Arduino dtostrf Function

In this tutorial, we will discuss how to use the dtostrf() function to convert a variable of type double into its ASCII representation and store it as a string.

Convert double to ASCII Using dtostrf() Function

The dtostrf() function takes four input parameters.

1. The first is a variable of type double, which we want to convert.
2. The second is a variable of type char used to set the width of the output variable or number of digits.
3. The third is a variable of type char used to set the number of digits after the decimal place.
4. The fourth is a variable of type char to which the conversion will be stored.

For example, see the below code.

double a = 123.123;

char x[8];

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

void loop(){
    dtostrf(a,5,2,x);
    Serial.println(x);
}

In the above code, a is a variable of type double to store the given variable, and x is a variable of type char to store the result of conversion. The result of this conversion will be 123.12.