Fixed Point Library Creation

Fixed Point Library Creation
Date Sun 31 January 2016
By Jason Jones
Category fixed-point-math
Tags fixed-point-math c fixed-point math

So I have been doing some reading and looking around recently regarding Q1.15 math and embedded C and I am surprised at the lack of libraries out there. I remember implementing some fixed-point math in my motor control days, but I would have thought that there would be an easy-to-install and easy-to-use library out there.

There has definitely been some work done in the Q16.16 space (see libfixmath), and the gcc toolchain has begun to support the _Fract type - with all of its subtypes - but it doesn't seem quite uniform as yet, particularly across manufacturers.

As a result, I decided to create a github repository with my small contributions to Q1.15 math. It isn't mature, by any means, but the end goal would be to have a library that works well with a range of 8-bit and 16-bit processors.

I have implemented - and tested! - 90% of the functions that I find most useful in embedded applications. I have also added assembly optimizations for the Microchip 16-bit line, but I could use some help porting to other processors. Any help would be appreciated!

Want to learn how fixed-point math works?