How to print float values using SEGGER RTT

[Jan Lundskov]

Hi, My question is similar to this devzone.nordicsemi.com/.../ but I can't get it to work.

I am using SEGGER_RTT_WriteString and sprintf for debugging, but I am not able to print a float value such as 3.1415. I use the folowing code for printing intergers and it works fine:

uint8_t int_value;

int_value = 129;

char int_str[80];

sprintf(int_str, "Integer value is %d\n", int_value);

SEGGER_RTT_WriteString(0, int_str);

I am then trying to print a float value in the same way, but I have had no success so far. I have tried with "%f", "%0.2f"etc, but the printing result is just nothing or 0.

float float_value;

float_value = 3.1415;

char float_str[80];

sprintf(float_str, "Float value is %f\n", float_value);

SEGGER_RTT_WriteString(0, float_str);

Any suggestions are very much appreciated. Thanks!

[Sunil Shenoy]

@Roger Clark : This method might not yield the right answer if a 0 succeeds the decimal point. Eg: If the number is 3.014, it would print 3.14 while ignoring the 0 after the decimal point.