Kewl
Do you convert
"067" from ascii to binary and then compare that to an A/D value ?
I have worked out how to do binary to ascii
Sometime I wonder if just programming in perl on the LINUX side might be just as easy
I think potentiometers are used on most rotators ?
Unless stepper motors have entered the scene ?
Andrew
----- Original Message ----- From: "Marc Vermeersch" amvm@skynet.be To: "'Andrew Rich'" vk4tec@tech-software.net; amsat-bb@amsat.org Sent: Tuesday, October 13, 2009 9:44 PM Subject: RE: [amsat-bb] 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
--------------------------------------------------------------------------------
No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.421 / Virus Database: 270.14.12/2431 - Release Date: 10/12/09 13:01:00