Using the new PF remote for Technic

[Eric Albrecht]

Hi everyone,

I just got back from Brickfest in Portland and was lucky enough to see the
unveiling of the new 10194 Emerald Night train and the new Power Functions
elements which can be used with it.  

<<http://4.bp.blogspot.com/_MBEVlUMi9kI/Sc6t-Ti-L1I/AAAAAAAABZU/qFXz0cnZqD8/s1600/8879.jpg>>

I'm not a train guy, but I had been anticipating the release of this remote in
the hopes that it would allow better and more precise control of R/C Technic
vehicles and other MOCs.  After most people left one evening I spent a fair
amount of time driving the Emerald Night around the track with the new
controller to figure out how it works and how I might adapt it.  Note that I am
{NOT} an electronics guy and have not read the PF protocol, I was merely testing
it from a practical standpoint.  I've jotted a few of my observations below.
Based on my conclusions, it will not be very useful for controlling vehicles
other than trains.  Feel free to add your own thoughts.

* The control is not infinitely variable.  The control wheels have detents which
  offer a set of discrete power levels.  From what I was able to determine,
  there are 5-7 of them.  While this would work for an R/C vehicle, it is less
  than ideal.

* The signal is not continuous.  When you move the dial, a short duration signal
  seems to be sent out.  This makes sense for trains for a couple of reasons.
  You don't want to have to have the remote on the whole time the train is
  running.  You want "fire and forget".  Also, if the train is out of
  line-of-sight, such as in a tunnel, you wouldn't want it to stop.  So the
  train just keeps going with the last setting until it gets a new signal.  This
  would not work well for R/C vehicles.  First of all, the failure mode of
  getting out of range would be your vehicle driving off into oblivion.  It also
  means that to slow down after driving, you couldn't simply let go of the
  control.  You would have to reverse the direction (or hit the emergency stop).
  This could be partially rectified by setting up a spring return system on the
  controller except for the next point.

* There is no absolute link between control wheel position and speed.  Signals
  seem to all be relative.  In other words, when I turn the wheel 1 click
  clockwise, it sends a +1 signal.  It sends -1 for counter-clockwise.  It does
  not send, for example, "Power Level 5".  This means that if your vehicle is
  out of range when you move the wheel, nothing happens.  It also means that you
  have now lost your center point.  So even if you spring loaded steering
  control to center, one missed IR packet would result in your steering now
  being off.


From what I understand of the PF system, a proper R/C system for vehicles is
possible, but this new system is clearly geared (no pun intended) toward train
control.

The new Li-Po battery, on the other hand, could be quite useful.....

Eric Albrecht

<http://www.ericalbrecht.com/technic Technicopedia>

[Parax]

In lugnet.technic, Eric Albrecht wrote:
> Hi everyone,
>
> I just got back from Brickfest in Portland and was lucky enough to see the
> unveiling of the new 10194 Emerald Night train and the new Power Functions
> elements which can be used with it.
>
....
> * The control is not infinitely variable.  

...
> * The signal is not continuous.  

...
> * There is no absolute link between control wheel position and speed.
>   Signals seem to all be relative.  

....
> The new Li-Po battery, on the other hand, could be quite useful.....
>
> Eric Albrecht
>
> <http://www.ericalbrecht.com/technic Technicopedia>

Thanks for the feedback!

Im not surprised the power level is not continuous, its a digital signal not
analogue! iirc its 2 bytes of data, thats the mode and data for both channels in
combo mode. (There is a toggle setting in one of the modes I suspect that sets
continuous output) I am however surprised at the +1 increment thing using the PF
protocol in combo mode would send a power level... maybe its another mode, I
dont recal them all at present...

Any news on wether the charger is the same as the NXT Battery charger? isn't
that a 10V DC also? (700mA??) Im really tempted by a battery but the price is a
shock!

I'm also wondering (If anyone knows!) if the IR receiver has been fixed, I
believe there was a firmware error in the first batch...(will that affect this
remote?)

Regards

Mike

[Conchas]

>
> Thanks for the feedback!
>
> Im not surprised the power level is not continuous, its a digital signal not
> analogue! iirc its 2 bytes of data, thats the mode and data for both channels
> in combo mode. (There is a toggle setting in one of the modes I suspect that
> sets continuous output) I am however surprised at the +1 increment thing
> using the PF protocol in combo mode would send a power level... maybe its
> another mode, I dont recal them all at present...
>
> Any news on wether the charger is the same as the NXT Battery charger? isn't
> that a 10V DC also? (700mA??) Im really tempted by a battery but the price is
> a shock!
>
> I'm also wondering (If anyone knows!) if the IR receiver has been fixed, I
> believe there was a firmware error in the first batch...(will that affect
> this remote?)
>
> Regards
>
> Mike

Hi Eric,

Thanks for sharing with your findings about the new PF remote with us! I haven't
played with it yet, so was very curious to know about some implementation
details and you gave full light on those.

From your description the remote implements the 'Single Outupt Mode' of the
protocol. This mode implements two other sub-modes, depending on 'M' bit.
So it can be PWM with absolute settings, or 'Clear/Set/Toggle' where remote
actions would increment/decrement the PWM step sent to the motors, lights,
etc... or just clears PWM if you press for instance the Stop button (the red
ones). So the implemented one, should be the second I described.

It has some advantages and disadvantages as you well described. In the end,
because of the implemented sub-mode, it maybe not so useful for TECHNIC
constructions as you wrote. I believe it could have been much better if there
was implemented some button or keystroke sequence that would allow us to select
which sub-mode to use (absolute or incremental). Maybe there is something
hidden. Lets see...

Has Alexandre mentioned today in a comment at TBs, I also believe that main/best
usage for this remote at TECHNIC sets could be to steer treade vehicles.
"differential vehicles should be more precise with this remote, since each
individual track/wheel can have its variable speed, which allows for equally
variable turning radii. Plus, not having to send constantly "move" commands, the
controller's batteries should last longer. "


@Mike,
To my knowledge the IR receiver is still the same, so no fix.
Which however doesn't impact at all with the mode implemented with the new
      remote.
You cna just notice that if programatically trying to use other modes, with an
      NXT and IR Link sensor for instance.

The NXT battery charger, was still the 10V AC version.

[Conchas]

In lugnet.technic, Eric Albrecht wrote:
>
> * The control is not infinitely variable.  The control wheels have detents
>   which offer a set of discrete power levels.  From what I was able to
>   determine, there are 5-7 of them.  While this would work for an R/C
>   vehicle, it is less than ideal.
>

BTW, forgot to mention that the protocol indeed defines 7 PWM steps in each
direction (forward/backward) plus the Float and Break states.