Orbitron & PST Rotator Interface with Easy Rotor Control

This blog is an update of this – Pan & Tilt Orbitron Interface post as I’ve added some pictures of the kit used and I have finally got round to putting the Rotorcards in a decent enclosure.

The main controller is a ERC-M USB kit which interfaces with the PC and programs which are running , the Rotorcard relays  are controlled by the ERC-M, the Rotorcard also provides a positional feedback to the ERC-M.

Front panel of the Desktop housing for the ERC-M, the front panel has manual buttons for up/down tilt & left/right pan, LED's also show when internal relays are operated.

Front panel of the Desktop housing for the ERC-M, the front panel has manual buttons for up/down tilt & left/right pan, LED’s also show when a signal is sent to the Rotorcard relays.

The two yellow LEDs on the left hand side indicate the signal to the auxiliary relay.

The LCD display is showing the position in degrees, the number after Az or El is the feedback from the Pan & Tilt head, the numbers on the other side of the > are the output from the software, the ERC-M compares the two values and energises the appropriate relays which in turn operate the motors in order to keep the values aligned.2016-04-01 12.04.05 (Medium)

The ERC-M kit is the top left PCB, the desktop housing is also a kit comprising of the LCD display and front panel buttons.

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The PCB mounted inside the desktop housing is the 13.8v to 10v voltage regulator which provides a stabilized supply to the Pan & Tilt heads positional potentiometers.

An external 13.8v supply is required in order to drive the high current motors of the Pan & Tilt head.

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The two Rotorcards (one for Pan the other Tilt, or more correctly Azimuth and Elevation respectively) are enclosed, 13.8v can be fed to the relays here or at the desktop housing.

2016-04-01 12.01.25 (Medium)The three outputs from the ERC-M enter on the right hand side to the Rotorcards, the middle connector is the 13.8v – 0v – 10v supply.

The top Rotorcard relays operate for clockwise or anticlockwise supply to the Azimuth motor, the third relay is not used (auxiliary relay) as the Pan & Tilt head does not have an electro-mechanical brake fitted, if it did, relay three would operate in advance of the motor supply relays.

The bottom Rotorcard is for elevation, Up & Down.

On my version, the ERC-M is connected to a PC via a USB connection to Com Port 6, the position of the heads has already been calibrated using the provided software from Easy Rotor Control.

To start tracking satellites, the first step is to open Orbitron.

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This is a free download program, each time it is ran, check that the TLE files have been updated then select the satellite of interest from the right hand list, once this is done, click on the satellites on screen icon.

On the bottom tabs, select rotator and click DDE a small box should now open on the screen with live positional data of the selected satellite showing,  (a separate download is needed for the DDE function).

Open PST Rotator program:

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Using the PST Rotator settings configure the program to respond to Comm Port 6, use Orbitron as the controlling program, that the type of head ouput is GS-232 and Az/El is selected.

When the program is set to ‘Track’ as the above image, the displays show the actual position of the Pan & Tilt head by a black line with the green line showing where the head needs to move to, the green line is controlled via DDE from Orbitron.

A further setting I have enable is the link to weather information, this allows the mast to rotate into the wind when a trigger speed has been reached, this reduces wind loading on the mast and antenna.

2016-04-01 11.36.20 (Medium)This is a Dennard CCTV Pan & Tilt head and operates at 24v, 13.8v works it just fine with a maximum current draw of 600mA, I have commoned the potetiometers supply, so the minimum number or wire cores is 8:

2 – Pan Motor

2 – Tilt Motor

2 – 10v supply across positional potentiometers

1 – Signal feedback from Pan

1 – Signal feedback from Tilt

The next stage is to get some decent antennas for satellite reception.

4m band dipole finally fitted

My local area has quite an active 4m band, and recently Andy (G6OHM) has gained an NoV for a 4m simplex parrot which is working well.

Kevin (2E0OPU)kindly gave me a 4m band dipole as he knew I had an Icom 7100 and no antenna, so I finally got round to installing it.

I did a temporary setup at ground level and got the VSWR to 1.0:1, mounting the antenna in it’s fixed location would not allow me to get the VSWR below 1.6:1 (this would give me a reflected power of 5.3%).

The cause of this problem was the close proximity of my mast, extending the dipole 300mm past this structure solved the problem.

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The dipole is horizontal for an SSB contest at the moment, I have used a stand off sleeve which the dipoles supporting tube slides into, this allows me to retract the dipole for fine tuning, a self tapping screw is used to hold the dipole either horizontally or vertically.

The bracket for the dipole was their before the mast, hence in the horizontal plane, the dipole it is across the mast stopping it from tilting for maintenance, as I have to get up the ladder to pull the mast top securing pin, it’s no big deal as I will move the dipole out of the way at the same time.

The VSWR is 1.0:1 or as near as damn it!

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Radio Mast Automation – Part 1 – PLC or Relay Control

Note – This is the starting point in my mast automation project, several things ‘evolved’ during the overall project, therfore as you read through this and get to the end of the Parts, you can see the changes, tweaks and additions which have improved the project.

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My mast has an winch to raise and lower the inner section of the mast.

This project is to fully automate the process and add a level of intelligence into the mix, my requirements list is:-

  • Automatically stop the motor at the top or bottom
  • Run-On when mast lowered to release tension from cable
  • If bottom mast inner securing pin is in – Stop mast from raising or lowering
  • Disallow inputs whilst the motor is either lifting or lowering
  • Safety timer on the motor operation should a limit switch fail
  • Means to stop holding an input button increasing the motor run time
  • Don’t lower the mast if the luffing pin is removed
  • Override to allow either a pulsed automatic operation or manual hold for up & down ignoring limit switches
  • Emergency stop
  • All timing sequences reset on restoring emergency stop or override to prevent motor operation
  • Interface with WX Station to automatically lower
  • Visual display of status – what is doing what
  • Automatic battery charging after a number of counted operations or weekly – whichever comes first
  • Battery charging does not interfere with solar panel charging

I was going to use relays, and made a start on the construction, but the more I thought about interlocking and timers the more unrealistic this option became.

SAM_5618 (Small)

The relay unit currently in use which works fine is shown below, two of the relays are for the raise and lower switches, the other two are for overrides.

SAM_5472 (Small)

My plan is to use a Programmable Logic Controller (PLC) which needed to have 12 inputs and 4 relay outputs.

I found a company on the internet called Audon.co.uk, the model chosen was ELC-18DCD-R-U at £69 ex VAT and I also bought a RS232 programming lead for just under £20 ex VAT, the PLC has a voltage range from 12 to 24v DC is very compact and will do everything I need and more.

A major plus was the programming software is free and very easy to use.

elc_18_c

Link to PLC Software Link

Link to PLC Manual

The drawing shows the sensor positions, currently the mast only has up and down limit switches fitted, the upper and lower securing pin detection will be fitted when the parts arrive from the other side of the world.

Mast Contro2l

The way of working will be:

Normal Up & Down

Momentary pressing of the down button on the remote hand held winch unit, will fully lower the mast, pressing the up button will do the reverse.

Luffing the Mast

Luffing (Tilting down) of the mast for maintenance will involve setting the PLC input switch to Luff, this will only lower the mast if the mast is lowered, the lower securing pin is in and the upper securing pin is out.

The logic plan shown below has been imported from the software program into Visio and I’ve added some idents to make it easier for me to fault find at a later date.

Descriptors for the idents is below.

The next stage of the project is to mount the PLC in an enclosure and fit the securing pin sensors, please see Part 2 HERE.

Dummy Load Refurbishment

At a recent surplus sale at my local radio club (Cambridge & District Amateur Radio Club) I bought a dummy load for £5, getting it on the bench the resistance at the PL259 socket measured 88 ohms.

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I also knew that the internal cooling fan was  U/S, so I stripped everything out of the case, ready for cleaning and reassembly.

The tubular resistors have an copper shim inside the aluminium clamping brackets, all parts were cleaned and degreased and put back together, on the rear heat sink I used heat transfer paste, and after replacing the internal fan, installed a cheap thermostatically controlled switch which I got from ebay, the temperature sensor is bonded to the rear resistor clamp .

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The temperature selection is set by dip switches on the PCB, I set the fan to operate when the temperature is greater than 35c, power to the PCB is via a fused 2.5mm DC socket.

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After reassembly the resistance dropped the 46 ohms and the fan kicks in when tested.

My homemade paint tin dummy load works great but the mineral oil is ‘wicking’ up the cables and finding its way to freedom, this one will mean the paint tin being relegated to the shed.

iPhone 6 WiFi Connectivity Issues and HG633 Router Solved

I have recently upgraded my Broadband package and this came with a HG633 router, blog on this is here: Router Upgrade, a day or so after installation Apple updated my daughters iPhone 6 after this update the phone kept dropping in and out of WiFi connectivity.

A the router was new and my Samsung Galaxy worked fine as did the i tablet mini, so it pointed to her phone.

Cutting a long story short including swapping the phone for a new one, the problem seems to stem from the fact that the HG633 has two WiFi frequencies available (5GHz and 2.4GHz), both being ON by default and sharing the same SSID, this makes the iPhone 6 very unhappy.

The problem of frequent disconnects and reconnects was solved by entering the router setup and renaming the WiFi SSID’s so that each frequency had a unique identification, based on the signal strength is the frequency you ‘pair’ with, this has cured the problem.

Hope this helps bring peace and harmony back into the homestead.

download (Small)
Apple update (Feb 16) causes frequent WiFi connection issues with HG633.

 

Router & RAM Upgrade

I have had Fibre to the Home for a while at 38Mb download speeds, Talktalk my ISP offered 76Mb download speeds for a small increase in costs, the engineer called today (27 Jan 16) to check my actual speeds which were well below that quoted and installed a new HG633 router.

The problem of reduced speed performance is Openreach’s as its infrastructure, so I’ll have to wait and see, the current download speed is 56Mb so still not too shabby for here.

Manuals  for the Huawei HG 533 can be found here, the actual HG633 manual I haven’t managed to track down yet.

hg633

At the same time of the Broadband upgrade, I decided to increase the RAM in my Weather PC from 8Gb to 32Gb as it was regularly running at 7Gb used, the PC is a Dell Precision T490 and uses Server RAM modules which cost a total of £60 from ebay.

Davis Vantage Pro2 Fan Change

I check and clean my weather station twice a year, just before Christmas I noticed the  FARS (Fan Aspirated Radiation Shieldfan which draws air past the external temperature and humidity sensor had stopped working, (write up from a previous blog on how I installed it is here –FARS Link).

As an interim measure I increased the voltage to the fan from 1.7v to 2.8v, which kept the motor working for a few more weeks before it finally wouldn’t kick into life.

In February 2014 I had bought 5 spare motors (minimum order but cheap as chips) from Jameco.com, so today I decided the weather wasn’t going to catch me out  and I made a start on replacing the fan.

Disassembly of the unit is very easy, removing the Rain Bucket exposes three cross head screws which hold the FARS in place, whilst holding the base of the FARS, undo each of the screws until you have the weight of the FARS in your hand, slowly lowering your hand the weight of the unit will be held by the interconnecting wires to the ISS.

The power to the fan is via a small plug and once removed, the fan assembly slides out of the shield as one unit.

The fan is held onto the motor by an interference fit, pulling on the fan will remove it from the motors shaft.

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The motor is held in the fan body by silicon, I used a craft drill with a tapered bit to remove this.

2016-01-23 09.41.35It didn’t take too long to get the motor out, the next job was to tidy the fan body socket and de-solder the old fan motor wires.

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New motor from Jameco compared to the one removed just in case I had ordered the wrong one!

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The motor needs packing to center it in the fan body, jerryg on the WXForum gave his solution of using insulating tape to build the diameter and this works really well, I made it so the motor was a snug, but not tight fit (as the motor uses brushes to make electrical contact to the rotating commutator, the motor will inevitably fail and need replacement).

The motor has three holes at the shaft end of the body which in the the original motor had been taped over, so I did the same, pushing the motor in the body I used a few dabs of silicon to hold it in place and pushed on the, the last part of this job was to solder wires on making sure the red wire went to the terminal marked with a + sign!

Once connections are made, a cable tie holds the wires neatly to fan body.

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While everything was apart, I checked the voltage regulator to the fan to make sure everything was ok, this is a Velleman unit with 24vAC in and I have removed the potentiometer and replaced it with a fixed value resistor giving a stable output of 2.8v DC.

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After a washing  down with soapy water the tipping bucket, Stevenson screen and rain bucket, everything was put back together, the total time taken was about an hour, now I know what I need to do, this could be done in under 30 minutes.

If you prefer to simply change the complete fan unit (Davis 7758), this can be bought from Weatherspares  in the UK who offer exceptional customer service.

Just got to see how long this motor lasts, once all the motors I’ve bought are gone, I’ll put a PC fan motor in and monitor the output to generate an alarm, I have made a a circuit based on this site, but I need to play a bit more to get it to work properly.

 

Chatteris Weather Page Updates

Over the festive break, I’ve taken the opportunity to tweak my weather web pages and add a few features:-

  1.   Meteotemplate

This is a new style dashboard accessible from the menu bar of Chatteris Weather, if you prefer this template, save it as a favorite.

Jachym, the author of the script is continually adding new functionality and wherever possible I will adjust my site to incorporate his hard work.

2.   International Space Station (ISS)

I have always had a link to the ISS, but now Maj Tim is orbiting, I thought it would be fitting to have a bespoke page showing the live camera stream and graphical overlay of where the ISS is in real time.

3.   Live Webcam

I have recently fitted a Hikvision IP webcam which is streaming live video 24/7. I’m working on the time lapse feature and this will follow shortly.

4.  Supercounter

I have had revolver map on my site for a while as well as a whos-online script and PHP Web Stat, Supercounter was very easy to set up and implement, site statistics are available from the above link, what is of interest is that the majority of refers have come from webcam sites.

5.  Page Header Image

New design which will change to reflect either a reason to celebrate, when not a special header, a new standard image will be used with a change of title from Chatteris Weather to Chatteris Weather Station.

6.  Status Page

Added a screen grab image of the Weather Display program which drives Chatteris Weather, looking at the image you can see at a glance the overall conditions which are updated every 5 minutes.

Construction of More Blitzortung Lightning Detectors

I offer my help to the Blitzortung Forum members who find soldering is not for them, especially the tiny components; the  boards below are:

Top Left –  Blitzortung Controller with pre made daughter board plugged in

Top-Right – Amplifier which interfaces the antennas (not shown) to the controller

Bottom Left – E-Field Amplifier connects to controller

Bottom Right – E-Field Pre Amplifier  connects to E-Field Amplifier

SAM_5587 (Medium)The owner of the boards (Julian – Bremen, Germany) had kindly put all the parts in uniquely identifiable bags which certainly saved me time usually spent in sorting out the components.

In total I spent about 9 hours building up the boards and installing the firmware in the daughter board, hopefully that will be another one on the Blitzortung network.

General information and status updates.