def char_to_float(c: int, f_min: float = -100., f_max: float = 50.) -> float:
    """Translates char number ``c`` from -128 to 127 to float from ``f_min`` to ``f_max``.
    
    Parameters
    ----------
    ``c`` : int
        value to translate
    ``f_min`` : float, optional
        (default is -100)
    ``f_max`` : float, optional
        (default is 50)
        
    Returns
    -------
    float
    """
    
    f = f_min + (f_max - f_min) * (c + 128.) / 255.
    return f