Customer Reviews

Intelligent Sensor Design Using the Microchip dsPIC (Embedded Technology)

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This is an Excellent Book for the dsPIC Enthusiast Interested in Intelligent Sensor Design. The book really does deserve 5 stars. The reason I rated the book 4 stars is that there are a few errors that, once corrected will go a long way to a 5 star rating.

I sometimes get frustrated with an author that makes errors. This book is not riddled with errors like some I've read. In this case, the errors are forgivable as it is obvious that they were made in the effort to get this book to print. The first error has to do with the Nyquist theorem. The author states, "As one can easily see, a problem arises when the highest frequency component in the original signal is greater than twice the sampling frequency, a sample rate known as the Nyquist rate." Opps; the maximum frequency in an analog signal, f1, is often referred to as the `Nyqust frequency'. The minimum sampling rate (2 *f1 samples per second) at which a signal can be recovered is known as the `Nyquist rate'. The `folding frequency', which is one-half the sampling frequency used, is the highest frequency which can be recovered according to the Sampling Theorem (See Lynn and Fuerst, "Introductory to Digital Signal Processing, 2nd ed., p11). Hence, I believe the author meant to say, "As one can easily see, a problem arises when the highest frequency component in the original signal is greater than one-half the sampling frequency, a sample rate known as the Nyquist rate." The other factual error I found was stating that the dsPICDEM Demo board has a temperature sensor with SPI. The board I believe the author is referring to (dsPICDEM 1.1) has a TC1047A which is an analog sensor, not SPI. Neither error is worth rating a book lower, I just wanted to point out two errors that may, at first, puzzle a reader.

So, why is the book excellent? After reading the book, I believe it is fair to say Creed Huddleston is an experienced embedded veteran with a disciplined code style. Creed has mastered the dsPIC and can teach you a lot about using the dsPIC in intelligent sensor designs. That is, if you have an open mind, take the time to read and use the code on included CD, you will learn a lot. The code in the book is very well organized. You will need access to 1) Microchip's C30 GNU C compiler (a free student version is available); 2) the dsPIC Digital filter software (a lite version is available at a modest cost), 3) MPLAB (Free download from Microchip); 4) The dsPICDEM 1.1 demo board (unless you have the time to build your own circuit or adapt the code to another); 5) Time to build an interface circuit to the sensor of your choice. Creed takes you though the rational for intelligent sensors in the early part of the book, though a brief introduction to DSP (this is NOT a DSP tutorial book), though a brief introduction the dsPIC architecture, and finally to sensor interface by example of three projects; a temperature sensor, pressure and load sensors, and flow sensors.

In the latter half of the book, you are introduced to a dsPIC `toolkit', created by the author organized in a framework that you can use in your own projects. The beginning dsPIC developer or an intermediate developer would most likely benefit from learning from the code style, rational behind the code organization, and examples the author demonstrates. The framework is state machine driven using a simplistic approach and is not a UML diagram-based. That is, the style is common sense and low-key to allow the reader to understand the intelligent sensor concept, not software design theory.

The chapters are:
1. What Are Intelligent Sensors, and Why Should I Care about Them?
2. Intuitive Digital Signal Processing
3. Underneath the Hood of the dsPIC DSC
4. Learning to be a Good Communicator
5. A Basic Toolkit for the dsPIC DSC
6. Sensor Application - Temperature Sensor
7. Sensor Application - Pressure and Load Sensors
8. Sensor Application - Flow Sensors
9. Where are We Headed?
10. Appendix A: Software on the Included CD-ROM
11. Appendix B: Initialization of the dsPIC DSC and the System Start-up Code
12. Appendix C: Buffered, Interrupt-driven Serial I/O

This is an introductory text on making sensors "intelligent". It meets that need well.

This book is not a text on DSP. If you need a text book on DSP, get a DSP text book.

This is not a text on PIC microcontrollers. There are several from introductory to advanced in print.

I was looking for good details on the DSP instruction set. The book devotes about 10 pages to the DSP instructions without sufficient depth for you to be able to code your own FIR filters. The Microchip libraries are mentioned but i want to learn the basics. On the plus side is good coverage of the peripherals and interrupts with special attention to the A/D converter setup. There is much in the book that strikes me as padding. Pages of code listing and quite a bit on data communications which is not dspic specific. Basic DSP processing is included for the novice.
All in all a hobbyist level book although a very good one for that level.
For the next edition i want in depth discussion of the DSP core with the address generation and details on coding the basic structure FIR filter in assembly. Put the code examples on the disk not in the text. Less on basic sensors and interfacing and more efficient hardware usage. Note its also very useful for the pic24 series.
If you are beginning the pic24 or DSpic series this is a $70.00 book. But not if you want internal details of the DSP core.