Sending an integer serially in Arduino

integer char byte arduino serial-communication
Sumudu picture Sumudu · Dec 14, 2012 · Viewed 20.1k times · Source

I need to send an integer, say between 0-10000, to Arduino using serial communication. What's the best way of doing that?

I can think of breaking the number into an character array (eg: 500 as '5','0','0') and sending them as a byte stream (yeah, that's ugly). Then reconstruct at the other end. (anything is sent serially as a byte stream, right?)

Isn't there a better way? Somehow, it should be able to assign the value into an int type variable.

(really need to know the same thing about strings too, if possible)

Answer

NiñoScript picture NiñoScript · Dec 17, 2012

If what you're looking for is speed, then instead of sending an ASCII encoded int, you can divide your number into two bytes, here's an example:

uint16_t number = 5703;               // 0001 0110 0100 0111
uint16_t mask   = B11111111;          // 0000 0000 1111 1111
uint8_t first_half   = number >> 8;   // >>>> >>>> 0001 0110
uint8_t sencond_half = number & mask; // ____ ____ 0100 0111
    
Serial.write(first_half);
Serial.write(sencond_half);

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