Rounding Error in 'printf(): Non-Digit ASCII characters generated

[JoWi]

Hi Community,

printf()  (and variants) fail on rounding floats: This is is probably an error in the printf implementation. I tested it with SDK 16.0 on NRF52840.

Format String "%.1f" with argument "0.95" should print "1.0" (or at least "0.9"), but the rsult is "0.:".

It would be nice to have this working.

Best regards,
Jo

// Test function:
case 'z':
	{
	  float fval;
	  fval=atof(input+1);
	  printf("Fval: '%.1f'\n",fval);
	}
	break;

...
// OUTPUT:

>z0.9
Fval: '0.9'

>z0.94
Fval: '0.9'

>z0.95
Fval: '0.:'             <---- ??? Rounding Error (ASCII ':' follows '9')

>z0.96
Fval: '1.0'

>z1.2345
Fval: '1.2'

>z1.25
Fval: '1.2'

[Turbo J]

To my knowledge printf() is implemented in the compiler-dependent C library (libc) and not in the SDK. The SDK ships with the NRF_LOG_FLOAT macros  - these should work correctly.