Today LEGO released a new version from the LPF RC Protocol document.
Now in its version 1.20, which can be downloaded from here.
After having analyzed the document, the main changes seem to be:
- Removal of "Single pin continuous mode".
- Removal of "Single pin timeout mode".
- Some commands addition to the "Single output mode". As it seems this has also inherited equivalents to the commands from the first mode above (removed).
Some questions that are now raising in my head, are:
- Why were these modes removed?
- For optimization and reserve space for new modes to come!?
- Is it the "Single pin timeout mode" simply gone?
- Reasoning for the negative logic at some "Single ouptut mode" added commands?
- What have changed besides the protocol?
- Does the RC Receivers will get changed too, getting us a 3rd version of them?
- What about retro-compatibility? I guess the existing receivers will continue to answer to the modes now removed!?
- Any other subtle changes in this new version of the protocol?
...clarification request addressed to TLG.
Having meanwhile studied the document again, I can say the both modes removed ("Single pin continuous" and "Single pin timeout") were incorporated into "Single output mode".
Also and answering to another set of questions above, one can say that the RC Receivers didn't get another change at the time.
It happens this new version of the document describing the LPF RC Protocol was intended to replace the previous one (version 1.10), which was released with errors. Thus the RC Receivers in production by then implement the protocol described in version 1.20, instead of 1.10.
Last Update: 2012.Jun.30 00:30 CET