I am designing a hard real-time data logger. The Uno is a bit marginal in processing speed.
a) Would it be faster if I changed to an ATmega2560?
b) On the datasheet, ATMEGA2560 has 135 instructions; it is 4 instructions more than the ATmega328p.
What are the extra 4 instructions for?
Are they involved in floating point maths?
c) How to select compiler option for fastest code at the expense of bigger code size, longer compilation time, etc.?
The system is:
Receive data from wireless transceiver chip via hardware SPI port.
A good portion of the time is spent on data calculation using floating point maths.
Output processed data on serial port (then to PC via the Arduino board USB to Serial chip).
Code and RAM size is not an issue, Uno has plenty space left.