[amsat-bb] Re: PIC rotator control
vk4tec at tech-software.net
Tue Oct 13 14:20:56 PDT 2009
Yes a small 10 inch laptop could do the work, predict would be used and
frequent kep updates
The laptop would also make decisions like
If two sats were up, what is the priority
It is a good project because it covers off
2. Programming PERL and ASM (PIC)
3. Installing and maintaining sofware essential to the function
----- Original Message -----
From: "Alan VE4YZ" <ve4yz at mts.net>
To: "'Marc Vermeersch'" <amvm at skynet.be>; "'Andrew Rich'"
<vk4tec at tech-software.net>; <amsat-bb at amsat.org>
Sent: Wednesday, October 14, 2009 1:35 AM
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
> tracker box), to run a rotator control box, to run a rotator. Sure it
> 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
> based TrakBox that does the radio and rotators.
> As I read you comments you are both querying the rotator controller, not
> 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
> 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
> 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
>> 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)
>> > -----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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