone has triggered the adoption of touchscreen systems in a wide range of mobile devices, and a bevy of new gadgets equipped with capacitive sensing technology have now hit the market.  MOTO has years of experience developing products that use capacitive touch, and we’ve had the opportunity to test many of the latest devices. Our conclusion: All touchscreens are not created equal.

It takes finesse to create a touchscreen system that’s pleasant to use, because touchscreens require seamless integration between hardware components, software algorithms, and user-interface design. If a manufacturer cuts corners or flubs any of the critical elements, the user’s experience with a touchscreen product is likely to suffer.

Simple and True

Although we usually use sophisticated tools to test touch screen accuracy, MOTO has also developed a simple technique anyone can use to evaluate the resolution and accuracy of a touchscreen device. All you need is a basic drawing program (download one if necessary), a steady hand, and a few straight lines drawn very slowly on the screen.

This video shows what happened when we recently took several touchscreen systems out for a test drive:

The Virtue of Slow

Why do you need to draw slowly?  On a good touchscreen, users can draw clean straight lines, even while going very slowly, so the graphics that appear on screen accurately represent what was physically drawn.

On inferior touchscreens, it’s basically impossible to draw straight lines. Instead, the lines look jagged or zig-zag, no matter how slowly you go, because the sensor size is too big, the touch-sampling rate is too low, and/or the algorithms that convert gestures into images are too non-linear to faithfully represent user inputs.

Pressure Matters

Also, even on a single device, the amount of pressure and the part of the finger you use on the screen has an impact on how well it senses. A good touchscreen device will produce linear output regardless of whether you’re using the full pad of your finger, or just the dry corner of your cuticle.  When comparing devices, make sure to use even pressure across all of them.

If you want to show the most extreme case, draw very lightly with the corner of your finger. The artifacts will increase significantly, showing which device is really the best with a weak signal. This is important because quick keyboard use and light flicks on the screen really push the limits of the touch panel’s ability to sense.

Here you can see the results of our test:

Edge Performance

Take careful note of the performance at the edges of the screen. The performance at the edge is challenging to tune, and separate from the basic “waviness” test. The iPhone tracks all curve very strongly as you approach the edge of the screen, despite a straight finger trajectory. This is especially obvious at the bottom, where the iPhone has a sensitivity problem.

The Droid Eris [Nexus One] is actually the clear winner for edge performance — the signal tracks right off the edge of the screen very consistently.

[edit] As of time of first writing, we hadn’t tested the Nexus One.  It does slightly better than the Eris.  In fact, they both use the same touch controller IC.

A Quest for High Signal-to-Noise Ratio

To create a superior touchscreen experience, it’s essential to develop a touchscreen sensor that has the highest possible signal-to-noise ratio, or SNR. When a manufacturer gets it right, the device tracks touch inputs almost as if they were connected to physical objects in the real world. Get it wrong and consumers end up with inferior touchscreen systems that are inaccurate, insensitive, and absolutely infuriating to use for typing.

Key drivers of SNR include:

• Conductive sensor material
• Substrate material
• Substrate thickness
• Distance from display (the biggest noise source)
• Sensing waveform
• Sensor pattern
• Sensor pitch
• Analog sensing circuitry
• Sample rate

Touchscreens are a catalyst for innovation and a powerful way for device manufacturers to differentiate their products in an intensely competitive marketplace. But as our demonstration shows, there’s a right way and a wrong way to deploy the technology. MOTO has worked with capacitive touch interfaces for more than 15 years, and here are some essential dos and don’ts for anyone entering the field:

• Don’t skimp on materials. With touchscreen hardware, manufacturers get what they pay for — and consumers will notice the difference.
• Allow ample time to develop your algorithms. Don’t treat touchscreen algorithms as an element of component sourcing; for best results, create a distinct touch development track under your own roof to make sure your products are both responsive and accurate.
• Closely integrate touchscreen hardware, software, and user interaction development, and do so as early as possible in the product development process. Never treat them as separate tasks.