Posts Tagged ‘hab’

868MHz LoRa HAB Tracking Success

Most HAB (High Altitude Balloon) tracking in the UK involves the use of 434MHz ISM devices due to the ready availability of suitable antenna and receiver equipment due to it sharing the 70cm amateur radio bands.

868MHz ISM devices are available but are not as widely used. Back in December I posted about trying to track a flight by HAB Enthusiast Dave Akerman who is experimenting using LoRa devices on this band. I had limited success receiving that flight and another ones so when I saw that Dave was planning another flight today using 868MHz LoRa I had a rethink on how to approach tracking it.

The antenna I used was a collinear one built from cheap satellite coax, similar to that I built for ADB-S however rather than having a long coax run to the LoRa gateway I opted to put the Raspberry Pi up on the pole at the base of the antenna to limit any loss.

The antenna can be seen connected to the Raspberry Pi and LoRa add on board, the Pi has a WiFi dongle.


The antenna was inserted into a piece of conduit to keep it upright and it and the Pi were strapped to a 5m painters pole (using a plastic lid as an insulator)


A USB power pack was also strapped to the pole to keep the Pi powered, hopefully you can see it in the photo below.


The pole was put up and was about the same height as my normal dual band collinear


Well it all worked extremely well, and got a lot of decodes as can be seen by the pie-chart generated by the habitat.habhub.org system, the third best receiver only bettered by Dave himself (M0RPI) and a station nearer to the flight path.

You can see my geographical position relative to the flight below (I am the station NNE with the green line, about 160km away) and received a lot of telemetry strings even when the height of the balloon meant I was outside the 5 degree above the horizon circle (shown in green).


The Pi was connected to my network via WiFi and controlled by a Putty console on my shack PC


It was a useful experiment and I am thinking of installing a dedicated mast mounted LoRa receiver with 868 and 434MHz antennas (and possibly pre-amps and filters) following this result.

LoRa LoRa Laughs!

Due to the restrictions on airborne amateur radio operation in the UK High Altitude Balloon (HAB) enthusiasts have been forced to utilise licence exempt low power devices in novel ways to make radio trackers for their payloads. I have written plenty on this blog about my HAB tracking, the UKHAS distributed listener network and my own flights.

Until recently the preferred method was to use RTTY transmissions, however the advent of the IoT (Internet Of Things) has seen manufacturers of radio modules develop devices to increase both the range and reliability of communication between 'connected' embedded devices.

One such development are LoRa devices, primarily for devices to connect to a global wide-area network LoRaWAN, more information can be found at the LoRa Alliance in addition there are some open hobbyist networks such as The Things Network using these devices.

Using chirp spread-spectrum modulation these LoRa devices are marketed as being capable of robust, interference and fade resistant communication over longer distances and higher data rates.

The UK HAB community has begun experimenting with these devices and one of their keen proponents is Dave Akerman (M0RPI). Dave has developed both payload software for the "Pi In The Sky" PITS tracker along with Anthony Stirk (M0UPU) and gateway software in collaboration with Robert Harrison M0RJX. The 'gateway' is the necessary receiver element to upload the data to the tracking system. (all software is on the PITS Github page)

Dave gave an informative presentation on LoRa at the UKHAS 2016 Conference which is now available online (starts around 3 minutes in)


I had intended to fly a LoRa transmitter on my 2015 Hamfest balloon but it stopped working at the eleventh hour and hadn't done anything else with LoRa till recently.

Spurred on by the conference presentation and the fact more and more flights are carrying LoRa I invested in one of the Raspberry Pi expansion boards sold by Uputronics and built up another prototype tracker with a working LoRa module.

I have done talks at various radio clubs and societies and demonstrated it working but hadn't actually received a 'real flight' as opportunities have been scarce due to the weather. However in the few weeks I have tracked a couple of flights receiving both telemetry and image data, getting a couple of complete images from the imaginatively named 'SPACE' flight.


Dave Akerman also flew a flight experimenting with multiple payloads using Time-division multiplexing (TDM). It had 10 small of "AVRLoRaNut" trackers (of Anthony M0UPU's design) all set to the same frequency (434.450MHz) and same transmission mode. The trackers took turns to transmit, with each one allocated a particular transmission slot in a 20-second cycle. The cycle was GPS-timed but, if any tracker lost GPS lock then it derived timing from the transmissions from the other trackers (the LoRa devices are also receivers) All 10 trackers were suspended from the same balloon. This was in preparation for the 'Operation Outward' re-enactment next year (Steve Randall gave a presentation on it in the above conference video starts 1 hour 16 mins in)

I successfully received telemetry despite the flight not being local and constantly heading away from me as can be seen in the screen shots.


Always a busy man Dave also flew a flight with an experimental camera setup. The SSDV images this time came from a Nikon compact camera, connected to the Raspberry Pi via USB, and using gphoto2 software to take and transfer images to the Pi where they were stored, resized and converted to SSDV format for transmission. These were large images with a high quality SSDV setting so lots of packets per image, approx 1400 per image in testing. 

This flight was using a 868MHz LoRa device, rather than the usual 434MHz due to the IR2030 restriction on bandwidth and duty cycle. Dave was using his Turbo-X or Mode 4 setting which is as fast as LoRa will go within IR2030 bandwidth restrictions (approx 8 packets / 2k bytes per second)

I hastily ordered a 868MHz device and soldered it in the spare slot on my gateway and built a collinear for 868MHz similar to the one I built for ADB-S reception (see video here).


You can see it lashed up just below the dual-band collinear - not ideal mounting and it wasn't tested in anyway, built blind!  The less than optimal setup at UHF, the insane data rate and the distance (>100miles) were going to make reception difficult, so I was pleased I did manage to receive telemetry and image packets.

 
Most of the current LoRa development in the HAB community has tended to be on the Raspberry Pi due to the use with SSDV and the easy availability of cameras and ready built kit. LoRa is of course available on the Arduino platform and I had purchased a couple of 'Dragino' shields (pictured below) with a LoRa device on.


Dave has done some work on a AVR tracker software and a simple Arduino 'Serial' LoRa receiver. The receiver connects to a host PC appearing as a serial port and by running some gateway software the receiver can be configured via the serial link and received data is sent back to the gateway to be uploaded to the Habitat tracking system and SSDV system - the software can be seen here during the 'Operation Outward' test flight.


This gateway software is written in Pascal using Delphi and is not as functional as the Raspberry Pi Gateway software. Dave has made the source code available but I am not au fait at all with Delphi however I installed the free development IDE and intended to get in and make modifications but it seems to require a non-free(?) library for the serial comms so ditched the idea.

Instead I have spent the last few days developing a C# .NET version using Microsoft Visual Studio (the community version is free) and also have been modifying the Arduino code in the receiver to add functionality, such as storing the SSDV images locally.

It is still a work in progress but I have made a video showing the current state


Anyway as Cilla Black would say it's been a Lorra Lorra Laughs!


LoRa LoRa Laughs!

Due to the restrictions on airborne amateur radio operation in the UK High Altitude Balloon (HAB) enthusiasts have been forced to utilise licence exempt low power devices in novel ways to make radio trackers for their payloads. I have written plenty on this blog about my HAB tracking, the UKHAS distributed listener network and my own flights.

Until recently the preferred method was to use RTTY transmissions, however the advent of the IoT (Internet Of Things) has seen manufacturers of radio modules develop devices to increase both the range and reliability of communication between 'connected' embedded devices.

One such development are LoRa devices, primarily for devices to connect to a global wide-area network LoRaWAN, more information can be found at the LoRa Alliance in addition there are some open hobbyist networks such as The Things Network using these devices.

Using chirp spread-spectrum modulation these LoRa devices are marketed as being capable of robust, interference and fade resistant communication over longer distances and higher data rates.

The UK HAB community has begun experimenting with these devices and one of their keen proponents is Dave Akerman (M0RPI). Dave has developed both payload software for the "Pi In The Sky" PITS tracker along with Anthony Stirk (M0UPU) and gateway software in collaboration with Robert Harrison M0RJX. The 'gateway' is the necessary receiver element to upload the data to the tracking system. (all software is on the PITS Github page)

Dave gave an informative presentation on LoRa at the UKHAS 2016 Conference which is now available online (starts around 3 minutes in)


I had intended to fly a LoRa transmitter on my 2015 Hamfest balloon but it stopped working at the eleventh hour and hadn't done anything else with LoRa till recently.

Spurred on by the conference presentation and the fact more and more flights are carrying LoRa I invested in one of the Raspberry Pi expansion boards sold by Uputronics and built up another prototype tracker with a working LoRa module.

I have done talks at various radio clubs and societies and demonstrated it working but hadn't actually received a 'real flight' as opportunities have been scarce due to the weather. However in the few weeks I have tracked a couple of flights receiving both telemetry and image data, getting a couple of complete images from the imaginatively named 'SPACE' flight.


Dave Akerman also flew a flight experimenting with multiple payloads using Time-division multiplexing (TDM). It had 10 small of "AVRLoRaNut" trackers (of Anthony M0UPU's design) all set to the same frequency (434.450MHz) and same transmission mode. The trackers took turns to transmit, with each one allocated a particular transmission slot in a 20-second cycle. The cycle was GPS-timed but, if any tracker lost GPS lock then it derived timing from the transmissions from the other trackers (the LoRa devices are also receivers) All 10 trackers were suspended from the same balloon. This was in preparation for the 'Operation Outward' re-enactment next year (Steve Randall gave a presentation on it in the above conference video starts 1 hour 16 mins in)

I successfully received telemetry despite the flight not being local and constantly heading away from me as can be seen in the screen shots.


Always a busy man Dave also flew a flight with an experimental camera setup. The SSDV images this time came from a Nikon compact camera, connected to the Raspberry Pi via USB, and using gphoto2 software to take and transfer images to the Pi where they were stored, resized and converted to SSDV format for transmission. These were large images with a high quality SSDV setting so lots of packets per image, approx 1400 per image in testing. 

This flight was using a 868MHz LoRa device, rather than the usual 434MHz due to the IR2030 restriction on bandwidth and duty cycle. Dave was using his Turbo-X or Mode 4 setting which is as fast as LoRa will go within IR2030 bandwidth restrictions (approx 8 packets / 2k bytes per second)

I hastily ordered a 868MHz device and soldered it in the spare slot on my gateway and built a collinear for 868MHz similar to the one I built for ADB-S reception (see video here).


You can see it lashed up just below the dual-band collinear - not ideal mounting and it wasn't tested in anyway, built blind!  The less than optimal setup at UHF, the insane data rate and the distance (>100miles) were going to make reception difficult, so I was pleased I did manage to receive telemetry and image packets.

 
Most of the current LoRa development in the HAB community has tended to be on the Raspberry Pi due to the use with SSDV and the easy availability of cameras and ready built kit. LoRa is of course available on the Arduino platform and I had purchased a couple of 'Dragino' shields (pictured below) with a LoRa device on.


Dave has done some work on a AVR tracker software and a simple Arduino 'Serial' LoRa receiver. The receiver connects to a host PC appearing as a serial port and by running some gateway software the receiver can be configured via the serial link and received data is sent back to the gateway to be uploaded to the Habitat tracking system and SSDV system - the software can be seen here during the 'Operation Outward' test flight.


This gateway software is written in Pascal using Delphi and is not as functional as the Raspberry Pi Gateway software. Dave has made the source code available but I am not au fait at all with Delphi however I installed the free development IDE and intended to get in and make modifications but it seems to require a non-free(?) library for the serial comms so ditched the idea.

Instead I have spent the last few days developing a C# .NET version using Microsoft Visual Studio (the community version is free) and also have been modifying the Arduino code in the receiver to add functionality, such as storing the SSDV images locally.

It is still a work in progress but I have made a video showing the current state


Anyway as Cilla Black would say it's been a Lorra Lorra Laughs!


Latest antics

Here I am a month after the last post and it is has been a month of very little 'radio antics'.

I was acutely aware that since the end of September my wife had become a radio widow so promised not to lock myself away in the shack for a while and have been doing some much needed painting and decorating around the house.

I haven't been in much of a radio mood anyway as I have been unwell and am still not fully over my last wobble. Band and weather conditions have been rubbish with a sustained period of high wind and rain including storms Abigail and Barney. As a precaution I dropped the pole and it became apparent I had some maintenance to do on the OCFD.


The shack too had been in need of some sorting out, which I thankfully I did muster enthusiasm to tidy up.


While being largely uninspired I haven't been completely radio silent, I did get on air for the South Kesteven ARS 2m net but found myself suffering some QRM again


It isn't the first time I've seen this sort of signal, but I had thought it had gone away, it seems it is back and stronger! This was an ARISS contact I monitored back in 2013 before I was licensed with a similar noise.


After using the SDR to identify the noise I realised I have been neglecting the FUNCube Dongle for far too long. So ordered some new SMA adapters from HamGoodies and pressed it back into service. I have been using it to decode the telemetry from the FOX-1A (AO-85) satellite with the updated software and have now got myself on the leader board even if the collinear is currently horizontal about four feet off the ground!

South Kesteven ARS had a talk in October by Sean Burton 2E0ENN about amateur DMR where he demonstrated some handsets and the new DV4Mini which allows gateway and internet linking.

I remembered I dabbled a few years ago with decoding PMR DMR using the SDR and a scanner with a discriminator tap using various programs but they were very hit and miss at the time. I reacquainted myself with the various projects and had a go at decoding some amateur transmissions.

I downloaded the latest program called DSDPlus  (support at RadioReference.com) and monitoring the nearby GB7RR DMRPlus repeater managing to get some clear decodes with little effort.


Finally this week I gave a presentation at SKARS on the subject of HABs and how to plan a HAB launch. Following on from the Eggsplorer-1 and Hamfest "Pigs In Space" HAB launch I decided to try to explain everything I had learned for anyone else contemplating giving it a go!

It was a long talk (perhaps too long) as I covered everything from building the electronics, software, making the payload box, getting the right balloon, parachute, gas, obtaining permission and then the prediction, launching tracking and recovery.



It was a great turnout with a lot of interest.

Latest antics

Here I am a month after the last post and it is has been a month of very little 'radio antics'.

I was acutely aware that since the end of September my wife had become a radio widow so promised not to lock myself away in the shack for a while and have been doing some much needed painting and decorating around the house.

I haven't been in much of a radio mood anyway as I have been unwell and am still not fully over my last wobble. Band and weather conditions have been rubbish with a sustained period of high wind and rain including storms Abigail and Barney. As a precaution I dropped the pole and it became apparent I had some maintenance to do on the OCFD.


The shack too had been in need of some sorting out, which I thankfully I did muster enthusiasm to tidy up.


While being largely uninspired I haven't been completely radio silent, I did get on air for the South Kesteven ARS 2m net but found myself suffering some QRM again


It isn't the first time I've seen this sort of signal, but I had thought it had gone away, it seems it is back and stronger! This was an ARISS contact I monitored back in 2013 before I was licensed with a similar noise.


After using the SDR to identify the noise I realised I have been neglecting the FUNCube Dongle for far too long. So ordered some new SMA adapters from HamGoodies and pressed it back into service. I have been using it to decode the telemetry from the FOX-1A (AO-85) satellite with the updated software and have now got myself on the leader board even if the collinear is currently horizontal about four feet off the ground!

South Kesteven ARS had a talk in October by Sean Burton 2E0ENN about amateur DMR where he demonstrated some handsets and the new DV4Mini which allows gateway and internet linking.

I remembered I dabbled a few years ago with decoding PMR DMR using the SDR and a scanner with a discriminator tap using various programs but they were very hit and miss at the time. I reacquainted myself with the various projects and had a go at decoding some amateur transmissions.

I downloaded the latest program called DSDPlus  (support at RadioReference.com) and monitoring the nearby GB7RR DMRPlus repeater managing to get some clear decodes with little effort.


Finally this week I gave a presentation at SKARS on the subject of HABs and how to plan a HAB launch. Following on from the Eggsplorer-1 and Hamfest "Pigs In Space" HAB launch I decided to try to explain everything I had learned for anyone else contemplating giving it a go!

It was a long talk (perhaps too long) as I covered everything from building the electronics, software, making the payload box, getting the right balloon, parachute, gas, obtaining permission and then the prediction, launching tracking and recovery.



It was a great turnout with a lot of interest.

Hamfest Balloon – Some analysis



It has been five days since PINKY and PIGLET had their successful flight into the stratosphere. I have been studying the telemetry data and the photographs. I am really pleased with them but it makes the failure of previous Eggsplorer-1 mission to get any wow images more painful.

I contacted some local and national newspapers about the flight but with little response. The Register IT news website did put an article on http://www.theregister.co.uk/2015/09/28/pigs_in_spaaaace

I checked out the telemetry statistics on http://habitat.habhub.org/stats/ and was impressed with the number of people who tracked (as can be seen in the pie chart below) I know that several interested parties have since visited the UKHAS wiki and have been asking questions on the IRC channel on how to do a flight and/or develop their own trackers. Naturally I have also been thinking about some possible future flights.


While the novelty of flying something into space, be it a toy pig or an egg is satisfying I would like to make any future flight serve some purpose, whether collecting more data or ideally doing some experiment with radio even if it within the constraints of the UK draconian regulations when operating in the air!

One set of data I did extract was the temperature profile during the flight. PINKY had two sensors, one internal to the Styrofoam box, the other external. PIGLET also had a temperature/pressure sensor but it was giving odd readings during the flight so have ignored that.


The graph shows internal/external temperature recorded by PINKY against altitude, there are two plots for each showing the ascent profile and the decent. The lowest temperature recorded by the external temperature was -49.5°C   (-57.1°F) and the foam did a good job of insulating the internal electronics, though it drop below 0°C during the decent.


One thing I will do on the next flight (if it happens) is take a lot more photographs, using a 32GB memory card I could have held a lot more images. Also I will look at embedding the GPS coordinates (geotagging) into the image files.

I will also put on board a video camera, I did purchase a cheap dash cam type for £20 one off eBay for the Eggsplorer-1 but didn't use it because of sea-landing, I need to sort out powering it as the internal battery wouldn't last for the duration of the flight.


I have still to investigate the issues with the LoRa as to why it failed. This weekend Dave Akerman is flying three balloons in succession with LoRa tracker modules. They will be set up to work in a mesh, receiving and repeat each others telemetry. Sounds an interesting experiment, I will have to set my LoRa gateway back up and attempt to receive them.


Hamfest Balloon – Some analysis



It has been five days since PINKY and PIGLET had their successful flight into the stratosphere. I have been studying the telemetry data and the photographs. I am really pleased with them but it makes the failure of previous Eggsplorer-1 mission to get any wow images more painful.

I contacted some local and national newspapers about the flight but with little response. The Register IT news website did put an article on http://www.theregister.co.uk/2015/09/28/pigs_in_spaaaace

I checked out the telemetry statistics on http://habitat.habhub.org/stats/ and was impressed with the number of people who tracked (as can be seen in the pie chart below) I know that several interested parties have since visited the UKHAS wiki and have been asking questions on the IRC channel on how to do a flight and/or develop their own trackers. Naturally I have also been thinking about some possible future flights.


While the novelty of flying something into space, be it a toy pig or an egg is satisfying I would like to make any future flight serve some purpose, whether collecting more data or ideally doing some experiment with radio even if it within the constraints of the UK draconian regulations when operating in the air!

One set of data I did extract was the temperature profile during the flight. PINKY had two sensors, one internal to the Styrofoam box, the other external. PIGLET also had a temperature/pressure sensor but it was giving odd readings during the flight so have ignored that.


The graph shows internal/external temperature recorded by PINKY against altitude, there are two plots for each showing the ascent profile and the decent. The lowest temperature recorded by the external temperature was -49.5°C   (-57.1°F) and the foam did a good job of insulating the internal electronics, though it drop below 0°C during the decent.


One thing I will do on the next flight (if it happens) is take a lot more photographs, using a 32GB memory card I could have held a lot more images. Also I will look at embedding the GPS coordinates (geotagging) into the image files.

I will also put on board a video camera, I did purchase a cheap dash cam type for £20 one off eBay for the Eggsplorer-1 but didn't use it because of sea-landing, I need to sort out powering it as the internal battery wouldn't last for the duration of the flight.


I have still to investigate the issues with the LoRa as to why it failed. This weekend Dave Akerman is flying three balloons in succession with LoRa tracker modules. They will be set up to work in a mesh, receiving and repeat each others telemetry. Sounds an interesting experiment, I will have to set my LoRa gateway back up and attempt to receive them.



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