At present there are demonstrations of the petrol and steam versions of the sound unit. Whilst a synthesized engine sound can never compete with recordings of the real thing, nevertheless I think I have captured the 'spirit' of various engine sounds. In all cases the hardware module remains the same and the type of engine sound and it's character are varied by firmware (ie the fitted software) alone.
The hardware is based on PICAXE chips and all units may be built 'as is' using the released software or, the more adventurous of you can experiment by tweaking the values in the code to change the exhaust pulse (or steam hiss) character of each cylinder, the tickover speed, the rev range, the idle time-out period, inhibit or modify the "starter" and the engine run-down to stop etc. The code has been specifically written to make such experimentation easy and has been commented accordingly.
For the purposes of demonstration the petrol engine idle timeout period, normally one minute, has been reduced to a few seconds. Again for the confused amongst you, I am not using the transmitter throttle channel in these videos as it is a ratchet type and rather 'notchy' which spoils my 'smooth as silk' throttle response.
A kit of parts (or made up kits) are available from Technobots. http://www.technobots.co.uk/acatalog/... at a very modest cost. I don't get a penny out of this, I'm merely putting something back into the collective 'pot' from which I've drawn since taking up boat modelling (Autumn 07)