EME - Antenna - Control - System: new version
|Short description of the features||
The system is based on a 89C51ED2 Microcontroller
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:
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.
Andy Talbot, G4NJT, kindly developed hardware and firmware to interface a GPS module to the controller.
|-||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|
with different absolute encoders is possible: 10..12bit
A2-S-S, MAB25, ....
|-||Selectable stepsize for tracking|
|-||Selectable offset for azimuth and elev. up to +/- 9.9 deg|
|-||Motor control output clw/ccw up/down|
operation by 4 buttons at controller, non volatile storage of all
( remote operation by PC is possible)
|-||Real - Time - Clock|
|-||4 x 20 character LCD - display|
PC is not necessary for controlling (no interference!), single wire line from antenna (encoders) into shack, ready within a few seconds
HEX - FILE FOR CONTROLLER :
See a step by step guide how to upload the firmware, written by HB9DRI: AN02.pdf
23Nov12: Doppler shift indication for 3.4GHz and 24GHz included, remote commands for antenna offset compensation added
20Oct12: new style of offset compensation included and interference from PWM to encoder reading fixed. Read the additional documentation, written by HB9DRI: AN03.pdf
5Sept11: improved readout for MAB28 encoder. (jumping of last digit avoided)
12Oct10: display of actual antenna position instead of encoder position possible. See details in the DOC, page5. eme_contr_jfl_v51.hex
better stability of readout with the MAB25 and
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
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.
Alex has written an additional very useful documentation how to test, install and interface the system to the antenna.
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