Hi,
I have a budget of £1000 from the IOP and other sources in order to put a balloon into space. I was very pleased to discover that my preferred option (using a Rasp Pi) has supporting add on's. I have purchased a 'sense hat' as well as a 'Pi in the sky board' ( https://www.raspberrypi.org/blog/pi-in-the-sky-2/ ) . The PisB has a temperature sensor built in and all the communication functions needed for GPS/telemetry etc. whereas the 'Sense hat' includes far more sensors (temp./humidity/pressure + accelerometer/gyroscope/magnetometer).
So...Q ' Can both these devices be integrated with one Rasp pi (model A)? This would seem to be the perfect one stop shop for doing everything but both devices seem to attach directly to the pi board. In which case, would I need two Rasp pi's with some kind of link up?
The PisB has 'Sockets for external i2c devices, analog input, external temperature sensor' - what is an i2c device? How can this be utilised?
Be aware...I have never before owned a Rasp pi so this is all very new to me.
Any/all help most welcome.
thanks,
Mr Blair
Teacher of Physics
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sblair1290
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jamesrobinson
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Re: using Pi in sky AND(?) sense hat?
Hi,
The simple answer is yes. These two boards will work together, I flew an A+ with Sense and PITs boards in September last year.
At the time I used the PITs software to handle the GPS and telemetry transmission and ran a datalogger program to collet sensor data and write to a local file.
The simple answer is yes. These two boards will work together, I flew an A+ with Sense and PITs boards in September last year.
At the time I used the PITs software to handle the GPS and telemetry transmission and ran a datalogger program to collet sensor data and write to a local file.
Re: using Pi in sky AND(?) sense hat?
Yes the 2 boards work together. You need to have device tree enabled (which is opposite to our normal instructions) and that will then stop the DS18B20 temperature sensor from working, but this is easily fixed. See http://www.pi-in-the-sky.com/index.php? ... o-pi-board for more information.
Dave
Dave
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sblair1290
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Re: using Pi in sky AND(?) sense hat?
That's great news. I also wondered about the options for receiving communications on the ground. There seems to be three options mentioned:
> 'a TV dongle for £12 or so...with a £15 aerial'
> 'a 3G dongle'
> 'or tethered to a phone'
is this correct? Briefly, if money wasn't too much of a concern (I have £500 left) which option would be the best. I suppose by 'best' I would mean most reliable.
Lastly, there seems to be a lot of trust in the Rasp Pi setup with the Pits board not losing communication and therefor no second GPS module being needed. Is there much to be gained by having a second module or is this overdoing it? Normally I would always use 'belt and braces' approach when sending hundreds of pounds floating off into the sky!!!
Nearly there....just received a lot of my kit today. My S2 science club will be most excited!
ta,
Stuart
> 'a TV dongle for £12 or so...with a £15 aerial'
> 'a 3G dongle'
> 'or tethered to a phone'
is this correct? Briefly, if money wasn't too much of a concern (I have £500 left) which option would be the best. I suppose by 'best' I would mean most reliable.
Lastly, there seems to be a lot of trust in the Rasp Pi setup with the Pits board not losing communication and therefor no second GPS module being needed. Is there much to be gained by having a second module or is this overdoing it? Normally I would always use 'belt and braces' approach when sending hundreds of pounds floating off into the sky!!!
Nearly there....just received a lot of my kit today. My S2 science club will be most excited!
ta,
Stuart
Re: using Pi in sky AND(?) sense hat?
By far the most reliable, and the only option that will give you the balloon position throughout the flight, is a direct radio link from balloon to ground. This is what PITS does, using a suitable receiver (e.g. the TV dongle) on the ground. Those dongles need to be used with the correct aerial (not the one that comes with it) and ideally with a "HAB Amplifier", both of which will increase the sensitivity and therefore range considerably.
No GSM/3G solution will work above about 2000m altitude, so can be useful as a backup but not something to rely on. I add a second tracker of some sort if I'm flying several cameras.
Dave
No GSM/3G solution will work above about 2000m altitude, so can be useful as a backup but not something to rely on. I add a second tracker of some sort if I'm flying several cameras.
Dave
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sblair1290
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Re: using Pi in sky AND(?) sense hat?
I presume this would do the job.
HAB preamp:
http://ava.upuaut.net/store/index.php?r ... uct_id=136
(operating at 434MHz)
This GPS antenna
(http://ava.upuaut.net/store/index.php?r ... uct_id=119 ) is also available from the same supplier. Could this be attached to the TV dongle?
There is a bewildering array of choice for TV dongles and they don't look like they would easily attach to the coaxial cable shown for this GPS antenna. I will take (Dave's) advice and begin testing with a decent dongle and just some wire pushed in the end (of correct length of course). At least then we can get the software and other parts tested. Your opinion on the GPS antenna above an how it might compare to other options would be welcome. I have a project report from final year students at Strathclyde who built their own J-pole antenna ('zeppelin' antenna) with good instructions on how to build. That might be an interesting side project if we have time. Although time is in short supply!
cheers for now.
Stuart
HAB preamp:
http://ava.upuaut.net/store/index.php?r ... uct_id=136
(operating at 434MHz)
This GPS antenna
(http://ava.upuaut.net/store/index.php?r ... uct_id=119 ) is also available from the same supplier. Could this be attached to the TV dongle?
There is a bewildering array of choice for TV dongles and they don't look like they would easily attach to the coaxial cable shown for this GPS antenna. I will take (Dave's) advice and begin testing with a decent dongle and just some wire pushed in the end (of correct length of course). At least then we can get the software and other parts tested. Your opinion on the GPS antenna above an how it might compare to other options would be welcome. I have a project report from final year students at Strathclyde who built their own J-pole antenna ('zeppelin' antenna) with good instructions on how to build. That might be an interesting side project if we have time. Although time is in short supply!
cheers for now.
Stuart
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sblair1290
- Posts: 30
- Joined: Mon Feb 15, 2016 1:56 pm
Re: using Pi in sky AND(?) sense hat?
Having looked into some Dongle prices and specs I finally retraced my steps and a link http://airspy.com/download/ which led to the funcube dongle (http://www.funcubedongle.com/ )
The manufacturers claim this is specially adapted for retrieving signals from space ( http://www.funcubedongle.com/MyImages/F ... uction.pdf ).
After a quick read of this PDF it appears they were investigating the use of preamps in 2011 and no mention is made of what aerial should be used. Does anyone have any experience of this setup and is it a suitable option for a project of this kind (it costs £125 + taxes). This seems excessive if a £20 TV dongle can do the job. It seems that perhaps the funcube is a more versatile instrument (wider range etc). I am currently looking through their forum so I will post back if I learn anything new.
that's all for now though......
Stuart
The manufacturers claim this is specially adapted for retrieving signals from space ( http://www.funcubedongle.com/MyImages/F ... uction.pdf ).
After a quick read of this PDF it appears they were investigating the use of preamps in 2011 and no mention is made of what aerial should be used. Does anyone have any experience of this setup and is it a suitable option for a project of this kind (it costs £125 + taxes). This seems excessive if a £20 TV dongle can do the job. It seems that perhaps the funcube is a more versatile instrument (wider range etc). I am currently looking through their forum so I will post back if I learn anything new.
that's all for now though......
Stuart
Re: using Pi in sky AND(?) sense hat?
The GPS aerial isn't for the TV dongle. Perhaps I should explain how this all works ...
PITS H/W is a GPS module and a UHF radio transmitter, plus a power supply and a couple of sensors, on a board that plugs into the Pi. It comes with a GPS aerial and a UHF aerial. The PITS software then gets the position (latitude/longitude/altitude) of the device from GPS, and transmits the position plus sensor values down to the ground.
On the ground you need a UHF antenna and receiver so you can receive the PITS transmissions. You don't need a GPS antenna on the ground as you're not receiving GPS.
The receiver on the ground can be 1 of 4 basic groups of device:
1 - TV dongle (RTL-SDR). Anything with an R820 in it will work. These are a bit deaf and need the HAB Amp.
2 - A better SDR (e.g. Airspy, Funcube Dongle, SDR Play)
3 - Radio scanner that has SSB
4 - Ham radio transceiver that does 70cm SSB
Lowest cost is (1), but do get the HAB Amp; the combination should be pretty much as good as anything else.
Dave
PITS H/W is a GPS module and a UHF radio transmitter, plus a power supply and a couple of sensors, on a board that plugs into the Pi. It comes with a GPS aerial and a UHF aerial. The PITS software then gets the position (latitude/longitude/altitude) of the device from GPS, and transmits the position plus sensor values down to the ground.
On the ground you need a UHF antenna and receiver so you can receive the PITS transmissions. You don't need a GPS antenna on the ground as you're not receiving GPS.
The receiver on the ground can be 1 of 4 basic groups of device:
1 - TV dongle (RTL-SDR). Anything with an R820 in it will work. These are a bit deaf and need the HAB Amp.
2 - A better SDR (e.g. Airspy, Funcube Dongle, SDR Play)
3 - Radio scanner that has SSB
4 - Ham radio transceiver that does 70cm SSB
Lowest cost is (1), but do get the HAB Amp; the combination should be pretty much as good as anything else.
Dave
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sblair1290
- Posts: 30
- Joined: Mon Feb 15, 2016 1:56 pm
Re: using Pi in sky AND(?) sense hat?
Ok, we bought a Funcube Dongle plus a HAB preamp (see links above). In the end I considered that the Funcube dongle could be used separately for its intended purpose (Cubesat) or with our own balloon project. The HAB amp I bought in case we do go down the route of using a cheaper TV dongle for any reason. It may also turn out to be beneficial with the Funcube dongle? Our last consideration then is the actual aerial but we have a lot to do in the meantime with setting this lot up and plugging it in! We have several parts on back order unfortunately so until then........THANKS
Re: using Pi in sky AND(?) sense hat?
The HABAmp includes a band-pass filter, so will largely prevent frequencies other than the ones you are interested in from reaching the Funcube. If you're anywhere near a powerful transmitter then this is a good thing.
Dave
Dave
Re: using Pi in sky AND(?) sense hat?
We put the board on backwards from the pi and after fixing it we do not get any readings from the temp sensor, nor a gps lock. Does anyone know if we burnt out the board?
Re: using Pi in sky AND(?) sense hat?
It's not something we test so I don't know if you've damaged it.
We had someone else find an inventive way of putting the board on, and they didn't fry anything, but that's not to say that you haven't. We responded by putting "This way up" on the top and "NOT this way up" on the bottom. We also have a page at http://www.pi-in-the-sky.com/index.php? ... l-assembly to show the correct method.
The temperature sensor won't work with device tree enabled unless you make the change mentioned earlier in this thread, so that's a possible reason for that issue.
GPS lock does require that the GPS aerial has a reasonably clear view of the sky, and that it's connected to the GPS socket and not the UHF one (and yes, we have a page for that too - http://www.pi-in-the-sky.com/index.php? ... onnections).
If you think the board is faulty, you're welcome to send it back to see if it can be repaired.
Dave
We had someone else find an inventive way of putting the board on, and they didn't fry anything, but that's not to say that you haven't. We responded by putting "This way up" on the top and "NOT this way up" on the bottom. We also have a page at http://www.pi-in-the-sky.com/index.php? ... l-assembly to show the correct method.
The temperature sensor won't work with device tree enabled unless you make the change mentioned earlier in this thread, so that's a possible reason for that issue.
GPS lock does require that the GPS aerial has a reasonably clear view of the sky, and that it's connected to the GPS socket and not the UHF one (and yes, we have a page for that too - http://www.pi-in-the-sky.com/index.php? ... onnections).
If you think the board is faulty, you're welcome to send it back to see if it can be repaired.
Dave
Re: using Pi in sky AND(?) sense hat?
Thank you Dave for all the information, I am a Teacher in Peshtigo, and we have been working with the Pi in the Sky for that last couple of weeks.
We are at the point of troubleshooting the whole project to make it work.
P.S. we noticed the notes on the Pi in the Sky and laughed a bunch when we noticed the mistake.
Have a great day!!!
We are at the point of troubleshooting the whole project to make it work.
P.S. we noticed the notes on the Pi in the Sky and laughed a bunch when we noticed the mistake.
Have a great day!!!