Rotator Controller

Rotator Controller - Software and Firmware

Control Software

Using the ZL1BPU NATIVE PROTOCOL, it would be quite straightforward to develop PC DOS, LINUX or WINDOWS software to control the rotator. A simple DOS application ARC_1.EXE is illustrated to the right. It has a status window to the left (colour bar), status in text, and a bar graph heading display. As the heading changes, the pointer moves, and the pointer colour also follows the status. The little arrow indicates the requested heading. This software will operate in a WINDOWS DOS box.

There are six heading function keys which are user programmable. The name is programmable along with the heading. For example, the function key F4 in the picture sends the rotator to point to Europe, Long Path. There are function keys for direct heading entry and immediate stop.

The Windows software is similar, but features a slider for direct heading command entry, a "favourites" list, and even a database of country prefixes - select the prefix, and away goes the rotator!

The controller also operates with existing software such as MIXW, DX4WIN, YPLOG, and WriteLOG.

PC software should have the ability to operate with North-centred and South centred rotators. The difference in effect is that the North-centred type accepts commands -180 to 180 or 181 to 360 interpreted as -180 to 0. South-centred rotators only need accept commands from 0 to 360. In both cases the feedback from the controller, and commands to the controller, are in the same range, near zero for fully anti-clockwise, and near 255 for fully clockwise. Zero offset and gain factors are used in the PC to translate from controller values to real headings in degrees, and vice-versa.

In addition to issuing the commands, and interpreting the heading and status, the PC software should also interpret the command responses. The "G" command response is in the same format as the status messages, and can optionally be used to indicate the demand heading automatically just before the rotator starts to move. Thanks to the micro controller firmware, this happens automatically and is a nice touch. If up/down buttons are used to set the demand heading in the PC application, these could also be illustrated on the heading display.

The "S" command can be used to poll the rotator control about every two seconds while the rotator is idle, in order to learn the current heading. There is no need to poll the controller while the antenna is rotating, as position commands are transmitted automatically.

Embedded Firmware

The firmware as supplied is not intended for use with antenna tracking software for applications such as satellite tracking. It would be quite practical to provide the unit with suitable firmware, but in general this type of rotator lacks sufficient positioning accuracy.

This firmware supports the full ZL1BPU "KISS" type protocol, and the ORION, SARTEK and YAESU position commands. The YAESU "W xxx yyy" command and the HYGAIN "A" and "E" commands used for Azimuth/Elevation rotators are NOT supported, nor is the M2 command set.

The following software and firmware is available. Note the FREE OFFER:
Zipped archive containing AVR assembled executable in Intel format, and DOS executable.
Available from the author. Source code is also available.
Zipped archive containing PC executable and setup file. Operates in DOS, under Win 3.1, or in a DOS BOX from Win95/98 etc.
Available from the author. Source code also available.
A free copy of the software and firmware executables will be sent by email to any NZART member (will be sent only to [email protected] email addresses).

To anyone else the cost for executable code (embedded and PC) is $10, posted to the address below. Executables will be delivered by email on receipt of payment. Reasonable email support is included in the price.

Murray Greenman ZL1BPU
13 Totara Street,
Waiuku 2123,
The above software only operates with the ZL1BPU Rotator Controller. The rotconx firmware and ARC_x.EXE DOS executable software are © Copyright M. Greenman 2003. The software remains the property of the copyright holder. You may use this firmware/software for private applications, but may not distribute any of the information in the archive without my permission if it has been modified in any way. You may distribute the original archive freely at no charge to the recipient, but no support is provided without registration.

Copyright Murray Greenman 1997-2005. All rights reserved. Contact the author before using any of this material.