Alt-BEAM Archive

Message #11232



To: beam@sgiblab.sgi.com
From: Bruce Robinson Bruce_Robinson@telus.net
Date: Tue, 29 Feb 2000 22:14:13 -0800
Subject: [alt-beam] Re: mini walker


Sorry for jumping in here a little late, but if it involves Nv nets, I'm
interested.

Ben Hitchcock wrote:
>
> You don't need a SE!
> Just attach the 1381 to power and ground, andconnect the output of the
> 1381 to the input of the microcore via a normal microcore cap.

Exactly. The first neuron fires on a rising input, and that's it.

> ... supply the +V pin on the 1381 from the last neuron in the chain.
> That way if the sun is REALLY bright the process keeps going around
> and around the loop while there's voltage available, rather than going
> through once and stopping.

Very nice, Ben. Elegent.

Also, you would probably want to eliminate startup impulses in the rest
of the chain (possibly a varation on Wilf's single process startup
circuit.

> ... No need to enable or disable the 240. And have the process fall
> off the end of the core - four neurons in a chain. This means that you
> get to gang two gates together per coil lead - two gates ganged up would
? give you enough juice to drive the walker, methinks.

Ben, do I have this right? Are you suggesting a '240 for the microcore
chain? Because I'm not sure a non-Schmitt inverter will work in an Nv
net (at least not without some extra external components.

Regards,
Bruce



11233 Tue, 29 Feb 2000 22:12:53 -0800 [alt-beam] Re: walker leg attachment beam@sgiblab.sgi.com Bruce Robinson "Travis D." wrote:
>
> Just out of curiousity, where do people generally buy
> the terminal blocks to attach the walker legs to the
> motor shafts (part #?)...how does one remove
> individual terminal blocks from a series of them, or
> do you just purchase individual ones?

Bought 'em at my local electrical distributer in ... oh, 1965. These
were for 120 VAC applications, so an electrical supply store may be an
alternative if your electronics supplier doesn't have any.

The ones I have consist of a set of metal tubes (well, almost a tube)
with a set screw near each end. They are molded into a flexible plastic
block. I just saw through the plastic from the back parallel to each
metal tube. I use a fine-tooth hacksaw blade, and as soon as I reach the
metal, I spread the plastic apart and pop out the metal. Then cut the
metal bit into two pieces, file up the ends of the cut, and I've got two
collars.

I've got a couple of types. They look the same from the outside, but the
size of the hole varies ... something to be aware of if you're tying to
fit to a specific motor.

Bruce



11234 Tue, 29 Feb 2000 22:50:30 -0700 [alt-beam] Re: mini walker beam@sgiblab.sgi.com Senior Speechless. :)

Wilf Rigter wrote:
>
> Hi Ben,
>
> Here is a blast from the past (June 99) : the LIGHT WALKER 1.0 design as
> shown in the attached schematic. In this design the SE function has been put
> inside the microcore loop. From another perspective this is a pentacore
> design. The 1381 acts like a combination Nu, PNC and SE trigger. Note that
> the 74HC14 and AC240 are powered up all the time. Normally the 4Nv outputs
> will all be high, the motors will be stopped and no current will flow. The
> solar panel will charge up the main cap and also the memory cap of the 1381.
> The memory cap ensures that the 1381 input voltage will not drop during the
> first process interval when the motor current starts to pull down the main
> capacitor voltage. When the 1381 fires it "injects" a process into the first
> Nv with a rising edge. This process ripples through the other Nvs and when
> the process reaches the last Nv it resets the memory cap of the 1381. This
> sequence is a 4Nv process cycle which causes the bot to advance by one step
> on each leg. Next the solar panel charges the main capacitor and the 1381
> memory cap back up and when fully charged the 1381 triggers the next process
> cycle. If there is enough charge on the main cap the SE fires almost
> immediately and the walker continues uninterrupted. This embedded SE design
> can be extended to 6Nv or 8Nv designs as well.
>
> The reverser circuit is quite a nice solution to the problem of early
> reverser time out when the LIGHT WALKER only walks intermittently. To avoid
> this problem, the reverser memory capacitor is discharged in steps, one
> process cycle at time, with about 7 or 8 cycles required to return to
> forward motion regardless of the time between steps. In addition the
> reverser circuit switching is synchronized with the start of each cycle to
> avoid the typical gait recovery time associated with asynchronous reverser
> circuit switching. This synchronous reverser idea can be applied to many
> walker designs and imho is a nice contribution to the state of the art of
> BEAM tech.
>
> The LIGHT WALKER still needs tactile inputs. Perhaps it can be left as an
> exercise for the reader to complete the full LIGHT WALKER design.
>
> enjoy
>
> Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
> tel: (604)590-7493
> fax: (604)590-3411
>
> <>
>
> > -----Original Message-----
> > From: Ben Hitchcock [SMTP:beh01@uow.edu.au]
> > Sent: Tuesday, February 29, 2000 7:38 PM
> > To: beam@sgiblab.sgi.com
> > Subject: Re: mini walker
> >
> > Here's an idea:
> >
> > You don't need a SE!
> > Just attach the 1381 to power and ground, andconnect the output of the
> > 1381 to the input of the microcore via a normal microcore cap. The 1381
> > gets to its switch-on voltage, introduces a process, and bang off it goes.
> > No need to enable or disable the 240. And have the process fall of f the
> > end of the core - four neurons in a chain. This means that you get to
> > gang two gates together per coil lead - two gates ganged up would give you
> > enough juice to drive the walker, methinks. And the nice thing about this
> > is that you only need one chip, one 1381, four caps and resistors, plus
> > your coils and solar panel and storage cap and that's it!
> >
> > Too easy.
> >
> > Ben
> >
> > > I was thinking about using a microcore instead of a master slave bicore.
> > > Either way, can pulses be stopped and resumed from their last position?
> > > I'm wondering if an Nv chain that is initiated by the SE firing would
> > > work. Switch the source to a different coil and polarity on each of 4
> > > steps, and then fall off the end. Allow the SE to charge to full. It'd
> > > store enough power for a complete step cycle. If there were enough
> > > power, I assume the SE could continuously fire the start of the Nv
> > > chain, till light levels drop and it would then rely on firing
> > > intermittently, till it looses it's charge again.
> > >
> > > Has anyone made such a circuit before???
> > >
> > > Would the Chloroplast be suitable for this purpose, and how can I get a
> > > single pulse out of it, with a second sustained pulse going to the
> > > driver (I suppose 2 chips would be acceptable, if necessary). If the
> > > driver powers the coils, then would it be possible to attach it to the
> > > steady voltage output of the Chloroplast SE and the pulse to the
> > > trigger, and have a very high dropout level, so it shuts down right
> > > away, waiting for the next charge before refiring???
> > >
> > >
> > > Ben Hitchcock wrote:
> > > >
> > > > Hi,
> > > >
> > > > > What
> > > > > would be best? I thought of an SE type system with a timed trigger.
> > Is
> > > > > there a way to create an SE that triggers different pulse outputs in
> > > > > chain? I'll play with circuits. That's what we're here for anyway.
> > New designs!
> > > >
> > > > How about using a shift register? Attach the SE to an enable pin on
> > your
> > > > motor driver (74xx240) and also to the clock pin on the shift
> > register.
> > > > You'll also need to attach the fourth (or is it fifth?) pin of the
> > shift
> > > > register to the data in
> > > > pin, and somehow start a pulse when there aren't any in the stream...
> > > > you'd need four diodes (one from each gate on the shift register) a
> > > > resistor and an inverter to create a pulse if none existed in the
> > chain.
> > > >
> > > > Maybe a shift register isn't such a good idea after all... 2 IC's
> > instead
> > > > of one... Perhaps ye olde microcore could be adapted to do it.
> > > >
> > > > Good luck!
> > > >
> > > > Hmm maybe the bot won't be able to steer using this setup. no matter,
> > it
> > > > will look pretty cool.
> > > >
> > > > Ben
> > >
> > > --
> > >
> > >
> > > Richard Piotter The Richfiles Robotics & TI web page:
> > > richfile@rconnect.com http://richfiles.calc.org
> > >
> > > -- Make Money by Simply Surfing the Net or responding to E-Mail!!!
> > > -- Click below!!!
> > >
> > > http://www.alladvantage.com/go.asp?refid=ATL147
> > > http://www.spedia.net/cgi-bin/dir/tz.cgi?run=show_svc&fl=8&vid=329630
> > >
> >
> >
> > --
> > Nothing is foolproof to a sufficiently talented fool.
>
> ------------------------------------------------------------------------
> Name: lightwalker.gif
> lightwalker.gif Type: GIF Image (image/gif)
> Encoding: base64



11235 Tue, 29 Feb 2000 23:15:24 -0600 [alt-beam] Re: mini walker beam@sgiblab.sgi.com Richard Piotter Sounds good to me!
I love the ideas here!

I appreciate the help. More comments are welcome.

I can't wait to finish this thing! :)


Ben Hitchcock wrote:
>
> Oh just one more thing,
> supply the +V pin on the 1381 from the last neuron in the chain. That way
> if the sun is
> REALLY bright the process keeps going around and around the loop while
> there's voltage available, rather than going through once and stopping.
>
> Ben
>
> > Here's an idea:
> >
> > You don't need a SE!
> > Just attach the 1381 to power and ground, andconnect the output of the
> > 1381 to the input of the microcore via a normal microcore cap. The 1381
> > gets to its switch-on voltage, introduces a process, and bang off it goes.
> > No need to enable or disable the 240. And have the process fall of f the
> > end of the core - four neurons in a chain. This means that you get to
> > gang two gates together per coil lead - two gates ganged up would give you
> > enough juice to drive the walker, methinks. And the nice thing about this
> > is that you only need one chip, one 1381, four caps and resistors, plus
> > your coils and solar panel and storage cap and that's it!
> >
> > Too easy.
> >
> > Ben
> >
> > > I was thinking about using a microcore instead of a master slave bicore.
> > > Either way, can pulses be stopped and resumed from their last position?
> > > I'm wondering if an Nv chain that is initiated by the SE firing would
> > > work. Switch the source to a different coil and polarity on each of 4
> > > steps, and then fall off the end. Allow the SE to charge to full. It'd
> > > store enough power for a complete step cycle. If there were enough
> > > power, I assume the SE could continuously fire the start of the Nv
> > > chain, till light levels drop and it would then rely on firing
> > > intermittently, till it looses it's charge again.
> > >
> > > Has anyone made such a circuit before???
> > >
> > > Would the Chloroplast be suitable for this purpose, and how can I get a
> > > single pulse out of it, with a second sustained pulse going to the
> > > driver (I suppose 2 chips would be acceptable, if necessary). If the
> > > driver powers the coils, then would it be possible to attach it to the
> > > steady voltage output of the Chloroplast SE and the pulse to the
> > > trigger, and have a very high dropout level, so it shuts down right
> > > away, waiting for the next charge before refiring???
> > >
> > >
> > > Ben Hitchcock wrote:
> > > >
> > > > Hi,
> > > >
> > > > > What
> > > > > would be best? I thought of an SE type system with a timed trigger. Is
> > > > > there a way to create an SE that triggers different pulse outputs in
> > > > > chain? I'll play with circuits. That's what we're here for anyway. New designs!
> > > >
> > > > How about using a shift register? Attach the SE to an enable pin on your
> > > > motor driver (74xx240) and also to the clock pin on the shift register.
> > > > You'll also need to attach the fourth (or is it fifth?) pin of the shift
> > > > register to the data in
> > > > pin, and somehow start a pulse when there aren't any in the stream...
> > > > you'd need four diodes (one from each gate on the shift register) a
> > > > resistor and an inverter to create a pulse if none existed in the chain.
> > > >
> > > > Maybe a shift register isn't such a good idea after all... 2 IC's instead
> > > > of one... Perhaps ye olde microcore could be adapted to do it.
> > > >
> > > > Good luck!
> > > >
> > > > Hmm maybe the bot won't be able to steer using this setup. no matter, it
> > > > will look pretty cool.
> > > >
> > > > Ben
> > >
> > > --
> > >
> > >
> > > Richard Piotter The Richfiles Robotics & TI web page:
> > > richfile@rconnect.com http://richfiles.calc.org
> > >
> > > -- Make Money by Simply Surfing the Net or responding to E-Mail!!!
> > > -- Click below!!!
> > >
> > > http://www.alladvantage.com/go.asp?refid=ATL147
> > > http://www.spedia.net/cgi-bin/dir/tz.cgi?run=show_svc&fl=8&vid=329630
> > >
> >
> >
> > --
> > Nothing is foolproof to a sufficiently talented fool.
> >
>
> --
> Nothing is foolproof to a sufficiently talented fool.

--


Richard Piotter The Richfiles Robotics & TI web page:
richfile@rconnect.com http://richfiles.calc.org

-- Make Money by Simply Surfing the Net or responding to E-Mail!!!
-- Click below!!!

http://www.alladvantage.com/go.asp?refid=ATL147
http://www.spedia.net/cgi-bin/dir/tz.cgi?run=show_svc&fl=8&vid=329630



11236 Sun, 27 Feb 2000 11:51:31 -0500 Re: which 1381 trigger
> In a message dated 2/29/00 8:33:07 PM Eastern Standard Time,
walkau@eagle.ca
> writes:
>
> > i was looking at getting the 1381J (2.7v). does it really matter that
> > the solar cell has a higher rating? is it just that the 1381 will
> > trigger when it reaches the 2.7v mark?
> Yep, it'll just get there faster. It'll give better low light performance
as
> well. I'd go with an "N" myself.
>
> See ya,
> Jim
> http://www.geocities.com/SoHo/Exhibit/8281/beamart.html
> ICQ# 55657870
>

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