Page 75:
In Figure 4-26, there should be a ground connection on the line that connects R7 with R8. Please see the following image for the correct figure:

Page 76:
In the sketch for Project 5, the first line of code which reads "#define westButton 7" should instead read "#define westButton 3".

Page 85:
In the formula in the middle of the page, "R3" should instead read "R2".

Page 121:
In the block of code at the top of the page, the line which reads "shiftOut(DATA, CLOCK, MSBFIRST, a);" should instead read "shiftOut(DATA, CLOCK, MSBFIRST, i);"

Page 133:
The bolded segment in the following text should be added to the sketch for program 19:

// Project 19 - Controlling Two Seven-Segment LED Display Modules
// set up the array with the segments for 0 to 9, A to F (from Table 6-2)

#define DATA 6 // connect to pin 14 on the 74HC595
#define LATCH 8 // connect to pin 12 on the 74HC595
#define CLOCK 10 // connect to pin 11 on the 74HC595

void setup()
{
pinMode(LATCH, OUTPUT);
pinMode(CLOCK, OUTPUT);
pinMode(DATA, OUTPUT);
}

int digits[] = {
252, 96, 218, 242, 102, 182, 190, 224, 254, 246, 238, 62, 156, 122, 158, 142};
void displayNumber(int n)
{
int left, right=0;
if (n < 10)
{
digitalWrite(LATCH, LOW);
shiftOut(DATA, CLOCK, LSBFIRST, digits[n]);
shiftOut(DATA, CLOCK, LSBFIRST, 0);
digitalWrite(LATCH, HIGH);
}
else if (n >= 10)
{
right = n % 10; // remainder of dividing the number to display by 10
left = n / 10; // quotient of dividing the number to display by 10
digitalWrite(LATCH, LOW);
shiftOut(DATA, CLOCK, LSBFIRST, digits[right]);
shiftOut(DATA, CLOCK, LSBFIRST, digits[left]);
digitalWrite(LATCH, HIGH);
}
}
void loop()
{
int i;
for ( i = 0 ; i < 100 ; i++ )
{
displayNumber(i);
delay(100);
}
}

Page 153:

In the last line of the code of the sketch for Project 25, "lcd.write(0);" should instead read "lcd.write(byte(0));"

Page 192:
The first line of code on the page which reads "if (attempt[q]==PIN[q])" should instead read "if (attempt[i]==PIN[i])"

Page 260:
In the block of code for Listing 13-1, the line which reads "byte a" should instead read "byte a;"