Page 34 - PDA Robotics Using Your Personal Digital Assistant to Control Your Robot

PDA 01 5/30/03 9:09 AM Page 11
Chapter 1 / Anatomy of a Personal Digital Assistant (PDA)
To provide the optimal balance of high performance and low power
consumption necessary for these devices, the OMAP1510 combines
the TMS320C55x DSP core with a TI-enhanced ARM925 processor.
The ARM architecture is well suited for control-type code, such as the
operating system and user interface. The C55x DSP provides the addi-
tional processing power to handle the compute-intensive operations
such as security, multimedia, and speech. This is a great chip for
PDAs. Figure 1.6 shows the extensively integrated OMAP microchip.
A final example of a system on a chip design is the popular
MC68EZ328 (DragonBall EZ) Integrated Portable System Processor
used in many of the PDAs currently in use. Even though these proces-
sors typically run at a slower clock rate, they are capable of perform-
ing 2.7 MIPS performance at 16.58 MHz processor clock, and 3.25
MIPS performance at 20 MHz processor clock—very impressive for
their size and cost!
The second member of the DragonBall family, the MC68EZ328, inher-
its the display capability of the original DragonBall processor, but fea-
tures a more flexible LCD controller with a streamlined list of periph-
erals placed in a smaller package. This processor is mainly targeted for
portable consumer products, which require fewer peripherals and a
more flexible LCD controller. By providing 3.3 V, fully static operation
in efficient 100 TQFP and 144 MAPBGA packages, the MC68EZ328
delivers cost-effective performance to satisfy the extensive require-
ments of today’s portable consumer market. A number of the Visor
handspring PDAs utilize the Dragonball processors. Figure 1.7 is the
block diagram of the MC68EZ328.

Most PDAs have their small size and expandability in common,
regardless of the processor or operating system. In the near future, we
will likely see enough power in the palm of your hand to make the
desktop computer obsolete! The prices of even the high-end PDAs
have dropped dramatically over the last year, and will likely continue
to do so. There are slews of very low-cost, used PDAs floating around
at auctions, garage sales and in the classified ads. Even a very low-end
PDA running at least Palm OS version 1.1 will be sufficient for this
project. Look around if you don’t have one, and you will likely find a
very good deal on a used PDA.

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