Mindstorms RCX 2.0 with PF?

[Nazgarot]

Hi,

I have an old RCX 2.0 module, and wonder if it can be used with the new PF system. I know it doesn't support the PF protocols out of the box, but maybe there is some custom software for it? I want to use it as a mixer unit between 3 PF motors, and was hoping to control it from a PF remote. I could put in a PF receiver to receive and activate inputs on the RCX, but I still don't know if that would work.

If anyone has experience with RCX/PF combinations, or know of any resource sites with information on PF and RCX protocols or custom software, please help me.

I'll be testing this anyway, but it would be a great help to know the protocols of the components. I have little experience with programming, and haven't used the RCX module much, but I have a good basis in electronics and C++.

Thanks

-ED-

EDIT: Added link to RCX 2.0 on brickLink

Edited August 11, 2012 by Nazgarot

[DLuders]

The RCX needs a 8886 Power Functions Extension Wire (first picture below) to operate Power Functions motors. The Power Functions Receiver's electrified plate clips ON TOP OF the 5306b "Electric, Wire with Brick 2 x 2 x 2/3 Pair" that (in turn) is connected to the RCX brick.

Edited August 11, 2012 by DLuders

[DLuders]

On his website, Philo (Philippe Hurbain) has links to old Mindstorms RCX2 software. He also has this webpage that shows how to make a Power Functions NXT Remote Control. Perhaps there is a way of blending the two....

You may also want to consider the HiTechnic NXT IR Link Sensor, which has some RCX capabilities: "Control LEGO R/C trains and other motorized LEGO sets with the HiTechnic IRLink Sensor for the Mindstorms NXT. The IRLink uses Infrared signals to communicate with trains, Power Functions Motor controller and the Mindstorms RCX . Control the speed and direction of up to three LEGO R/C trains (7897 and 7898) and other sets including the new Technic Motorized Bulldozer (8275) and the Monster Dino (4958). The IRLink enables NXT programs to read values from RCX sensors and control motors connected to the RCX."

The Lego 8884 Power Functions IR Receiver has its protocols listed on the "Element Spec" PDF "Download" shown at the top-right of this Lego webpage: http://powerfunctions.lego.com/en-us/ElementSpecs/Default.aspx#8884 .

[sqiddster]

I know it doesn't support the PF protocols out of the box

I didn't know this, so are you saying that if you hook up the PF motors with extension wires, it doesn't work? Interesting.

[ciken]

I didn't know this, so are you saying that if you hook up the PF motors with extension wires, it doesn't work? Interesting.

that wil work but the ir protocol will not work

[Nazgarot]

that wil work but the ir protocol will not work

Yes, exactly. That is the problem with this combination. I was hoping to use the RCX as a receiver/mixer for two IR channels, and 3 motors. I can compromise with using an IR receiver in addition to the RCX, but then I would have to include another battery box or modify the RCX to have a battery connection for the IR receiver. This would still not give me a possibility to use the proportional action of the servo motor, or the more general speed control for other PF elements. But I'm not sure that those functions can be used anyway as I don't know if the RCX has control outputs (C1 and C2). The PF system works by applying 2 power connections (positive and ground) and two control connections (C1 and C2) that will give you variable speed or for the servo proportional control.

The question would be; Does anyone know if the RCX has 4 connections, or is it only positive and ground? And does anyone have a resourse with alternative software for RCX that supports PF IR protocols?

@DLuders: Thanks. That may help a lot. I've just checked out Philos page, but still need to experiment a bit more before I can say it solved my problems. But maybe buying the NXT and a HiTech IRLink Sensor is the only way to solve my problem...

[DLuders]

@ Nazgarot: Have you seen this RCX Internals webpage? It has lots of RCX byte code.

Bob Kojima wrote an article on his LEGO Robotics webpage about "Power Function control with RCX and BrickOS" -- "Now you can use your RCX to control LEGO Power Functions. That's right the RCX can act as a PF remote control but it can do something that the PF remote can't do yet. The RCX can do PWM with your PF reciever modules.

You do not need to install BrickOS to get this to work. The executable that you need and the BrickOS firmware are included

in this packet.

Get it here: <http://www.fial.com/bob/lego/PowerFunctions.zip>

The zip file includes a sample program that uses 2 rotation sensors to control the PWM on the red and blue ports it can also send controls to all 4 PF chanels. Also included is a .h file that impliments the complete Power functions protocol for BrickOS."

Alas, the 4-year-old link to that ZIP file is broken, but I sent a Eurobricks Private Message (PM) to Bob Kojima and you got a copy of that same message. Perhaps he could send you the ZIP file if he still has it....

[sqiddster]

that wil work but the ir protocol will not work

Oh, so you want to communicate with the receivers with IR... That's actually pretty interesting. I'd like to see how that turns out!

[Bob Kojima]

My RCX software that controls PF motors can be found here look under the software section.

please let me know if you need help getting it working.

bob

[DLuders]

Thanks, Bob! Your "Power Functions on the LEGO RCX" software download looks very useful -- "Now you can use your RCX to control LEGO Power Functions. That's right the RCX can act as a PF remote control but it can do something that the PF remote can't do yet. The RCX can do PWM with your PF receiver modules. You do not need to install BrickOS to get this to work. The executable that you need are included in this packet."

Edited August 12, 2012 by DLuders

[Nazgarot]

Thanks to both of you!! That will probably solve my problem.

I'll post my results in this tread, but it might take a while as I don't have much time to tinker with my Lego any more...

-ED-

[Bricktrain]

is using the RCX remote a possibility, that can control all 3 outputs http://www.bricklink.com/catalogItemIn.asp?P=x124&in=S

[DLuders]

@ Bricktrain: Yes, one could use the 9738 Lego Mindstorms RCX Remote Control unit, but since they are SOLD OUT on Bricklink and TLG does not sell the 1998 part anymore, it's not really an option for 2012 (14 years later).

[Bricktrain]

@ Bricktrain: Yes, one could use the 9738 Lego Mindstorms RCX Remote Control unit, but since they are SOLD OUT on Bricklink and TLG does not sell the 1998 part anymore, it's not really an option for 2012 (14 years later).

sold out?

http://www.bricklink.com/search.asp?itemID=17987&colorID=11

http://www.bricklink.com/search.asp?itemID=5933

and also available in the ultimate accessory set http://www.bricklink.com/search.asp?itemID=4370

[mikezang]

Thanks, Bob! Your "Power Functions on the LEGO RCX" software download looks very useful -- "Now you can use your RCX to control LEGO Power Functions. That's right the RCX can act as a PF remote control but it can do something that the PF remote can't do yet. The RCX can do PWM with your PF receiver modules. You do not need to install BrickOS to get this to work. The executable that you need are included in this packet."

Hi, did you use this PF101 to control PF receiver by RCX? i also tried but even I rotated axle in rotation sensor, PF receiver doesn't action, can you help me?