RDM Hub Implementation

[renatoml01]

Thanks for the attention ericthegeek,

No doubt with the microcontroller will be easier, and I have no problem using them, I have some products that use PICs and could enjoy them on the production line.

So, starting with a microcontroller splitter, I had the following question:

Do I use the microcontroller to "buffer" the message and pass it on?
Or I use the microcontroller just to detect the start communication request and direct the controller communication to responder vice versa.

Trying to explain better.
Thinking about my current 485 transceiver that I use on my DMX splitter, I will leave it like this today and add the microcontroller just controlling the communication direction or I will read the input message with the microcontroller and it passes the message forward.

[ericthegeek]

Both architectures are valid. You can decide which you prefer.

Originally Posted by renatoml01

Do I use the microcontroller to "buffer" the message and pass it on?

Yes, this can work. The microcontroller has to watch all of the ports and determine which is active, then receive bytes and breaks and retransmit them on the other ports.

However, you can't buffer the entire RDM packet. The maximum delay that's allowed for a transparent inline device is 88 microseconds. This means you need to buffer a byte-at-a-time, not an entire packet.

Originally Posted by renatoml01

Or I use the microcontroller just to detect the start communication request and direct the controller communication to responder vice versa.

Yes, this is possible too.

When you build a splitter, you also need to determine whether you want it to be protocol aware. It can receive and parse the packets and try to understand the protocol to make decisions. Or it can just look at the falling and rising edges. It's entirely up to you.