Nice idea Gregg. We do a few near space balloons each year and I have been bugging some other folks ( because I don't write code ) to consider 2 projects:
1 - rotator control in a moving vehicle to keep a small yagi such as an Arrow pointed at the APRS signal.
2 - antenna parking based on data from a home WX station such as those commonly beaconing on APRS systems.
I will copy the 3 of you, Marc, Andrew and Gregg off list with more details.
-----Original Message----- From: Gregg Wonderly [mailto:w5ggw@cox.net] Sent: October 13, 2009 11:33 AM To: Alan VE4YZ Cc: 'Marc Vermeersch'; 'Andrew Rich'; amsat-bb@amsat.org Subject: Re: [amsat-bb] Re: PIC rotator control
I'd like to suggest that such systems should have a compass input from a GPS too so that as I'm driving mobile, I can have such a rotator strapped in the back of my truck, and be able to have it track the pass so I can hear it, and grab the mic and talk if I need to. I'd also use this for mobile ATV work to keep a beam pointed at our ATV repeater.
Gregg Wonderly W5GGW
Alan VE4YZ wrote:
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@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Marc Vermeersch Sent: October 13, 2009 6:45 AM To: 'Andrew Rich'; amsat-bb@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@amsat.org
[mailto:amsat-bb-bounces@amsat.org]
On Behalf Of Andrew Rich Sent: dinsdag 13 oktober 2009 12:22 To: amsat-bb@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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Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. Opinions expressed are those
of the author.
Not an AMSAT-NA member? Join now to support the amateur
satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb