Practical Arduino C

Page 283

#include <stdarg.h>
#define PRETTY_BUFF 80
void setup() {
 Serial.begin(115200);
 pretty("This is the %dth test of %d \n", 5, 10);
}
int pretty(char *str, ...) {
  char buff[PRETTY_BUFF];
  va_list args;
  va_start(args, str);
  vsnprintf(buff, sizeof(buff), str, args);
  int res = Serial.print(buff);
  va_end(args);
  return res;
}

Page 285

#include <stdarg.h>
#define PRETTY_BUFF 80
void setup() {
  // put your setup code here, to run once:
 Serial.begin(115200);
 prettyP(F("This string was %d chars long"), sizeof(test));
}
int prettyP(const __FlashStringHelper *str, ...) {
  char buff[PRETTY_BUFF];
  va_list args;
  va_start(args, str);
  vsnprintf_P(buff, sizeof(buff), (const char *)str, args);
  va_end(args);
  return Serial.print(buff); 
}

Unicode output via the Serial Interface

This secion of the original book has been removed in the second edition.
However the original content has been moved to a blog post along with the relevant code still available to copy and paste.

See Unicode Output from an Arduino