I have a calculation where the result can vary from -255 to + 255
My mistake. The result is first between -20 to +20 (which is actually an angle in degrees). float is needed because of the multiplication to achieve the angle.

The problem is that the 8051 doesn't actually recognise the negative float numbers when making an if statement like below:

	
        if(value<0)
	{			
		action1
	}
	
	if(value>= 0)
	{
		action2
	}