CODEWITHSUNDEEP
c++arduino
Marco Pizarro-Silva
Marco Pizarro-Silva

Reputation: 23

Atoi() function not working Arduino

The Arduino atoi() function is not working as expected. The original is 656649, but when converted to a string, it prints 1289. What could be happening? Thanks!

void setup() {
  Serial.begin(9600);
}

void loop() {
  String BT1 = "656649"
  Serial.print(" String BT1: ");
  Serial.print(BT1); // OUTPUT: 656649
  char charBuf[50];
  BT1.toCharArray(charBuf, 50) ;
  Serial.print("Char buff: "); // OUTPUT: 656649
  Serial.print(charBuf);
  intBT1 = atoi(charBuf);
  Serial.print(" intBT1: "); //OUTPUT: 1289
  Serial.print(intBT1);
}

Upvotes: 2

Views: 7223

Answers (1)

TomServo
TomServo

Reputation: 7409

The Arduino int and 'unsigned int types are 16-bit values, too small to hold the number you used. You need a long or unsigned long type to hold that value; these are 32 bits long in the ATmega (Arduino) architecture.

Many programming problems with the Arduino stem from these different sizes -- as most personal computer are 64-bit these days, it's easy to forget that the microcontrollers at the heart of the Arduino family are Harvard architecture 8-bit machines with 8-bit registers.

Upvotes: 2

Related Questions