| Short description of the features |
The system is based on a 89C51ED2 Microcontroller |
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Computation of position (without PC) of moon,sun,Cygnus,Sagittarius,Cassiopeia,Taurus,Leo and Aquarius |
Demo - Version of the controller system
Digital position encoders you can get from http://www.usdigital.com . Look for the type A2-S-S, it has 0.1deg resolution and interfaces well to my system. A cheaper but probably less accurate solution is the MAB25 from Megatron with also 0.1deg resolution: Sometimes there is an unstable readout when connecting the MAB25 via a low quality cable. See hints for improvement at: AN01.pdf Although the use of incremental encoders is not recommended, I programmed a 89C52 for converting the pulses to the SSI protocol. Get the firmware for it here: inc_ssi.hex See the circuit diagram in the controller documentation. NEW: Andy Talbot, G4NJT, kindly developed hardware and firmware to interface a GPS module to the controller. You can download : description (PDF) , HEX file: GPS firmware and PCB BRD file: GPS interface PCB |
| - | Azimuth and elevation motor controlling for all targets plus two free choice positions | |
| - | Transmission of antenna position via LAN cable from antenna down to the controller in the shack | |
| - | Interfacing
with different absolute encoders is possible: 10..12bit
A2-S-S, MAB25, .... |
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| - | Selectable stepsize for tracking | |
| - | Selectable offset for azimuth and elev. up to +/- 9.9 deg | |
| - | Motor control output clw/ccw up/down | |
| - | Local
operation by 4 buttons at controller, non volatile storage of all
parameters
( remote operation by PC is possible) |
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| - | Real - Time - Clock | |
| - | 4 x 20 character LCD - display | |
| Main
advantages:
PC is not necessary for controlling (no interference!), single wire line from antenna (encoders) into shack, ready within a few seconds |
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HEX - FILE FOR CONTROLLER : See a step by step guide how to upload the firmware, written by HB9DRI: AN02.pdf 5Sept11: improved readout for MAB28 encoder. (jumping of last digit avoided) 12Oct10: display of actual antenna position instead of encoder position is possible. See details in the DOC, page5. (If you are not sure how to use v51, take v41.) 12Sept10: better stability of readout with the MAB25 and MAB28 encoders. 5Aug10: improvements for testing the remote commands with a terminal program. 27Nov09: inverse indication of azimut is possible, necessary if the axis of the encoder is looking downwards. See details in the DOC, page 5. eme_contr_jfl_v21.hex 17Nov.09: for using the controller in southern hemisphere: 1.)bug showing up in setup fixed 2.)antenna moving now smoothly via north eme_contr_jfl_v11.hex June09: eme_contr_jfl_v10.hex BRD - FILES FOR PCBs : DOC FILE WITH DETAILED DESCRIPTION: VIDEO OF THE CONTROLLER WORKING: A model of a parabolic dish is controlled by the system. There is no difference for the interface board if DC motors with 5W or 50W are connected. Maybe some heatsink is needed for the motor drivers at higher power.
AVAILABILITY OF CONTROLLER MODULES / PCBs I will not provide myself
PCBs or completely built modules, but kindly HB9DRI
(member of HB9Q group) will do so. hb9dri(at)emeham(dot)com
Alex has written an additional very useful documentation how to test, install and interface the system to the antenna. |
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