Re: Making your own rotator controller
Hi Andrew,
Not exactly an answer to your question, but still:
Some years (~1995..1996) ago I built my own tracker as well. Was the time when the LVB trackers etc were not available. Only the expensive Kansas City tracker (expensive).
My system is still operational. Bertus, PE1KEH, wrote in PASCAL the tracking SW (input: kepler, output: sat position). I added to that the controlling of the rotors. All corrections mentioned below (overshoot etc) are done in PASCAL in the PC. That sends and integer value to the ST6 (like your PIC) which does only one thing extra: check if the integer exceeds the allowed maximum right or left position (in case max left is at 4.5V where your range maybe 0..5V).
Items to consider next to straight degrees2voltage conversion: - overshoot (when you stop, the rotor actually moved still a tiny bit) - thresholds (to avoid oscillation & to much shaking)
8 bits give enough accuracy, I used a pot.meter to convert the voltage of the rotor voltage from eg 0..20V down to 0..5V.
http://home.vianetworks.nl/users/hamoen/pa3guo/zb_rtr_ctrl.html (includes my poor PASCAL routines)
Of course it took a terrible amount of effort/time, which I had only back then, so today I would buy an LVB tracker :-)
Still - this was one of the most satisfying projects I ever did. Seeying you home-made system following the bright ISS in the darkness of the night is soooo cool !
Have fun & success
Henk, PA3GUO http://www.qsl.net/pa3guo
To better phrase this:
Most likely while the rotor is moving you are sampling the position to find out if it's already time to stop.
For the CPU (PIC or ST6) the AD conversion takes time, and also for the SW then to take a decision. All this results in a delayed 'knowing that the rotor is there'. This gives overshoot in position (a delayed stop, not so much due to the mechanics but due to the ADC & SW).
Henk
Items to consider next to straight degrees2voltage conversion:
- overshoot (when you stop, the rotor actually moved still a tiny bit)
Henk, PA3GUO http://www.qsl.net/pa3guo
I got an idea.
At the moment, most systems have some sort of PC sending data to a controller which makes decisions.
1. Antenna pot goes to A/D on PIC 2. PIC is told from com port where it should be 3. PIC makes up its mind to turn left or right. 4. Relays are part of controller.
I have another way to do it.
1. PIC chip reads position of POT etc from A/D and SENDS position to LINUX box on RS232 2. PERL asks PREDICT where the sat should be 3. PERL works out what to do 4. Turn on relays using an inexpensive relay board on the parrallel port.
What about the old games port ?
That used to read pots ?
---------------------------------------------------------------------------- Andrew Rich VK4TEC
I just looked at my multimeter - it has rs232 - cheap and easy interface for a rotator.
Just hook the leads up, it even has a display !
---------------------------------------------------------------------------- Andrew Rich VK4TEC vk4tec@people.net.au mailto:vk4tec@people.net.au http://www.tech-software.net
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org]On Behalf Of Andrew Rich Sent: Monday, 31 December 2007 8:51 PM To: Henk, PA3GUO; amsat-bb@amsat.org Subject: [SPAM] [amsat-bb] Re: Making your own rotator controller
I got an idea.
At the moment, most systems have some sort of PC sending data to a controller which makes decisions.
1. Antenna pot goes to A/D on PIC 2. PIC is told from com port where it should be 3. PIC makes up its mind to turn left or right. 4. Relays are part of controller.
I have another way to do it.
1. PIC chip reads position of POT etc from A/D and SENDS position to LINUX box on RS232 2. PERL asks PREDICT where the sat should be 3. PERL works out what to do 4. Turn on relays using an inexpensive relay board on the parrallel port.
What about the old games port ?
That used to read pots ?
---------------------------------------------------------------------------- Andrew Rich 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
Hi Andrew
As well as sending commands to the rotator controller, most prediction software also polls the rotator controller for some indication of feedback for the user, and sometimes it is also used to detect stalling (protecting you, for example, in the nightmare scenario whereyour rotator wraps itself up in the feeder).
BTW, I've heard the LVB tracker is very good ;-) and the v0.8 firmware works with Predict.
In the LVB tracker I average sixteen or so ADC samples over time to get some kind of sensible value. Either that or I could pop a 10uF cap on the Az/El PIC ADC inputs, but software was cheaper.
73, Howard G6LVB
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Andrew Rich Sent: 31 December 2007 10:51 To: Henk, PA3GUO; amsat-bb@amsat.org Subject: [amsat-bb] Re: Making your own rotator controller
I got an idea.
At the moment, most systems have some sort of PC sending data to a controller which makes decisions.
1. Antenna pot goes to A/D on PIC 2. PIC is told from com port where it should be 3. PIC makes up its mind to turn left or right. 4. Relays are part of controller.
I have another way to do it.
1. PIC chip reads position of POT etc from A/D and SENDS position to LINUX box on RS232 2. PERL asks PREDICT where the sat should be 3. PERL works out what to do 4. Turn on relays using an inexpensive relay board on the parrallel port.
What about the old games port ?
That used to read pots ?
---------------------------------------------------------------------------- Andrew Rich 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
Is there a one stop shop for the LVB ?
---------------------------------------------------------------------------- Andrew Rich VK4TEC vk4tec@people.net.au mailto:vk4tec@people.net.au http://www.tech-software.net
-----Original Message----- From: Howard Long [mailto:howard@howardlong.com] Sent: Monday, 31 December 2007 11:13 PM To: vk4tec@people.net.au; 'Henk, PA3GUO'; amsat-bb@amsat.org Subject: [SPAM] RE: [amsat-bb] Re: Making your own rotator controller Importance: Low
Hi Andrew
As well as sending commands to the rotator controller, most prediction software also polls the rotator controller for some indication of feedback for the user, and sometimes it is also used to detect stalling (protecting you, for example, in the nightmare scenario whereyour rotator wraps itself up in the feeder).
BTW, I've heard the LVB tracker is very good ;-) and the v0.8 firmware works with Predict.
In the LVB tracker I average sixteen or so ADC samples over time to get some kind of sensible value. Either that or I could pop a 10uF cap on the Az/El PIC ADC inputs, but software was cheaper.
73, Howard G6LVB
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Andrew Rich Sent: 31 December 2007 10:51 To: Henk, PA3GUO; amsat-bb@amsat.org Subject: [amsat-bb] Re: Making your own rotator controller
I got an idea.
At the moment, most systems have some sort of PC sending data to a controller which makes decisions.
1. Antenna pot goes to A/D on PIC 2. PIC is told from com port where it should be 3. PIC makes up its mind to turn left or right. 4. Relays are part of controller.
I have another way to do it.
1. PIC chip reads position of POT etc from A/D and SENDS position to LINUX box on RS232 2. PERL asks PREDICT where the sat should be 3. PERL works out what to do 4. Turn on relays using an inexpensive relay board on the parrallel port.
What about the old games port ?
That used to read pots ?
---------------------------------------------------------------------------- Andrew Rich 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
Hi Andrew
Is there a one stop shop for the LVB ?
AMSAT-UK sells worldwide: bare boards for the tracker and USB option, as well as a complete kit of parts but without a box.
AMSAT-NA sells a number of different options, all the way up to a completely built unit in a rather slick looking box.
I have been very surprised by the regular requests for completely built units, as well as the kits of parts. One of my design criteria was to use easily available parts (many in the average ham's stock), but the convenience of a kit has been very popular, as have the completely built units. I was blown away by the popularity of the boards at Dayton this year, and yet again at the Symposium where Gould announced the ready-built units.
I'm old fashioned I guess! I hand wired four or five on perf board before doing the PCB. FWIW I estimate there are now 650 boards out there. Not sure how many are actually built and how many are on the "things to do" pile! Judging by the number of enquiries I get, I am sure plenty are built.
One final thing, the 0.8a firmware (needed to ignore the NUL characters generated by Predict) is at http://www.g6lvb.com/Articles/LVBTracker/LVBTrackV0_8a.hex. I've yet to put a link to this on my website.
Cheers, Howard
I just looked on the AMSAT WEB site... All I see is the PCB & the box. Did I miss some thing??
Will WC2L
----- Original Message ----- From: "Howard Long" howard@howardlong.com To: vk4tec@people.net.au; "'Henk, PA3GUO'" hamoen@iae.nl; amsat-bb@amsat.org Sent: Monday, December 31, 2007 9:44 AM Subject: [amsat-bb] Re: [SPAM] RE: Re: Making your own rotator controller
Hi Andrew
Is there a one stop shop for the LVB ?
AMSAT-UK sells worldwide: bare boards for the tracker and USB option, as well as a complete kit of parts but without a box.
AMSAT-NA sells a number of different options, all the way up to a completely built unit in a rather slick looking box.
I have been very surprised by the regular requests for completely built units, as well as the kits of parts. One of my design criteria was to use easily available parts (many in the average ham's stock), but the convenience of a kit has been very popular, as have the completely built units. I was blown away by the popularity of the boards at Dayton this year, and yet again at the Symposium where Gould announced the ready-built units.
I'm old fashioned I guess! I hand wired four or five on perf board before doing the PCB. FWIW I estimate there are now 650 boards out there. Not sure how many are actually built and how many are on the "things to do" pile! Judging by the number of enquiries I get, I am sure plenty are built.
One final thing, the 0.8a firmware (needed to ignore the NUL characters generated by Predict) is at http://www.g6lvb.com/Articles/LVBTracker/LVBTrackV0_8a.hex. I've yet to put a link to this on my website.
Cheers, Howard
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
It also comes with a CD that has the parts list on it. You're kinda on-your-own to gather up the parts. Jim KQ6EA
--- William Liporace - NA2NA will-na2na@nycap.rr.com wrote:
I just looked on the AMSAT WEB site... All I see is the PCB & the box. Did I miss some thing??
Will WC2L
----- Original Message ----- From: "Howard Long" howard@howardlong.com To: vk4tec@people.net.au; "'Henk, PA3GUO'" hamoen@iae.nl; amsat-bb@amsat.org Sent: Monday, December 31, 2007 9:44 AM Subject: [amsat-bb] Re: [SPAM] RE: Re: Making your own rotator controller
Hi Andrew
Is there a one stop shop for the LVB ?
AMSAT-UK sells worldwide: bare boards for the
tracker and USB option, as
well as a complete kit of parts but without a box.
AMSAT-NA sells a number of different options, all
the way up to a
completely built unit in a rather slick looking box.
I have been very surprised by the regular requests
for completely built
units, as well as the kits of parts. One of my
design criteria was to use
easily available parts (many in the average ham's
stock), but the
convenience of a kit has been very popular, as
have the completely built
units. I was blown away by the popularity of the
boards at Dayton this
year, and yet again at the Symposium where Gould
announced the ready-built
units.
I'm old fashioned I guess! I hand wired four or
five on perf board before
doing the PCB. FWIW I estimate there are now 650
boards out there. Not
sure how many are actually built and how many are on
the "things to do" pile!
Judging by the number of enquiries I get, I am
sure plenty are built.
One final thing, the 0.8a firmware (needed to
ignore the NUL characters
generated by Predict) is at
http://www.g6lvb.com/Articles/LVBTracker/LVBTrackV0_8a.hex.
I've yet to
put a link to this on my website.
Cheers, Howard
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
The parts list and other documentation for the LVB Tracker has moved to my website, so we can keep updated information available and not bother with making CDs.
Check out http://www.LVBTracker.com
73, Gould, WA4SXM ----- Original Message ----- From: "Jim Jerzycke" kq6ea@pacbell.net To: "William Liporace - NA2NA" will-na2na@nycap.rr.com; amsat-bb@amsat.org Sent: Monday, December 31, 2007 1:15 PM Subject: [amsat-bb] Re: [SPAM] RE: Re: Making your own rotator controller
It also comes with a CD that has the parts list on it. You're kinda on-your-own to gather up the parts. Jim KQ6EA
--- William Liporace - NA2NA will-na2na@nycap.rr.com wrote:
I just looked on the AMSAT WEB site... All I see is the PCB & the box. Did I miss some thing??
Will WC2L
----- Original Message ----- From: "Howard Long" howard@howardlong.com To: vk4tec@people.net.au; "'Henk, PA3GUO'" hamoen@iae.nl; amsat-bb@amsat.org Sent: Monday, December 31, 2007 9:44 AM Subject: [amsat-bb] Re: [SPAM] RE: Re: Making your own rotator controller
Hi Andrew
Is there a one stop shop for the LVB ?
AMSAT-UK sells worldwide: bare boards for the
tracker and USB option, as
well as a complete kit of parts but without a box.
AMSAT-NA sells a number of different options, all
the way up to a
completely built unit in a rather slick looking box.
I have been very surprised by the regular requests
for completely built
units, as well as the kits of parts. One of my
design criteria was to use
easily available parts (many in the average ham's
stock), but the
convenience of a kit has been very popular, as
have the completely built
units. I was blown away by the popularity of the
boards at Dayton this
year, and yet again at the Symposium where Gould
announced the ready-built
units.
I'm old fashioned I guess! I hand wired four or
five on perf board before
doing the PCB. FWIW I estimate there are now 650
boards out there. Not
sure how many are actually built and how many are on
the "things to do" pile!
Judging by the number of enquiries I get, I am
sure plenty are built.
One final thing, the 0.8a firmware (needed to
ignore the NUL characters
generated by Predict) is at
http://www.g6lvb.com/Articles/LVBTracker/LVBTrackV0_8a.hex.
I've yet to
put a link to this on my website.
Cheers, Howard
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
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
Gould Smith wrote:
The parts list and other documentation for the LVB Tracker has moved to my website, so we can keep updated information available and not bother with making CDs.
Check out http://www.LVBTracker.com
73, Gould, WA4SXM
Gould,
Is there a possibility Amsat will offer the parts separately for those of who purchased the PCBs but have not gotten around to sourcing the parts?
Best wishes for the New Year! John Meeks KC8ZFN
I did something with an OLIMEX board a while back.
The lot is there, program header, RS232, development area.
Is there much difference between and 16F877 and 16F876 ?
http://www.dontronics-shop.com/PIC-P40-ICSP-ICD-enabled-40-PIN-PIC-microcont roller-prototype-board-p-16527.html
---------------------------------------------------------------------------- Andrew Rich VK4TEC
Not much differnece except extra pins, although beware that the crystal I use is 4MHz and that the in circuit programmer tool I wrote will only write to '876's and '876A's as it does a chip ID check.
You can still load the .hex file into MPLAB and use any other compatible programmer you like. Beware that back when I wrote the original programmer I didn't know how to set config bits in the hex file (ISTR that you couldn't way back then) so my ICP hacks the config bits. Once you import the .hex file into MPLAB you will need to set the config bits yourself.
From PicProg.c...
// Default config bits... // Osc=XT, WDT off, PUT on, BOD off, LVP off, FPW on, DBG off, data EE prot off, CodeProt off au16Data[0x2007]=0x3F31;
Howard
-----Original Message----- From: Andrew Rich [mailto:vk4tec@people.net.au] Sent: 01 January 2008 00:24 To: Howard Long; 'Henk, PA3GUO'; amsat-bb@amsat.org Subject: Re: Making your own rotator controller
I did something with an OLIMEX board a while back.
The lot is there, program header, RS232, development area.
Is there much difference between and 16F877 and 16F876 ?
http://www.dontronics-shop.com/PIC-P40-ICSP-ICD-enabled-40-PIN-PIC-microcont roller-prototype-board-p-16527.html
---------------------------------------------------------------------------- Andrew Rich VK4TEC
After reading the preceding thread, I thought I would pose a question to the list:
Does anyone know of a rotator interface for controlling selsyn motors? I have a dish that uses them for az and el drives. They seem to take +/-10 volts to position the dish. Dish position is determined from digital angle encoders (gray code). Unfortunately when I obtained the dish, I did not get the pointing software. It is complete with computer controller that talks via RS-232 with a computer running the tracking program. The company that built the dish is long out of business so no luck on getting schematics or software. These were custom built (only ten made).
73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep dubususa@hotmail.com ======================================
----- Original Message ----- From: "Edward Cole" kl7uw@acsalaska.net To: "Howard Long" howard@howardlong.com; vk4tec@people.net.au; "'Henk, PA3GUO'" hamoen@iae.nl; amsat-bb@amsat.org Sent: Tuesday, January 01, 2008 7:55 PM Subject: [amsat-bb] Re: [SPAM] RE: Re: Making your own rotator controller
Does anyone know of a rotator interface for controlling selsyn motors?
73, Ed - KL7UW
Hi Ed, KL7UW
Unfortunately I know only how to use selsyn motors as position indicators. I use selsyn motors instead of potentiometers only as precise position indicators to show the angular position of AZ and EL in the shak for my 2400 MHz dish. The shaft of the antenna is mechanically coupled with the shaft of a transmitter selsyn motor with a ratio 1/1 while another receiver selsyn motor is in the shak and has a mechanical index in the shaft to show the angular position. Both selsyn motors transmitter and receiver are supplied in parallel with AC voltage R1-R2 for the rotors and S1-S2-S3 for the stators.
If I need a digital indication instead of a mechanical index indication then the Analog Device AD2S80A series of variable syncro/resolver-to -digital converters is the chip to be used. In addition this chip has a DC output that supply a linear 0-5 volt DC for a 0 to 360° digital indication and this voltage can be used as feedback with any available tracking program for automatic traking.
73" de
i8CVS Domenico
Yes !
Now I remember I also needed to implement this (but <16). I have done this inside the ST6, as sending via rs232 also took time.
A capacitor would have had my preference, but I never thought about that. Good suggestion.
We are getting to a complete overview here ! (too bad I did not properly document this back then ...)
Henk
In the LVB tracker I average sixteen or so ADC samples over time to get some kind of sensible value. Either that or I could pop a 10uF cap on the Az/El PIC ADC inputs, but software was cheaper.
73, Howard G6LVB
participants (9)
-
Andrew Rich -
Edward Cole -
Gould Smith -
Henk, PA3GUO -
Howard Long -
i8cvs -
Jim Jerzycke -
John Meeks -
William Liporace - NA2NA