[amsat-bb] Re: PIC rotator control

[Marc Vermeersch]

Hi Alan,

> > I have a PIC based solution currently in the prototype stage.
> > It uses a
> > PIC18F4455 and drives a Yeasu AZ/EL rotor without the Yeasy
> > control box.

My setup is NOT using the rotator control box; it drives the rotator
directly.

> > - Eventually I want to run a tracking algorithm in the PIC too

In the future I plan to run a tracking algorithm on the embedded processor
to become independent from the PC.

That would result in a autonomous box for on-the-road activity. Add a GPS
and a compass and you can install it on a truck.

I'm currently also experimenting with solid state AZ/EL measurement. Final
goal is to stick a small box on the handle of an arrow antenna and get
Up/Down and Left/Right indication by LED's.

BR,
--
/\/\arc



> -----Original Message-----
> From: Alan VE4YZ [mailto:ve4yz at mts.net]
> Sent: dinsdag 13 oktober 2009 17:35
> To: 'Marc Vermeersch'; 'Andrew Rich'; amsat-bb at amsat.org
> Subject: RE: [amsat-bb] Re: PIC rotator control
> 
> Marc, Andrew and the group...
> 
> It has always struck me as being odd that we use a PC to run a PC(PIC
> based
> tracker box), to run a rotator control box, to run a rotator.  Sure it
> works
> but the absurdity of this really hits home when you disassemble your
> shack
> to take it all out for Field Day or an EmComm exercise.  I don't!  I
> leave
> the PC and LVBtracker at home and take my good old 1990's preprogrammed
> PIC
> based TrakBox that does the radio and rotators.
> 
>  http://www.tapr.org/kits_trakbox.html
> 
>  http://picasaweb.google.com/ve4yz.alan/TrakboxRebuild2004#
> 
> As I read you comments you are both querying the rotator controller,
> not the
> rotators, to find out where the AL and EL are.
> 
> With the power of today's inexpensive netbooks or the OLPC is there not
> a
> solution where the "embedded system is the netbook"?  Then, all that
> would
> be required between the PC and the rotator is a black box with relays
> to
> power the rotators and a small A/D interface to take the data from the
> pots
> and pass it onto the PC?  A black box easily assembled by most hams.
> If
> open source, then others can do whatever is necessary create mods for
> various rotator systems such as pulse counting for stepper motors
> instead of
> A/D etc
> 
> My 2 cents.... Alan
> 
> 
> 
> > -----Original Message-----
> > From: amsat-bb-bounces at amsat.org
> > [mailto:amsat-bb-bounces at amsat.org] On Behalf Of Marc Vermeersch
> > Sent: October 13, 2009 6:45 AM
> > To: 'Andrew Rich'; amsat-bb at amsat.org
> > Subject: [amsat-bb] Re: PIC rotator control
> >
> > Hi Andrew,
> >
> > I have a PIC based solution currently in the prototype stage.
> > It uses a
> > PIC18F4455 and drives a Yeasu AZ/EL rotor without the Yeasy
> > control box.
> >
> > The PC sends information to the PIC (RequestedAZ,RequestedEL)
> > and the PIC sends back status information to the PC
> > (RequestedAZ,RequestedEL,CurrentAZ,CurrentEL,Status).
> >
> > Everything is done by the PIC:
> > - Control of the rotor motors based on either
> > move-every-n-seconds or move-when-error-angle-is-greater-than-n
> > - Measurement of the actual AZ/EL with 10-bit resolution
> > - Parking when no signal has been coming from the PC in x
> > seconds -or- an explicit park command is received
> > - Stall protection
> > - Some horizon protection: EL cannot go below x when AZ is y
> > to avoid pointing into my neighbors' bedroom.
> > - Over the top rotor control (under development)
> > - ...
> >
> > I'm using a PIC18F4455 and it is very well capable of doing
> > all that and more. I have chosen this path for several reasons:
> > - Eventually I want to run a tracking algorithm in the PIC too
> > - To make the control loop shorter
> > - To avoid dependence on the PC part specifically on safety
> > related aspects like stall control and horizon protection.
> > - To explore the capabilities of the PIC18
> > - (Because it's my job to do embedded HW/SW)
> >
> > BR,
> > --
> > /\/\arc
> >
> > > -----Original Message-----
> > > From: amsat-bb-bounces at amsat.org
> > [mailto:amsat-bb-bounces at amsat.org]
> > > On Behalf Of Andrew Rich
> > > Sent: dinsdag 13 oktober 2009 12:22
> > > To: amsat-bb at amsat.org
> > > Subject: [amsat-bb] PIC rotator control
> > >
> > > Hello
> > >
> > > I am re-visting a rotator controller.
> > >
> > > I am curious, should I push the processing of the "compare
> > and make a
> > > decision" onto the PIC, or pull that function back into the PC ?
> > >
> > > PC is LINUX
> > >
> > > I/O is serial
> > >
> > > PIC is 16F877
> > >
> > > Andrew VK4TEC
> > >
> > > _______________________________________________
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> > > author.
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> >
> > _______________________________________________
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> > the author.
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> >