Issue 132 July 2001
Liquid Crystal Delight

Start • Working Glass Hero •Quarter Horse •Software To Boot •Widge Warrior •Highway Star •Beta Site •Take It Easy •Sources & PDF

SOFTWARE TO BOOT
It’s great that Amulet offers an easy integration (i.e., connects to anything with a UART) solution for mid-range display apps. However, hooking up the hardware is only part (arguably, the easiest) of the story. No matter whose chip you use, there’s still the small matter of software to make it do something useful. It isn’t hard to cobble together some low-level drivers such as BitBLT (bit block transfer) or a line algorithm, but it’s a long journey from these primitives to a pleasing user interface. Worse, the more cycles your host controller has to spend babysitting the display, the fewer cycles it has available to handle the embedded application.

Wouldn’t it be nice to be able to take advantage of powerful desktop software tools to craft your user interface, but without having to burden your application with the full baggage of an embedded PC? Well, hang on to your logic probe, folks, because that’s just what Easy GUI purports to do. The trick can be described in four letters, HTML. Here’s how it works.

Start with your favorite web page editor and craft your user interface, including touchscreen hyperlinks, right on screen. Of course, you can evaluate, share, or otherwise fool around with your user interface design using a standard web browser. When you’ve got it just right, run the desktop HTML through Amulet’s HTML compiler.
The HTML compiler munches on your pages and outputs a condensed version Amulet Technologies calls uHTML. The uHTML gets downloaded to the serial EEPROM on the module where it’s interpreted by the Amulet chip at runtime using a built-in uHTML browser.