A List of Version Changes

September 2009 - Version 9.03

Added a hardware clock.

20 October 2008 - Version 8.00

Added support for the SCA61T inclinometer chip. Because of size constraints of the 18F4620 (64K memory) I have had to move to a larger memory chip a 18F4682 (80K memory). I was then able to restore some earlier code involving improved calculation of nutation for the moon and restore my best calculation of doppler taking into account the changing distance of the moon from earth. The 18F4682 (or the 18F4685) fit in the same socket with identical pinouts.

Version 7.02 in a 18F4620 or the 18F4680 is a very usable solution, but for those who would like to use an inclinometer chip for ease of mounting on the antenna then Version 8.00 is the solution. I have renumbered the menu items from 27 onward to allow for an additional menu item "SCA61T calibrate". See the revised manual.

5 September 2008 - version 7.02

Added GPS entry of data, accessed by connecting a GPS to the DB25 computer interface. The time/date/lat/long are entered automatically on application of power providing the "up" button is held in for 1 second. The opening screen will wait for information from the GPS indicating it has acquired sufficient satellites. The menu access is simplified by changing the Park function to a menu item and renaming the switch as "Menu". Doppler calculations are made and displayed subject to setting the correct band in a menu item. The brake operation has been modified and the operation of ModeB relay wiring has been altered to reduce the chance of a 'relay race' situation causing a short across the contacts (there is now a minimum pause of 200msec when changing direction even if Delay is set at 0)

18 April 2008 - version 6.00

Added facility for 14 bit and 16 bit inputs from the AZ/EL unit and wrote some code to interface to 2 of 74HC165 chips connected to a 16 bit Gray coded device. Tidied up several of the menus to make them more user friendly. Used a new version of the compiler that now puts a 0 in front of numbers less than one (0.12 instead of .12) on the LCD display and the compiler also supports faster hardware multiplies to speed the extensive maths in this program. I have allowed another decimal point in the display for the antenna locations but only access this greater accuracy when using 14 or 16 bit encoders. Otherwise the number is rounded to one decimal point and a 0 inserted at the second place.

29 February 2008 - version 5.90 (didn't release V5.80)

Added refraction into computations for moon and sun. Improves accuracy for near horizon - may be turned off if required.
Added capability to switch relay methods from my double action approach (mode A) to a more standard four relay function (mode B) with one task for each relay.
Enabled the Calibrate switch to permit matching a beam heading to a computed object. Very useful for that final adjustment.

20 January 2008 - version 5.70

Added SEI interface capabilities

30 October 2007 - version 5.62

Minor changes to send button directions and park information to the VGA interface system

12 October 2007 added the capability to use the US Digital MA3-P12 rotary encoder module - AUS$40

The HEX code is available - see above for AZ/EL unit PIC's code and manual

30 July 2007 Added a Version 5.61 shack unit hex file compiled for the PIC18F4680.

The PIC18F4680 is easier to obtain in Australia than the PIC18F4620. I have provided a hex file for the shack unit that works successfully with the PIC18F4680

June 2007 Version 5.61

An annoying bug found. When running from a pot, the spread did not calulate properly. Version 5.61 fixes that. If you don't want to burn the PIC again just increase the spread number to get the result you want. The documentation version 5.60 remains accurate.

May 2007 Version 5.60 (development will now stop unless someone finds a bug)

This is the working software to interface with Doug VK3UM's EME Planner. Document files updated to Version 5.60, shack unit hex software for the 18F4620.
Download VK3UM's EME Planner (Version 16 May 2007)
Updates for all Doug's programs are available from: Peter sm2cew at http://www.sm2cew.com and Darrell ve1alq at http://www.ve1alq.com/downloads/software/vk3um.htm
Orbitron (an excellent satellite tracking program) can be found on Sebastian Stoff's website: http://www.stoff.pl/

25 April 2007 Version 5.40

The shack unit can now be directly controlled by Doug VK3UM's program. In addition I have added a capacity to set the UTC clock in the shack unit by clicking a button on the Orbitron interface or automatically in the EME Planner. The Orbitron interface also now shows the beam headings for general information.

14 April 2007 Version 5.20

Under some circumstances there was a reluctance for the computer to interface successfully. This version has a fixed Orbitron interface for installation on the computer. I'm pleased with its operation.

I also added in the document file some optional modifications to overcome possible interface issues when connecting to the computer or the VGA interface system.

In the unlikely occurrence that your computer needs RS232 levels on CTS and DTR the Version 5.20 document file covers this. Also the latest version of the 'Shack software' allows for the inversion caused by putting the MAX232 in circuit for CTS and DTR by adding command (32).

This version supports satellite calculations from Orbitron and the essentials to interface to Doug VK3UMs EME tracker, Doug will be doing the interface shortly. I will be freighting over a beam system early next week for testing purposes.

Note that for most applications the accuracy of the internal sun/moon calculations is quite satisfactory and no connection to an external computer is needed.

18 February 2007 Version 5.00

There was a bug in the software stops for south based rotators. This is fixed. Manual updated.

Added facility for VGA monitor. This will require an external unit from Dontronics. See their web page at:

http://www.dontronics-shop.com/product.php?productid=16145&cat=262&page=1

and an additional 16F628 or 16F648 interface PIC to be described once I have it working as I want. The shack unit now supports an additional software switch VGA OFF/ON.

The switch on display also indicates Version Number to assist users with updates.

I have been having trouble receiving some emails. Please persevere, I always reply to every query.

15 January 2007 Version 4.9
(Screwjacks now catered for)

Updated 15 Jan 2007

New developments finished and tested. A version of the AZ/EL code has been written for use on screwjack solutions. The screwjack outputs a count, this, when combined with a direction switch, provides a substitute for the number coming out of what would normally be an AS5045. In the shack unit I have added software stops in case your dish is about to take the top off the chimney and I have enabled offsets in both a negative and positive direction and dis. The serial inputs (such as those from an AS5040/45 or screwjack) may also now scale the incoming numbers as is currently possible with the potentiometer input. So if you want to cover just a small part of the sky you could introduce a mechanical multiplier at the antenna for improved accuracy. A 4:1 gearing system could result in a guaranteed better than 0.1 accuracy.

I've also found a small error in my maths and the accuracy of output seems to have improved modestly for Version 4.9. Mostly you can assume that the moon calculation is within 0.1 degree, sun is better.

I have rewritten the main manual and provided a separate manual for the screwjack. Screwjack manual download.

26 December 2006 update

I've been experimenting with a screwjack system for dish control with Charlie VK3NX. I now have software that supports his screwjack system (e.g. a max count of 1628 over 100 degrees in the elevation). The system uses the usual shack unit system and uses the existing AZ/EL board to interface between the shack unit and the screwjack system. It includes features of :

It uses an error table to fine tune the readings in the 16F628. The table is user adjusted in the eedata at burn time. I have written a short 'manual'. This is included in the download for 15 January 2007.

12 December 2006 update for shack code Version 4.3

Three additions - see modified document file

28 November 2006 update for version 4.2

To reduce confusion and improve versatility I have included support for both the AS5040 (10 bit) and AS5045 (12 bit) in the one Shack Unit hex file (Shack42Unit.hex) now at version 4.2. I also added a facility to turn ON/OFF the averaging in the shack unit.

With menu control in the one HEX file for the Shack Unit as well as simplifying the burn process it also means that if you want, one port can be set for an AS5040 and the other for AS5045. I'm not sure why you would want to do this, but it is possible.

Unfortunately different HEX files for AS5040 or AS5045 are still required for the AZ/EL units because a menu system is not available to enable easy user switching.

If you plan to use a potentiometer and you have already downloaded and burned the OLD hex file (Shack5045unit.hex), please note this had a bug and would not have permitted the full range for a potentiometer. This problem is corrected in the new version. Each of the old shack unit files would be perfectly satisfactory if you plan to use a pair of AS5040s or a pair of AS5045s only, although without the option to change resolution or prevent averaging.

I have upgraded the document file for the project and described the new menu items.

12 November 2006 notes

All boards are now back on stream. The fixed encoder boards have arrived and been distributed to those who had bought the set previously.

The boards are sold as a set of 5 boards - 1 of Shack unit, 2 of antenna AZ/EL units, two of AS5040/5045 boards. An extra two AZ/EL interface boards of an earlier working version will be tossed in if you would like them - the manufacturer accidentally made my 'quote set of AZ/EL boards' and not the set I sent with the order. He's re-made these and I now have complete sets, the major difference being that the new set have provision for mounting back to back with the encoder board and have an extra trace to use the US Digital MA2 magnetic encoder when I write the code for it.

The hardware caters for either a AS5040 (10 bit) or AS5045 (12 bit) encoder chip. The software has now been written for the AS5045. Thanks Jerry W7QX and Michael Jeffery for the AS5045s that enabled me to do this. Note the different downloads depending on which chip is used below (only the AZ/EL units now - see above). The magnet calibration modes behave differently in the two chips. The AS5040 remains in magnet calibration mode after SW3 is closed and then opened, until power is removed. The AS5045 has a different programming sequence and can be taken out of programming mode by software. When using the calibration mode with the AS5045 leave the switch in the closed position during calibration, opening SW3 switch returns the system to normal operation.

Where I write AS5040 in my descriptions you can mentally substitute AS5045. The two chips are very similar although there are some pinout differences that do not affect this project, the main difference is the AS5040 is a 10 bit device (1024 positions) while the AS5045 is a 12 bit device (4096 positions). If buying chips I would buy the AS5045 device every time, they are about the same price, but I have a number of AS5040 chips on hand and they are MORE than adequate for most situations. Few of us have antennas with beam widths of better than 10 degrees, let alone 0.5 degree.