MDB protocol on MSP430

Buyssens Hubert said:

programming MDB protocol

Hmmm, I don't think you are referring to the german senators (Mitglied des Deutschen Bundestages, MDB), no do you mean the message driven beans in java EE. Also, I exclude the Microsoft Access Database and several others.

So what's left is the Multi Drop Bus, a protocol used almost explicitely used for interactions between sales devices. All I know about it is summarized on http://www.vending.org/technical/MDB_3.0.pdf. Honestly, I've never seen it mentioned anywhere, let alone in this forum, so I fear you're on your own.

It looks like a combination of SPI and I2C convcepts. Maybe it can be implemented using MSPs SPI support or even the UART module, but the external hardware is a bit more complicated (open collector bus, galvanic separation etc.). And the software protocol includes slave addressing and polling like I2C, but with separate data lines for each direction. And 9600Bd only. On the bottom line, it seems a bit like an approach of "security through obscurity".