Eggciting HAB projects

I have a new high altitude balloon project, this one is very Eggciting.

In June my club South Kesteven Amateur Radio Society (SKARS) will be operating a special event station at the Swaton Vintage Day held at Thorpe Latimer in Lincolnshire. 

The 2015 Swaton Vintage Day will also host the 10th World Egg Throwing Championship  and in recognition the special event station will have the call sign GB2EGG. This popular annual show raises money for local, national and international good causes.

Egg Throwing is recognised by the English Sports Council and the sport is taken very seriously by some competitors. Hundreds of competitors from Europe and around the world are expected to compete this year. Last year’s event attracted teams from Germany, Slovenia, Hong Kong and Brazil.

While planning the special event station I jokingly suggested throwing an egg in to space on board a balloon, I shouldn’t have yoked as it is now a serious project. The idea coming from Dave Akerman’s Spudnik flight for Heston Blumenthal’s Channel4 television program.

Image with the permission of Dave Akerman

Subject to Civil Aviation Authority clearance and weather conditions I will hopefully launch a high altitude balloon carrying one lucky egg into the edge of space and then dropping it back to earth under a parachute. In addition to the plucky Eggstronaut the balloon I have called Eggsplorer-1 will carry a radio transmitter to broadcast its position, altitude and live images of the journey back to earth.

On board cameras will record the journey to be recovered on a successful return to Earth. Radio enthusiasts all around the country will be able to assist receiving the data and pictures and track the progress of the flight via the UK High Altitude Society tracking website.

More details and progress will be posted on here and on the Eggsplorer-1 website  and you can follow developments on twitter @eggsplorer1South Kesteven ARS welcomes anybody with an interest in radio communications, so if want to be involved in this and other events like this please visit us at the show or visit the South Kestevan ARS website and on twitter @M0SKR

I have already begun development of the payload, unlike the moth-balled NERD-1 payload this one will use one of the Raspberry Pi boards since I want to transmit SSDV images live and it supports its own specially designed camera modules. NERD-1 will still fly as a backup tracker.

Dave Akerman (M0RPI) and Anthony Stirk (M0UPU) have developed the Pi-In-The-Sky ready made boards and the design and software are open-sourced, using this as a starting point together with Phil Heron’s (MI0VIM) SSDV software I quickly had a prototype dubbed NERDPI running.

I did have an issue since the GPS module I currently have only outputs serial data so had to use one of those small TTL USB-Serial adapters and spun some of my own code to get the data out and was soon successfully decoding my own transmissions from the shack and uploading them to the Habhub system.

Today has seen the spectacular partial solar eclipse here in the UK, during the eclipse several HAB flights were launched to try to capture images above any cloud cover (details here)  Fellow SKARS members and members from the Grantham ARC were keen to decode the SSDV images themselves as the BBC Stargazing Live balloons were flying from nearby Leicester.

So on Wednesday I did a talk and demonstration to show how to track and decode the images, it was well received and I uploaded pictures of the audience to the system.

Unfortunately technical issues prevented live images from the Stargazing HABs being transmitted but I was able to decode some images from the University of Southampton OLAF payload They were only lo-res but still pleased to get decodes here it was a good distance from me.

Here in Newark the sky was beautifully clear so the eclipse was visible and spectacular, where OLAF was flying was covered in cloud, so the mission was a success.

   

Grantham ARC HAB Talk

Yesterday I gave my talk and demonstration at the Grantham Amateur Radio Club on High Altitude Ballooning and tracking.

This follows on from the South Kesteven ARS (SKARS) and the Spalding and District ARS (SDARS) talks I gave in May

It was very well attended with a large number of GARC members turning out. It was a case of everyone going in at the same time once the venues key holder turned up and I initially got a little stressed as I hurriedly tried to get everything set up while everyone sat patiently waiting.

Picture by Kevin Burton

The first issue I had was the projector seemed to be limited to just 800×600 pixels, which was fine for the PowerPoint presentation but for demonstrating reception using a RTL-SDR with SDRSharp and decoding using DL-FLDIGI and the UKHAS Habitat tracking system spacenear.us/tracker the lack of screen space was a problem, DL-FLDIGI couldn’t be shrunk down to fit, so there was a lot of scrolling about!  

The second issue was the venues wi-fi connection, my laptop stubbornly refused to connect to it (I wished I’d taken a ThinkPad laptop I have instead of the one I did as it has a better wi-fi adapter) so was forced to use my mobile phone as a tethered hotspot – while it worked the connection was painfully slow.

Despite these issues I was able to give the presentation about the HAB community and the technology. It contains a lot of information to digest but there is some light relief with its videos of Felix Baumgartner, Dave Akerman’s Babbage Teddy Bear free fall and wacky chef Heston Blumenthal’s ‘Spud-in-space’ feature from his recent television program.

I demonstrated Project Hab‘s VAYU-NTX tracker and thanks again to Steve Smith  (G0TDJ) for its loan.

I ran my own prototype tracker (NERDTEST) which I had updated to simulate a local flight, the transmission, reception, decoding and uploading to the UKHAS Habitat system was completely genuine, both using SDR and a traditional radio (Alinco DX-10) hooked up to the sound card. The only thing fictitious were the GPS coordinates and altitude.  (A programming error in the first version of this simulator had the balloon travelling at near 10km/s, thankfully I had corrected it to something more realistic)  

The poor internet connection cause issues with spacenear.us/tracker but was able to use Phil Crump’s (M0DNY) version at at habmap.philcrump.co.uk to demonstrate the real time map tracking.

Checking the spacenear.us map this morning and the receiver station at the club house and the demo flight could still be seen – it was programmed to take off from a nearby high point!

By lucky coincidence Chris Stubbs (M6EDF) had launched a balloon CARS-1 from the Chelmsford Amateur Radio Society meeting at Oaklands Museum where he was giving a talk and demonstration at the same time as my talk, so I was able to show how multiple receiver stations were tracking a real flight.

I was also able to demonstrate SSDV image decoding using some recorded SDR files of the HiPi flight

I thought I had overloaded the attendees with too much information, lots of references to Arduino, Raspberry PIs, SDR, dongles, GPS could be quite daunting to the uninitiated but again feedback has been very positive. Grantham Amateur Radio Club on Facebook

Now I just to sort out doing a proper flight!

HAB Talks

I was shocked when I realised it has been nearly two months since my last update. The pace of life really hasn’t let up and neither have the time pressures of work, however on with recent radio antics…

Last week I gave two talks and demonstrations at local radio societies on High Altitude Ballooning in the UK and how to track them.

The first was at South Kesteven ARS (SKARS) the club I am a member of. The second was at Spalding and District ARS (SDARS)

This was an updated version of the talk I gave last year at SKARS. Since then I have started work on my own tracker NERD-1. Sadly development has stalled and is still only at the prototype stage (NERDTEST) but I was able to use it to demonstrate reception and tracking using the UKHAS Habitat system spacenear.us/tracker

The SDARS venue had a projector and a decent WiFi Internet connection which allowed me to demonstrate how to set up DL-FLDIGI for a ground station and NERDTEST being received and both showing up on the map in real time.

My original PowerPoint presentation has been given a total makeover and I has included some videos of Felix Baumgartner, Dave Akerman’s Babbage Teddy Bear and wacky chef Heston Blumenthal’s ‘Spud-in-space’ feature from his new television program.

To show a real tracker Steve Smith (G0TDJ) of Project Hab had been kind enough to loan me his VAYU-NTX unit.

I am not the most confident of people when it comes to public interaction and it was encouraging to see people genuinely interested in what I was talking about and keen to have a look and I have had some very nice feedback.

Thanks @nerdsville for an excellent talk on High Altitude Balloons and telemetry, look forward to your launch. pic.twitter.com/H8AevMNQ13
— Spalding DARS (@SDARS) May 16, 2014

Excellent talk at Club tonight by @nerdsville on high altitude balloons and radio data. Andrew knows his subject and enthusiasm infectious.
— Jim Scott G0HGH (@photoimagery) May 16, 2014

Giving these talks has spurred me to pull my finger out and get on with actually flying something and finishing the payload!

Another mothballed project is my Ultimate3 beacon kit, still being only a Foundation licence means I cannot use it to transmit but that may be about to change as tomorrow I am sitting my Intermediate exam which will allow me to properly experiment with transmitters. The exam was arranged through SKARS by Chairman Nigel Booth and the date came through a little sooner than I was expecting so perhaps not quite as prepared as I really should be, but with a decent electronics background and some quick revision it should be fine….

My operating has been largely limited to the UKAC VHF contests, setting aside a few hours per week is manageable and my results are gradually improving, even getting some complements on my operating.
  
Two weeks ago I was able to attend the local Dambusters Hamfest at Thorpe Camp and managed to pick up a decent rotator, this has proved invaluable for the UKAC as I don’t have to keep going outside the shack to turn the antenna.

Now if I hear someone calling CQ and can monitor a QSO to get the locator and the bearing a quick turn of the dial and I have a better chance. The program I use is BD_2004 from W1GHZ, running in console window it is a simple case of setting up your own locator and then entering other locators the bearing and distance are given.

As well as the weeknight UKAC there have been a couple of weekend VHF contests, I managed a couple of hours this weekend on the RSGB 144MHz May Contest and I had the best DX ever and nearly every QSO was in a new locator square!

I wasn’t able to spend more time on the contest as we took the dogs on a sponsored dog walk on Sunday in aid of the local hospice and on Saturday I attended the British Astronomical Association, Radio Astronomy Group General Meeting at the National Space Centre.

The notion of amateur Radio Astronomy is something that has fascinated me, up to now the only dabbling I have done has been with meteor detection using reflections from the Graves space radar (blog entry). This year some of the talks dealt with using RTL-SDR and Arduino/Raspberry PI in low-cost observation. Also at the meeting was a number of demonstrations and stands from other projects we I was able to garner a great deal of useful information.

Being able to detect ‘Hydrogen-Line’ emissions to map the Galactic plane using a FUNCube or RTL-SDR dongle is astonishing, not to mention low cost VLF receivers to detect Sudden Ionospheric Disturbances SIDs and magnetometers to measure the effect of the solar wind on the earth’s magnetic field!

It is all on the to do list, but it was a great day with some really fascinating talks and some exciting plans by the group. It was a shame I had to leave earlier than I wanted as I did miss some of the later presentations.

Anyway best get an early night! 

Arduino, WSPR and AD9850 DDS experiments

Happy New Year!

Christmas is thankfully behind us so I can get back to what I enjoy doing once I have reorganised my workshop.

As you know I am currently developing a potential High Altitude Balloon (HAB) project and have been experimenting with the Arduino microprocessor platform and have constructed a basic prototype.

With the arrival of the GPS module(s) I have had it successfully working and even took it out for a test walk in the local area, receiving the data and uploading it to the UKHAS habitat system.

NERD-1 and Boris have just been for a walk, first time NERD-1 has had proper GPS and running on batteries. #hab pic.twitter.com/RaKsf1rQhr
— Andrew Garratt M6GTG (@nerdsville) November 23, 2013

This project has revitalised my interest in ‘hobby electronics’ and I have ideas for a number of other Arduino based projects and have been splashing out on components from eBay. Just before Christmas I purchased an Arduino Mega board, this has more I/O pins than the current Uno and specifically some extra hardware serial ports.

Do any internet search for Arduino based amateur radio projects and it will results in numerous mentions of projects using ultra cheap DDS modules based on the Analog Devices AD9850/AD9851 chipsets.

DDS means Direct digital synthesiser and is a type of frequency generation which can be used for creating arbitrary waveforms from a single, fixed-frequency reference clock. Read the Wikipedia page for more details.

In a nutshell the AD9850 is a chip that under microprocessor control can produce a sinusoidal wave from about 1hz to 40mhz. In other words it is an accurate microprocessor controlled VFO (Variable Frequency Oscillator) or signal generator.

VFOs are the main building blocks of radio receivers and transmitters, so not surprisingly a lot of projects have utilised these modules, rather than the traditional means. Intrigued I ordered a couple of these modules for the pricey sum of £3.50 each!

Using information on George Smart’s (M1GEO) website and Simon Kennedy’s (G0FCU) blog  I quickly had a simple WSPR beacon running!

Experimenting with Arduino and AD9850 DDS and GPS unit.. pic.twitter.com/rxDHQQ1aFd
— Andrew Garratt M6GTG (@nerdsville) December 29, 2013

The Arduino uses the GPS module borrowed from NERD-1 for accurate time and then controls the output of the AD9850 DDS to generate the WSPR signal.

Before anyone panics I know at the moment I only hold a Foundation Amateur Licence so the construction of homebrew transmitters isn’t allowed. This ‘beacon’ has no power amplifier and the antenna consisted of an inch or so of wire on the DDS output. I was able to verify the operation using my SDR receiver in the same room.

Construction of commercial kits is allowed under my licence so I have ordered a Ultimate3 QRSS kit from Hans Summers for the pricely sum of £17.50! This uses the same DDS module and same microcontroller as the Arduino.

In the meantime there is also more information and ideas on Eugenr Marcus’ (W3PM) webpage about the use of these DDS modules, including making frequency reference sources and calibration using the GPS module.

My new year resolution is to get my Intermediate Licence as soon as possible..  but it has been great to get down to some proper experimenting…

Cannot beat a picture of an oscilloscope to look techy.. my DDS experiments continue… pic.twitter.com/T9OLHOdTLW
— Andrew Garratt M6GTG (@nerdsville) January 1, 2014

NERD-1 development prototype

The NERD-1 HAB development prototype has been coming on in leaps and bounds. The first stage was to take the breadboard transmitter layout and construct a veroboard ‘shield’  the transmitter module plugs into some sockets and the addition of an enable control allows me to turn it off and on. What cannot be seen on the photo below is a dual-colour LED to indicate the fix status of the GPS.

Veroboard shield with transmitter fitted

I am still waiting for delivery of the uBlox GPS module/breakout board which is on a slow boat from China, but in the meantime I have purchased a number of other breakout boards (pictured below) to evaluate potential additions and to generally experiment.

Top-Bottom, SD Card module, RTC/EEPROM module and GY-80 IMU

These include a SD Card module, which will be used to log flight telemetry via the SPI interface. The board on the right is a Real Time Clock (RTC) including a button cell and some EEPROM memory accessed and controlled via the I2C/Wire interface. This really isn’t needed but was literally a couple of £s.

The smaller board at the bottom is the really interesting one! It is a GY-80 IMU clone, containing a three-axis gyroscope, three-axis accelerometer, three-axis magnetic sensor and a temperature and pressure sensor, again all accessed simply via the I2C interface. Popular in aeronautical RC and personal UAV projects such as Quadcopters it seemed worthy of some experimentation.

All the devices were purchased from Etang Electronics on eBay and was impressed as it all arrived the day after ordering.

I am using the only proper serial port for the GPS data and  I wanted some method of getting debugging and instrumentation from the device during testing. I could have constructed a software serial port but I had an unused LCD character display so decided to connect it up (won’t be included on a proper payload!)

It looks nice and is ‘cool’ however the backlight LEDs do draw an awful lot of current so have been disconnected since the picture was taken.

LCD Character display

At the moment the whole thing is a little messy, but is functional and sits in it’s own foam lined box!

The prototype connected up (still no GPS module)

The software development has been pretty straightforward, I am no stranger to the use of I2C and SPI in my day job and there are plenty of software libraries and guides available. Once I have perfected the software and settled on the final design then I am planning on constructing a veroboard flight prototype with all the unnecessary parts removed.

I have also yet to investigate another transmitter unit I have purchased.  

NERD-1 HAB Development begins!

The prospect of developing a High Altitude Balloon payload doesn’t fill me with dread, after all “embedded software engineer” is my day job. It is a varied job including PC, Linux and other programming but it is mostly microcontrollers and associated electronics.

What did fill me with dread was the prospect of going out and getting some development kit! I like to switch off from work when I get home so I have never duplicated a development set up at home to resist the temptation to carry on working. So how was I going to go about this on a small budget?

The obvious solution was to use one of the educational and hobbyist systems like the RaspberryPI, Arduino, Propeller or BeagleBoards which have become increasingly popular. I hadn’t kept abreast of any of them but after examining the work of HAB enthusiasts and some very rudimentary research I decided to try one out and the cheapest was the Arduino route.

So a quick trip off to eBay and I got hold of an ‘Funduino’ (an Arduino UNO clone) board for £9 and ordered a uBlox GPS module/breakout board from China (which is still to arrive) as well as a couple of radio modules including the Radiometrix NTX-2 used in many HAB flights.

We call me impressed, after installing the Arduino development system I had the board flashing an LED within 30 seconds! When I was learning electronics and computing back in the early 1980s at school I would have killed for a platform like this!

I took the liberty of downloading Steve Smith’s (G0TDJ) ProjectHAB VAYU ino file as a starting point. This ino or ‘sketch’ file is Arduino terminology for a project. They may be called ‘sketches’ but rarely has any of my software ever been called a work of art!

This iteration of VAYU uses the RFM22B radio module controlled by SPI, whereas the NTX-2 is much simpler to control using a digital output and a few resistors. There are many handy guides on the UKHAS Wiki

The GPS data will be coming in serially on the UART the same as VAYU so it was trivial to make the modifications and remove the SPI control to get a barebones flight computer running. I was able to breadboard the NTX-2 and had it successfully transmitting from my lounge floor. It even passed its first environmental test of having one of my dogs lick the circuit board while powered up!

UNO and breadboarded NTX-2
The RTTY transmission being received in another room.

However the current payload might be a bit heavy even for a large latex.
 

The Payload!

The blue mouse shaped device on the left hand of the laptop is an old Haicom HI-204 GPS module which I have had kicking around for years. It is actually a serial device which once powered up starts outputting NMEA data at 4800 baud, this model has an intergrated serial-usb adapter.

When not running the Arduino IDE the UNO board appears as a standard serial port on the PC and can accept or output data, so all I needed to do was route the serial data from one port to another.

I of course made more work for myself by deciding to taking the open source SharpGPS C# based windows program and customising it. As well as decoding it can now forward the data and NMEA sentences from a GPS device on one port to another serial port. It can now log the raw data and play back logs to emulate a device for testing.

The nice thing is this program informs me of the location data, fix status and information about satellites and if and when I iron out some of the remaining bugs and quirks it will make a nice utility which I will make available. Here are some screenshots of it in action.

Now to the next stage….