A Smart Controller for the AR-22 Rotator by WA2FZW Version 5.4
The AR-22 rotator controller is an Arduino Uno based controller for the old CDE AR-22 antenna rotator which replaces the clunk-clunk controller that the original used.
The main features include the ability to turn the antenna in 1, 5 or 10 degree increments and the ability to control it with many of the rotator control programs available such as the N1MM Rotor program.
The files provided here include the latest version of the software, a manual describing how to build and use the controller and the Gerber files needed to fabricate the 2 custom PCBs used.
Version 5.3
No changes to the software (Version 5.2 is the latest software version), but Neal (WA9WYI) discovered a mistake on the power supply PCB; the pins on the LM7812 regulator were reversed. The Gerber files for the power supply PCB are corrected and identified as Version 5.3.
Document Update 9/4/2020:
Added information about the commands available on the serial interface. Not sure why I never listed them in the original!
Update Jan 04, 2021 - Fixed a couple of typos in the docmentation and added a "Table of Contents".
Version 5.4 - 2/24/2021
I made a number of changes to both the hardware and software and finally fixed a problem that has been bugging me since the intial version!
Hardware Changes
In the hardware, I added more filtering on the power supply board and on the controller board I added snubbing diodes across the relay coils (I thought they were built into the relays; NOT) and added a bypass capacitor in an effort to reduce the noise on the rotator pulse line.
One additional change on the controller PCB was to add a header connected to the TX2/RX2 serial interface on the Arduino Mega. This is not used yet, but I plan to add elevation control using a separate processor.
Software Changes
In the software, I made some changes to the timeout logic to deal with two problems.
One problem this solves is the fact that there is some inertial delay when the rotator initially turns on; the bigger the antenna, the more inertia! The second problem was that sometimes the rotator was stopping with the cam switch in the closed position which caused an immediate pulse upon the next startup and the inertia delay was causing an immediate timeout.
Now when the rotator starts (or reverses direction), the cam pulse timeout value is set to 2 seconds by the symbol INITIAL_TIMEOUT in the header file. Once the controller has seen 2 cam pulses, the timeout value reverts to the value of ROTATOR_TIMEOUT.
I also made a few changes in the code to improve performance and I added the hooks for an interface to an elevation controller for my satellite antenna.
Note that the Version 5.4 software will run on the older hardware (Version 5.2 and later).