Lego reveals Power Functions IR Protocol

[Siegfried]

I found this via a press release on brickjournal. Reading though the data makes me think that the current protocol will live on in the 08/09 sets, as will the reciever. However it seems the remote will not as it supports only the on/off function when the reciever supports more functions, including seven steps of forward and back speed, as well as a brake function. These speeds can be direct set or can be stepped up or down if the reciever is only controlling a single motor. What I wonder is if the current motors support these functions. I suppose I will have to wait until a new remote is made... or someone makes one themselves! X-D

[simonwillems]

Thanks for this information!

I am not really a scientist, so all those tables and figures don't do me much, but that probable change of remote control is interesting.

I wonder if the remote from the trainsets (7898 e.g.) will work on the powerfunctions as well... I do have the train and some powerfunctions, we are just not in the same place: the functions being in my parents house en me being in my own along with my train.

Does anybody know whether they interact?

[Siegfried]

Does anybody know whether they interact?

I have tried and they don't seem to. Since they both have the 7 speed capability I find this odd.... and disapointing.

[Ickelpete]

I would imagine that the new PF trains that have been talked about will hav a controller that will make use of all these functions.

I was reading over a Lugnet that someone has managed to use these extra function with a NXT as the controller. TLC have stated that there is more to come from the new Power Function range.

[Siegfried]

I was reading over a Lugnet that someone has managed to use these extra function with a NXT as the controller.

Do you have a link? :'-)

[brickbitz]

There is an article about using an RCX as a controller for power functions on LUGNET.

http://news.lugnet.com/general/?n=54443

I hope we are going to see a new remote with the PF trains.

[Siegfried]

There is an article about using an RCX as a controller for power functions on LUGNET.

Thanks! *sweet*

I hope we are going to see a new remote with the PF trains.

So am I! I'm hoping for remote points too! X-D

[Lasse D]

I believe it should be possible to use the IRLink-sensor for the NXT to exploit all this. I will look into it. With the rotate-sensors in the NXT-motors, one could make a very nice remote.

... and I who bought the Link-sensor for the NXT to be controlled by the PF-remote :-P

[EyesOnly]

I myself heard it via Technicbricks and it sure is looking promising. *sweet*

I've got such an urge to build but can't since i'm moving to my own flat in march. BTW if i'm right this post will change my group to citizen. Yeay. :-P X-D

[Lasse D]

I can see I have rushed it a bit too much.

I bought the IRLink-sensor from S@H, but HiTechnic has yet to release information about how to interact with the sensor. I don't know if I will have time to reverse engineer it and it appears nobody else has had the time (yet).

It would be nice to have a 7 speed remote by the end of this month. (Made using an NXT)

And a video camera X-D

[Brickthus]

...

I bought the IRLink-sensor from S@H, but HiTechnic has yet to release information about how to interact with the sensor. I don't know if I will have time to reverse engineer it and it appears nobody else has had the time (yet).

It would be nice to have a 7 speed remote by the end of this month. (Made using an NXT)

...

This post on lugnet.technic http://news.lugnet.com/general/?n=54493 provides a link to the extended code for BricXCC with NBC and NXC, to allow the full range of PF IR commands to be sent from an NXT via the HiTechnic IR link sensor. The lugnet post explains what commands to use for which applications.

I suppose you have already downloaded the NXT-G blocks from the HiTechnic website http://www.hitechnic.com/ . If not, go to Downloads and get the PF and Train IR Link Sensor blocks.

I have created a Brickshelf folder http://www.brickshelf.com/cgi-bin/gallery.cgi?f=297938 of electronic circuits to use with Power Functions parts, from simple PF lead mods http://www.brickshelf.com/gallery/mbellis/...d_mod_ccts1.jpg that allow an IR receiver to be powered from a 9V battery box to LED drivers and more complex stuff, such as a circuit to set train lights to the correct direction of travel (whatever the PWM speed setting) and keep them on when the train stops (assuming you have installed a PF IR receiver in a train, using a battery box as the power source). There are also circuits to interface PF parts to the NXT (using electrical connections rather than Infra Red).

I have successfully created NXT-G and NXC programs to put out a PF command waveform on pin 5 of an NXT sensor port. The trouble is that an NXT-G program has a minimum command delay time of 25ms and an NXC program has a minimum delay of 1ms, both too long to send a bit of the message (I need to go down to 157ms according to the TLG PF IR protocol document). This is why I have opted to use the HiTechnic IR link sensor rather than continue with my own hardware for the NXT-sends-PF-IR-messages application. I had envisaged making a 38kHz circuit to do the IR carrier wave but this is now not necessary.

Mark

[Lasse D]

What I wonder is if the current motors support these functions. I suppose I will have to wait until a new remote is made... or someone makes one themselves! X-D

I don't know if you have found the answer yet, but the motors support all speeds simply by switching between "on" and "brake" (not "float"). By changing the frequencies you get the different speeds. This is also how it is done in the NXT.

This post on lugnet.technic http://news.lugnet.com/general/?n=54493 provides a link to the extended code for BricXCC with NBC and NXC, to allow the full range of PF IR commands to be sent from an NXT via the HiTechnic IR link sensor. The lugnet post explains what commands to use for which applications.

(Snip a lot of good stuff)

Thank you very much Mark. I'm working in LeJos (Java for NXT), which has a pretty reactive approach to new NXT releases IMO. The work that the people have done in the other languages should help me implement it in LeJos without too much work.

Good luck on your future work with the PF electronics.