Subject:
|
Re: How many people signed up for the NXT Developer's Program?
|
Newsgroups:
|
lugnet.robotics
|
Date:
|
Wed, 18 Jan 2006 21:35:52 GMT
|
Viewed:
|
2086 times
|
| |
|
|
In lugnet.robotics, Steve Hassenplug wrote:
> On Wed, January 18, 2006 3:28 pm, Mark Bellis wrote:
>
> > 5) Interface the NXT with earlier RCX devices so people can continue to get the
> > best out of their earlier products by using the NXT alongside them.
>
> There are things like this that people could actually start on right now. You know
> the RCX uses IR and you know the message format.
>
> You know the NXT has Bluetooth. The only thing you don't know is the message format.
>
> How much work can be done without that information? Most of the hardware?
>
> Why wait?
>
> Steve
Indeed - I'm not waiting, though I haven't done much work on point 5) yet.
I have been considering the circuit blocks in an interface between the new NXT
sensor port and a legacy RCX sensor. Of course I can't post anything yet, since
that would not be in the best interests of TLG or the AFOL community. It may be
that TLG has done this one for us with an eductional add-on.
My current assumptions about the interface are speculative, based on
bidirectional differential serial signals, using two pins each, leaving two for
the power supply. I look forward to the prospect of updating my assumptions
with some facts about the new hardware when I get hold of an NXT.
I take your point about using the IR and Bluetooth. This would be based as much
on firmware as hardware and I'm not a firmware expert. To avoid tinkering with
the firmware, what I originally meant about an NXT to RCX interface was a
hardware link between the two, such that each would see the other as the
equivalent of an NXT motor-tacho device. Knowing the sensor port protocols of
each unit would enable similar circuits to be created in the middle. It might
be that the RCX end would require one motor port as well as one sensor port,
since the NXT can control a motor and receive data from a rotation sensor on a
single port. The aim would be to make the RCX like an I/O processor in a
co-processor computer setup, controlling legacy motors, sensors and IR comms,
perhaps to other RCXs, with the NXT being the brains and controlling new sensors
and motors and live Bluetooth comms to the PC as it has more memory and could
cope with the bandwidth of the slave RCX's sensors too.
Another idea I'd like to try is drawing on the PC screen a map of where the NXT
robot was going, since each motor has tacho information that could be plotted.
I'll have to invest in a USB Bluetooth dongle for my PC as it's not a laptop.
This could be applied for tank robots as well as straight/differential drive
robots, where a low power motor does the turning but a high power motor does the
straight line driving, in a more polar co-ordinate fashion. The latter might be
easier to use for space mapping.
These ideas could be guided in the development program as they are all high
level at the moment. Although I have quite a few ideas, spending too much time
developing them in detail right now has the risk of the work being wasted if I
were not selected for the development program. Given that thousands of
applications are in already, the chances of selection are less than 1 in 10, so
my efforts must be balanced against the risk for now. I dunno how you rate that
as a reason for waiting, but I have yet to see whether I'll be able to progress
soon or whether I'll have to wait 6 months :-)
Mark
|
|
Message is in Reply To:
77 Messages in This Thread:
 
  
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
