Ideas please

Started by hrifai February 13, 2005

Hi all

I am looking for an interesting (easy to build) project that
involves any mechanical idea + PIC16F84 !!!!!!!

The point is that I don't have to design the circuit "not my part"
and my team insist on something very interesting

Can anyone please help ???



How about providing quartz accuracy for a pendulum clock!

Measure the period of the pendulum of your average grandmother using
maybe an interrupted light beam, and provide an on-off method to damp
(or not) its swing.

In general, pendulum clocks tend to go faster when their energy source
wanes (small swings) and are slower when they are fully powered (yeah
baby yeah swing)

The pendulum formula sqrt(length/g)/(2*pi) is only accurate for small
amplitudes of theta, but everyone seems to forget that.

If battery powered you can actually achieve good accuracy by simply
providing a constant current source through the clock circuit. But
that's too easy.

So you should do it in a way that would make Ruth Goldberg proud -
plenty of physical (air, magnetic, audio, liquid flow) things going on
and the PIC device used simply to orchestrate everything in a crystal
clock source controlled "timely" fashion.

Extra credit for using solar power and no physical contact for your
perpetual chaos machine with the PIC circuitry. Meaning, if your PIC
dies, it continues to function more or less as before - but once you
bring it into the arena - whamo - atomic precision.

That should teach your team to outsource their lack of imagination ;)

Rahul
--- In , "hrifai" <hrifai@y...> wrote:
>
> Hi all
>
> I am looking for an interesting (easy to build) project that
> involves any mechanical idea + PIC16F84 !!!!!!!
>
> The point is that I don't have to design the circuit "not my part"
> and my team insist on something very interesting
>
> Can anyone please help ???



Excellent idea! I work on clocks as a hobby/profession - the power
problem is probably overstated
since most grandfather/mother clocks run on weight, which doesn't change
much as the clock runs
down (just the added weight of the chain/cable). But temperature change
and pendulum swing are
something else interely.

Good suggestion!

Paul

rrkarnik wrote:

>How about providing quartz accuracy for a pendulum clock!
>
>Measure the period of the pendulum of your average grandmother using
>maybe an interrupted light beam, and provide an on-off method to damp
>(or not) its swing.
>
>In general, pendulum clocks tend to go faster when their energy source
>wanes (small swings) and are slower when they are fully powered (yeah
>baby yeah swing)
>
>The pendulum formula sqrt(length/g)/(2*pi) is only accurate for small
>amplitudes of theta, but everyone seems to forget that.
>
>If battery powered you can actually achieve good accuracy by simply
>providing a constant current source through the clock circuit. But
>that's too easy.
>
>So you should do it in a way that would make Ruth Goldberg proud -
>plenty of physical (air, magnetic, audio, liquid flow) things going on
>and the PIC device used simply to orchestrate everything in a crystal
>clock source controlled "timely" fashion.
>
>Extra credit for using solar power and no physical contact for your
>perpetual chaos machine with the PIC circuitry. Meaning, if your PIC
>dies, it continues to function more or less as before - but once you
>bring it into the arena - whamo - atomic precision.
>
>That should teach your team to outsource their lack of imagination ;)
>
>Rahul
>--- In , "hrifai" <hrifai@y...> wrote: >>Hi all
>>
>>I am looking for an interesting (easy to build) project that
>>involves any mechanical idea + PIC16F84 !!!!!!!
>>
>>The point is that I don't have to design the circuit "not my part"
>>and my team insist on something very interesting
>>
>>Can anyone please help ???
>>
> >to unsubscribe, go to http://www.yahoogroups.com and follow the instructions
>Yahoo! Groups Links




> So you should do it in a way that would make Ruth Goldberg proud -
> plenty of physical (air, magnetic, audio, liquid flow) things going on
> and the PIC device used simply to orchestrate everything in a crystal
> clock source controlled "timely" fashion.
>
> Extra credit for using solar power and no physical contact for your
> perpetual chaos machine with the PIC circuitry. Meaning, if your PIC
> dies, it continues to function more or less as before - but once you
> bring it into the arena - whamo - atomic precision.

You do realise that the accuracy of an average crystal is not
necesarrily suprior to a pendulum clock?

Wouter van Ooijen

-- -------
Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: www.voti.nl/hvu




----- Original Message -----
From: "Wouter van Ooijen" <>

>
> > So you should do it in a way that would make Ruth Goldberg proud -
> > plenty of physical (air, magnetic, audio, liquid flow) things going
on
> > and the PIC device used simply to orchestrate everything in a
crystal
> > clock source controlled "timely" fashion.
> >
> > Extra credit for using solar power and no physical contact for your
> > perpetual chaos machine with the PIC circuitry. Meaning, if your PIC
> > dies, it continues to function more or less as before - but once you
> > bring it into the arena - whamo - atomic precision.
>
> You do realise that the accuracy of an average crystal is not
> necesarrily suprior to a pendulum clock?

You're a smart guy Wouter, but I'm still surprised that you knew that.
Not many people fully realize the accuracy of a great many timepieces
far over 100 years old. I have a Seth Thomas 8-day double-decker empire
clock circa 1890 that keeps time to within 30 seconds/week putting it
close to the stated accuracy of allot of crystals. It's nothing really
special, just an ordinary mantle clock for an elitist Victorian of the
time. ;-) Each weight is around 15 pounds.

Almost identical to this one, but mine's in better shape:
http://www.antiqueclockspriceguide.com/pages/clock4429.php

As you probably know, laboratory/observatory clocks of the time were
*far* more impressive.




Doh! I guess it might help to be able to trim the oscillation modes
and keep the thingy at a constant temperature. More fun to do that
using the PIC.

Some readily available consistent time bases include a 19 KHz FM radio
stereo pilot tone.

Or the common household power supply (50/60Hz) which is supposedly
ordained to be very accurate - over time.

Or ...... maybe the "team" should make a pendulum-accuracy based PLL
clock!

I've been thinking of a "clock" which works as follows:

a) Solar cell powered. Initialized with absolutely no information -
except a bunch of astronommical equations.
b) You leave it outdoors, anywhere on the planet (well maybe not in
too high latitudes)
c) Every day it gets powered by sunlight which enables it to track the
traversal of the sun across the sky.
d) At night or on cloudy days it simply sleeps.
e) Over several months, if not years, it determines its location
(latitude) to figure out local time for that location very accurately,
including calendar information.
f) The clock will extend its flexible and positionable arms to set up
an accurately shaped gnomon and also draw a sundial pattern around
itself, including corrections for the annual equation of time.
g) Once that is done, the clock is ready and can go to sleep except
for slight corrections when necessary. --- In , "Wouter van Ooijen" <wouter@v...> wrote:
> > So you should do it in a way that would make Ruth Goldberg proud -
> > plenty of physical (air, magnetic, audio, liquid flow) things going on
> > and the PIC device used simply to orchestrate everything in a crystal
> > clock source controlled "timely" fashion.
> >
> > Extra credit for using solar power and no physical contact for your
> > perpetual chaos machine with the PIC circuitry. Meaning, if your PIC
> > dies, it continues to function more or less as before - but once you
> > bring it into the arena - whamo - atomic precision.
>
> You do realise that the accuracy of an average crystal is not
> necesarrily suprior to a pendulum clock?
>
> Wouter van Ooijen
>
> -- -------
> Van Ooijen Technische Informatica: www.voti.nl
> consultancy, development, PICmicro products
> docent Hogeschool van Utrecht: www.voti.nl/hvu





All of which makes John Harrison's navigational watch look
spectacular: in 1762, during an 81 day voyage, the H4 lost 5 SECONDS!

This would create a positional error of perhaps 1.25 nautical miles
and even on a small boat the visible horizon is about 3 nautical
miles. I could live with that kind of accuracy!

Of course, sextant errors, ship motion, almanac accuracy, etc. would
all add to the error but time is the critical factor and Harrison
had that down to an art.

--- In , "michael brown" <spam-me@h...> wrote:
>
>
> ----- Original Message -----
> From: "Wouter van Ooijen" <wouter@v...>
>
> >
> > > So you should do it in a way that would make Ruth Goldberg
proud -
> > > plenty of physical (air, magnetic, audio, liquid flow) things
going
> on
> > > and the PIC device used simply to orchestrate everything in a
> crystal
> > > clock source controlled "timely" fashion.
> > >
> > > Extra credit for using solar power and no physical contact for
your
> > > perpetual chaos machine with the PIC circuitry. Meaning, if
your PIC
> > > dies, it continues to function more or less as before - but
once you
> > > bring it into the arena - whamo - atomic precision.
> >
> > You do realise that the accuracy of an average crystal is not
> > necesarrily suprior to a pendulum clock?
>
> You're a smart guy Wouter, but I'm still surprised that you knew
that.
> Not many people fully realize the accuracy of a great many
timepieces
> far over 100 years old. I have a Seth Thomas 8-day double-decker
empire
> clock circa 1890 that keeps time to within 30 seconds/week putting
it
> close to the stated accuracy of allot of crystals. It's nothing
really
> special, just an ordinary mantle clock for an elitist Victorian of
the
> time. ;-) Each weight is around 15 pounds.
>
> Almost identical to this one, but mine's in better shape:
> http://www.antiqueclockspriceguide.com/pages/clock4429.php
>
> As you probably know, laboratory/observatory clocks of the time
were
> *far* more impressive.




--- In , "hrifai" <hrifai@y...> wrote:
>
> Hi all
>
> I am looking for an interesting (easy to build) project that
> involves any mechanical idea + PIC16F84 !!!!!!!
>

I'm thinking to this from a long time: imagine a huge hammer
in a knock position, locked by a small relay mechanism.
A 220V 100W bulb plugged into the mains below him.
An ethernet conection to a PIC16F84 and a camera on to the show.
The web surfer see a button and by pushing it, the hammer will blow
the bulb. Everything wievable on the internet.

Did you felt you're living for doing something grandious ?

:)

best regards,
Vasile
http://surducan.netfirms.com




--- Wouter van Ooijen <> wrote:

> > So you should do it in a way that would make Ruth Goldberg proud -
> > plenty of physical (air, magnetic, audio, liquid flow) things going
> on
> > and the PIC device used simply to orchestrate everything in a
> crystal
> > clock source controlled "timely" fashion.
> >
> > Extra credit for using solar power and no physical contact for your
> > perpetual chaos machine with the PIC circuitry. Meaning, if your
> PIC
> > dies, it continues to function more or less as before - but once
> you
> > bring it into the arena - whamo - atomic precision.
>
> You do realise that the accuracy of an average crystal is not
> necesarrily suprior to a pendulum clock?
>
> Wouter van Ooijen
>
> -- -------
> Van Ooijen Technische Informatica: www.voti.nl
> consultancy, development, PICmicro products
> docent Hogeschool van Utrecht: www.voti.nl/hvu

Right you are. Before the government came up with atomic standards,
believe it or not, most TV station, power stations, etc. used a
pendulum clock. Our standard was right there in master control. This
is not 50 years ago, maybe 30.

Chad

=====
My software has no bugs, only undocumented features.

__________________________________________________




And you only need do it once, then play back the video
whenever the web surfer hits the button.
Was it real or was it memorbits?

Vasile Surducan wrote:

>
> --- In , "hrifai" <hrifai@y...> wrote:
>
>>Hi all
>>
>>I am looking for an interesting (easy to build) project that
>>involves any mechanical idea + PIC16F84 !!!!!!!
> > I'm thinking to this from a long time: imagine a huge hammer
> in a knock position, locked by a small relay mechanism.
> A 220V 100W bulb plugged into the mains below him.
> An ethernet conection to a PIC16F84 and a camera on to the show.
> The web surfer see a button and by pushing it, the hammer will blow
> the bulb. Everything wievable on the internet.
>
> Did you felt you're living for doing something grandious ?
>
> :)
>
> best regards,
> Vasile
> http://surducan.netfirms.com