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@mts.net] Sent: dinsdag 13 oktober 2009 17:35 To: 'Marc Vermeersch'; 'Andrew Rich'; amsat-bb@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@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
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