[amsat-bb] Re: PIC rotator control

[Gregg Wonderly]

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 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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> 
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