I'm thinking about making a "hardware" little drum machine / sequencer on an RTOS running some Linux RTOS..

Anybody got any suggestions if "Pure data" is a good idea to use and which RTOS that would fit or if there is better stuff to use? All inspiration / suggestions / inspiration welcome.

The machine would perhaps look like a "launchpad" kind of, but with some extra knobs with a 3.5 mm output plug for earphones and a usb port (or perhaps transfering data via the 3.5 mm plug ))) with some imaginary complex numbers for transfering data I want to have some flexibility in creating the synths etc but i dont want unnecessary extra work

Just a hobby project / idea.