What is the basic requirement to implement RDM?

[ericthegeek]

Just about any 8-bit microcontroller with a UART and a few K-bytes of flash should be sufficient for RDM. Add more flash if you want to program in C instead of assembly, and having >1K-byte of RAM makes things easier. Many RDM products have been built with PICs (16F and 18F series) and 8051 derivatives.

For the most complex products that are likely to need a Full Featured responder, the resources needed to support RDM will be insignificant compared the total computational load on the processor.

[dangeross]

We've just completed as design with DMX, RDM, Closed loop PID control and a rather large ASCII interface for bench testing and calibration during manufacture. The RDM also has an additional 10 manufacturer PID's above the minimum required. All of the code was written in C and used the manufactures library routines to interface to the peripherals, the library does not produce the most effiecent code i.e. function A calls function B calls function C that writes the value passed into function A to a peripheral register.
After looking at the listing output files I remember the code being around 28K including the constant storage space.
If you can stand the slightly higher cost I would suggest a 32-bit micro, we used a ARM Cortex-M3 and if you get to a point where you need to start optimizing code its nice to not have to handle 512 channel, 16-bit pan/tilt, and other data larger than 8-bits with a 8-bit micro. In the past we've used 8051 and Z8 variants and I don't think well ever go back with the new Cortex hardware available from Luminary Micro, ST Micro, and soon Atmel and NXP.