Errata

The example "... if you want to control a 240 V, 40 A contactor with a 24V coil that draws 36 mA, then a relay rated for 100 mA contact current should do fine.? may be confusing because (if I am not confused) it involves a relay driving a relay but this concept or its purpose has not been introduced. Suggest that a more intuitive example be used, e.g. relay driving a light bulb. Further, the subsequent concept "?In this case either a driver IC or a transistor driver as described in the section Controlling Relays With Low-Voltage Logic will be needed.? may compound this confusion: it is ambiguous whether the IC or transistor driver is intended to drive the first relay that drives the second relay or directly drives the second relay instead of the first relay.

Note from the Author or Editor:
Modified by author

In regions that use a 230V AC mains supply, it will be higher than 165V.

Note from the Author or Editor:
Fixed

Suggest adding something about MCUs and other modules that use RS-232 but with TTL level voltages (e.g. Common with Arduino boards and shields) and how this is convenient but prone to smoke if the two are mixed.

Note from the Author or Editor:
Modified by author

Suggest inserting ", including start, stop and parity bits" after "baud, which is the number of bits per second?. This might prevent the reader inferring that "bits per second" means "data bits" and to make the important distinction between baud and data bits per second, preparing them for the next para, which adds detail to that concept.

Note from the Author or Editor:
Modified by author

1. Suggest changing "does not refer to" to "does not necessarily refer to".

2. From the sentences "The DCE devices provide the channel between the endpoints using some type of communications medium. For a system using modems this would typically be a telephone line.? it is not clear whether the DCE is the modem or the telephone in this example, though it reads as if the DCE is the telephone line whereas (my understanding is that) the modem is the DCE.

Note from the Author or Editor:
Modified by author

"?It does not show how the handshake lines would need to be connected.? made this reader wonder why not? Suggest adding a forward reference to the subsequent treatment of this.

Note from the Author or Editor:
Modified by author

(This is an enhancement suggestion, not an error, so if the development process is beyond enhancement suggestions, please ignore!)
Given that outside of the Americas, the ISM 433MHz band is commonly used instead of 902MHz for remote controls etc., it might be helpful to include it in Table 14-19 and perhaps add a column that qualifies the region to which each row applies? For example, when ordering one of those simple ASK/OOK rx/tx modules, a choice of 433/434MHz, and 315MHz are available. A novice reader may appreciate a hint as to why they would choose one over the other. And/or, a reference to somewhere that sets out the regions and the bands (e.g. http://en.wikipedia.org/wiki/ISM_band) could assist.

Note from the Author or Editor:
Excellent suggestion. Author will revise as appropriate.

Using a serial interface (I2C or SPI) reduces the pin count at the expense of conversion speed (as stated in the book) or of communication speed? While a low communication speed will indeed impact the number of samples you can read per second, I believe this should not affect the speed of conversion (as long as separated clocks are use for conversion and communication).

Note from the Author or Editor:
Printed edition, p. 309, 4th paragraph left-hand column:
Replace the word "speed" with "rate" in the third sentence.

Read literally "Heatshrink tubing is perfect for this" seems to recommend using heat shrink tube to make the (re)connections rather than to insulate them after e.g. soldering. Suggest rewording to make the purpose of the heat shrink clear.

Note from the Author or Editor:
qc3 PDF, p. 292, top of rt. col.:
change:
Heatshrink tubing is perfect for this.
to:
finished. Heatshrink tubing is perfect for insulting the reconnected wires (just remember to slide on a section of heatshrink before reconnecting and soldering the wires).

1.The term "saturate" has not been used previously and is not in the Glossary.

2. Suggest changing "close to zero" to "close to zero volts".

Note from the Author or Editor:
qc3 PDF, p. 298, 1st par in sub-sec "SIMPLE ONE-TRANSISTOR BUFFER":
replace:
(i.e., saturate, in this case)
with:
(i.e., saturate, or become fully conducting)

insert "volts" after "zero" at end of same sentence.

Might just be me but I found the wording unclear - I think it is due to the word "once". Would following be correct and clearer? "The voltage potential applied to a sold-state P-N junction that will saturate the junction, resulting in current flow through the junction".

Note from the Author or Editor:
replace "once" with "when"

I assume that "If you buy from overseas, I suggest buying from China" is intended for American readers, otherwise it discourages non-American readers from buying from the USA, which would seem to contradict numerous references to Sparkfun, Adafruit, etc. Perhaps this should be reworded?

Note from the Author or Editor:
p. 485 (QC3 PDF), section "eBay"

Delete sentence:
If you buy items from overseas, I suggest buying from China.

Replace with:
I have also had good results purchasing items from various vendors in China through both eBay and Amazon.