Article Index

Page 3 of 16

Page 48

void setup() {
  pinMode(2, OUTPUT);
}

void loop() {
  digitalWrite(2, HIGH);
  digitalWrite(2, LOW);
}
 

Page 49

void setup() {
  pinMode(2, OUTPUT);
}
volatile int waste;
void loop() {
  digitalWrite(2, HIGH);
  for(waste=0;waste<6;waste++);
  digitalWrite(2, LOW);
}
 

Page 50

void setup() {
  pinMode(2, OUTPUT);
}
void loop() {
  digitalWrite(2, HIGH);
  delayMicroseconds(1);
  digitalWrite(2, LOW);
  delayMicroseconds(1);
}
 
 

Page 50

void setup() {
  pinMode(2, OUTPUT);
}
volatile int i = 0;
int n;
void loop() {
  for (n = 1; n < 11; n++) {
    digitalWrite(2, HIGH);
    for (i = 0; i < n; i++) {}
    digitalWrite(2, LOW);
    for (i = 0; i < n; i++) {}
  }
}
 

Page 52

unsigned long tick_us(unsigned long offset) {
  return micros() + offset;
}

void delay_until(unsigned long t) {
  do {
  } while (t > micros());
}

void setup() {
  pinMode(2, OUTPUT);
}

volatile int i = 0;
int n = 2;
unsigned long width = 1000;
unsigned long t;

void loop() {
  t = tick_us(width);
  digitalWrite(2, HIGH);
  for (i = 0; i < n; i++) {}
  delay_until(t);
  t = tick_us(width);
  digitalWrite(2, LOW);
  for (i = 0; i < n; i++) {}
  delay_until(t);
}
 

Page 54

void setup() {
  pinMode(2, OUTPUT);
  pinMode(4, OUTPUT);
}

void loop() {
  digitalWrite(2, HIGH);
  digitalWrite(4, LOW);
  digitalWrite(2, LOW);
  digitalWrite(4, HIGH);
}

Page 56

void gpio_set(int32_t value, int32_t mask) {
  int32_t *OutAdd = (int32_t *)GPIO_OUT_REG;
  *OutAdd = (*OutAdd & ~mask) | (value & mask);
}

void setup() {
  pinMode(2, OUTPUT);
  pinMode(4, OUTPUT);
}
volatile int i = 0;
int32_t mask = 1 << 2 | 1 << 4;
int32_t value1 = 0 << 2 | 1 << 4;
int32_t value2 = 1 << 2 | 0 << 4;
void loop() {
  gpio_set(value1, mask);
  for (i = 0; i < 5; i++) {}
  gpio_set(value2, mask);
}