8 replies to this topic

[chief test pilot]

I see folks using NXT/Mindstorm servo motors to drive their Lego creations and combining them with the IR PF controllers. How exactly is this done? My basic understanding of Minstorm/NXT is that you program the functions you want thru the 'brick' (or brain) and then the creation will run autonomously. Is there a way to use the NXT equipment without the 'automation'?

How do you use the NXT items for R/C type control?

I am very familiar with traditional proportional R/C control as I fly RC helis and planes and have several RC cars as well.

How does NXT/Minstorm allow you to convert Lego vehicle to R/C type control?

jeff

[DLuders]

You can operate your Power Functions elements powered by the NXT brick, by using some extension cables.  The Power Functions Receiver's electric plate can be connected ON TOP OF the old-style 5306b "Electric, Wire with Brick 2 x 2 x 2/3 Pair" (the black cable below).  Connect your Power Functions motors to the PF Receiver, then connect the extension cables above to the NXT brick (instead of the PF Battery Box pictured below).

  

[chief test pilot]

DLuders, on 23 August 2012 - 08:36 PM, said:

You can operate your Power Functions elements powered by the NXT brick, by using some extension cables.  The Power Functions Receiver's electric plate can be connected ON TOP OF the old-style 5306b "Electric, Wire with Brick 2 x 2 x 2/3 Pair" (the black cable below).  Connect your Power Functions motors to the PF Receiver, then connect the extension cables above to the NXT brick (instead of the PF Battery Box pictured below).

  

So it looks like the NXT 'brick' replaces the PF battery box.

However, I want to use the NXT servo motors (not the PF motors). From what I understand the NXT servo motors have a different style connector than the PF motors.

What I want to know is how do you use the IR Tx/controller to operate the NXT servo motors....or can this even be done?

I'm trying to achieve proportional control like you would through a traditional RC transmitter. I would also like the steering servo motor to self center without having to resort to mechanical methods (i.e. rubber bands)

[sqiddster]

chief test pilot, on 23 August 2012 - 09:00 PM, said:

However, I want to use the NXT servo motors (not the PF motors). From what I understand the NXT servo motors have a different style connector than the PF motors.

What I want to know is how do you use the IR Tx/controller to operate the NXT servo motors....or can this even be done?

I'm trying to achieve proportional control like you would through a traditional RC transmitter. I would also like the steering servo motor to self center without having to resort to mechanical methods (i.e. rubber bands)

So, you want to control NXT motors with Power Functions.

Lego does sell converter cables, so it can be done. However, you will not get proportional control like the PF servo motor - rather, proportional control will adjust the speed of the motor. This is because the NXT motor is not a true servo - it is a continuous rotation motor with an encoder attached. The NXT brick is the only device that can read these encoder values - if you look closely, you will see that the encoder cables are removed in the converter cable.

Hope this cleared it up!

[DLuders]

@ Chief Test Pilot:  Snap the 8528 Converter Cable onto the end of the black Extension Cable above, to be able to clip into the NXT brick:

[Surly]

chief test pilot, on 23 August 2012 - 09:00 PM, said:

So it looks like the NXT 'brick' replaces the PF battery box.

However, I want to use the NXT servo motors (not the PF motors). From what I understand the NXT servo motors have a different style connector than the PF motors.

What I want to know is how do you use the IR Tx/controller to operate the NXT servo motors....or can this even be done?

I'm trying to achieve proportional control like you would through a traditional RC transmitter. I would also like the steering servo motor to self center without having to resort to mechanical methods (i.e. rubber bands)

CTP it is possible to do as you are requesting using a third party but lego certified product from Hitechnic NXT IR receiver

Another company supplies a sensor that allowa you to control your NXT with a playstation controller. There are lots of options.

cheers
Surly

[Aqualize]

chief test pilot, on 23 August 2012 - 06:48 PM, said:

I see folks using NXT/Mindstorm servo motors to drive their Lego creations and combining them with the IR PF controllers. How exactly is this done? My basic understanding of Minstorm/NXT is that you program the functions you want thru the 'brick' (or brain) and then the creation will run autonomously. Is there a way to use the NXT equipment without the 'automation'?

How do you use the NXT items for R/C type control?

I am very familiar with traditional proportional R/C control as I fly RC helis and planes and have several RC cars as well.

How does NXT/Minstorm allow you to convert Lego vehicle to R/C type control?

jeff

Apart from the answers you have gotten about the hardware. If one is using the NXT brick and NXT motors one could have a program that reads from a IR remote (I think). But the brick is also equipped with bluetooth. I don't know so much about the original firmware the NXT brick because one of the first thing I did was to flash it with the LejOS firmware. But I think this functionality works in both: you can connect with say a smartphone via bluetooth and have remote control the motors. As said, there are not true servo motors but can rotate quite slow so it is possible to emulate servo.
Another variant is to build a remote out of another NXT brick with a motor connected, as said it reads the rotational position of the motor (so it is kind of input also, not only output) and send commands via bluetooth to another NXT controlling say lego CAR.

Some example videos:
https://www.youtube....h?v=BX3Kim3O1AQ (there are other Apps)
https://www.youtube....h?v=KltnZBSvLu4 PF remotes as Surly describes
https://www.youtube....h?v=-au-gKBIqRk Controlling it via another NXT as I wrote above (skip to 3:00 into the video). I guess this principle is similar to your RC cars (the steering).
https://www.youtube....h?v=Ln1ObqxyGy0 I think this is cool as it shows that with NXT you could build quite an advanced remote and customize it for the task at hand.

[chief test pilot]

DLuders, on 23 August 2012 - 11:08 PM, said:

@ Chief Test Pilot:  Snap the 8528 Converter Cable onto the end of the black Extension Cable above, to be able to clip into the NXT brick:

Hmmm, I wonder if that would allow the NXT motor to connect to the PF IR receiver.......

If that would work then I can use the PF transmitters since one of my other goals is to use the unique shape of the NXT motors for space considerations.

[DLuders]

chief test pilot, on 25 August 2012 - 12:38 AM, said:

Hmmm, I wonder if that would allow the NXT motor to connect to the PF IR receiver.......

Yes, you could connect the Lego Power Functions Receiver's electrified plate ON TOP OF the black 2x2 electrified plate of the 8528 Converter Cable.