My customer wants us to write direct C code to implement the ATO algorithms (without drivers provided by NXP) as described in the application note AN3943, using Kinetis-V MCUs. We have to develop code using floating point and then followed by fixed point and deliver to the customer. For the first version we were trying to understand Eq-10 and 11 (Page 6). We are not very sure where does it come from and how the term pi appears in the equation? And Secondly why was forward euler chosen over tustin's approach. Can we directly code the equation (for floating point) and get desirable results?