Launch Announcement - Brightwalton - Sunday 26th May

[David Akerman]

Early warning that I'm hoping to launch on Sunday.  That's one of the days that BABSHAB might be launching, and uses the same frequency, but that's at silly-o-clock in the morning and mine won't be :-)

Mine has a pair of NTX2s so it'll use both .075 and .650.  If that gets in anyone's else's way let me know please - I could possible disable one channel.  However I'd like to know sooner rather than later.

This is a Pi flight running SSDV again.  Predictions are good for a normal "up - burst - down - recover" flight so that's what I'm hoping to do.  It's a lightweight payload and a Hwoyee "burst when it feels like it" 1600 so could potentially get quite high, so should bring in listeners from a fair distance away.

At the moment both channels are running 600 baud but I may change that - I'll let you know closer to the time.

Meanwhile:

Callsign: PIE

434.075Mhz and 434.650MHz

600Hz shift

600 Baud

8 bits no parity 2 stop bits

I'll run the batc live video stream from the launch site and chase car.

If anyone local wants to come along and help/watch they're very welcome.

Dave

[David Akerman]

Just confirmation that this flight is expected to go ahead as planned.  Launch time noon-ish which probably means 1pm.

The flight is "PIE6", and is the flight I was going to do last time before the predictions suggested a floater would be a better bet (and it was!).  This is the payload - http://www.daveakerman.com/?p=1005.  The electronics and firmware are essentially the same as for that flight, except that Tx is at 600 baud, the pi has been stripped of anything that wasn't being used, and there are no "special" images on board!

It's a lightweight payload and it'll be a 1600g Hwoyee with H2.  You can probably guess what I'm aiming at here.

I'll have the batc video stream running from the launch site, for added amusement.

Dave

[Oliver de Peyer]

How did you strip it? 
Given the ubiquity of the Pi and its low price now, I had often thought it might suit me but I didn't forsee a need for HDMI at 100,000ft etc! Things like BeagleBoards have less components but a higher price. So a stripped-down Pi I would be very curious about.

Thanks

Ol

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[David Akerman]

I removed all the connectors.

[David Akerman]

er except for the SD card holder :-)

[go.ver...@googlemail.com]

So you just snipped them off and it all still worked?

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From: David Akerman <da...@sccs.co.uk>

Sender: uk...@googlegroups.com

Date: Mon, 27 May 2013 15:02:38 +0100

To: <uk...@googlegroups.com>

ReplyTo: uk...@googlegroups.com

Subject: Re: [UKHAS] Re: Launch Announcement - Brightwalton - Sunday 26th May

[David Akerman]

Snipped/desoldered as I saw fit :)

[Steve Aerospace]

How much difference to the weight did it make?

Steve

Steve Randall

Random Engineering Ltd

st...@randomaerospace.com

+44 7802 242135

[David Akerman]

Down from 31g to 20g IIRC.  Not a massive saving and I'm not sure I'd recommend it generally.

Dave

[go.ver...@googlemail.com]

Do you have a list of what you did to what? It seems like a very good idea for anybody who needs a cheap basic computer with linux etc without all the tinsel of bits and pieces.

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From: David Akerman <da...@sccs.co.uk>

Sender: uk...@googlegroups.com

Date: Mon, 27 May 2013 15:31:45 +0100

[David Akerman]

No, I just looked at each connector in turn to see what was the safest option.

Unless it's a very light payload, it's really, really, really not worth it.  In my case the total weight was just over 100g excluding batteries, so even then it's hard to argue a case to chop bits off the board.

Remember also that if you do remove everything, you need a second board for development, as you won't be able to login to it.

[Steve Aerospace]

11g - I'm sure you did a lot better saving battery weight through power reduction.

Steve

[David Akerman]

Oh, much better.  The model A uses about 1/4 that of the model B, and the Pi camera uses less than a webcam.  Plus, with no USB devices, there's no need for a 5V line so I ran it from a 3.3V regulator (a real LDO not the rubbish one on the Pi) meaning it can run happily on 4 AAAs.  That's about the same runtime as my first Pi flight, with a battery saving of nearly 60g.

Dave

[go.ver...@googlemail.com]

If I ever get round to doing this properly, please may I drop you a line about how to trim a Pi or two similarly?

For what it's worth here is another family of stripped-down linux boards that had caught my eye, in the same format as a DIMM memory card:

http://www.eurotech.com/en/products/embedded+boards/so-dimm+boards

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From: David Akerman <da...@sccs.co.uk>

Sender: uk...@googlegroups.com

Date: Mon, 27 May 2013 16:03:07 +0100

[David Akerman]

Sure, but my advice then and now is "don't bother!"

Dave

[David Akerman]

Write-up here: http://www.daveakerman.com/?p=1154

Dave

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[David Akerman]

It certainly can.  Bit busy today but I'll do it sometime this week.

Dave

On 28 May 2013 09:17, GMT <graham....@virgin.net> wrote:

Dave,

On Monday, 27 May 2013 23:02:02 UTC+1, David Akerman wrote:

Write-up here: http://www.daveakerman.com/?p=1154

Dave

Your write-up/blog has the photo showing the Devon and Cornwall area ... is it possible to work out where it was taken from using the date/time of the photo, and maybe work out where the balloon was at the time it took the photo. It would give an interesting perspective to the photo .... something like "this is what Devon and Cornwall look like from 100,000 ft over Swindon" or whatever.

The same could be done for the other pic, the one showing the Isle of Wight.

Graham/G6SUQ

[David Akerman]

OK, for those 2 photos:

Isle Of Wight was at 13:55 UTC, taken at 21km up and a few miles SW of Wantage.

Land's End was at 14:46 UTC, taken at 38.9km up and directly over Westlea which is where I was reunited with the payload!

Dave

On 28 May 2013 09:17, GMT <graham....@virgin.net> wrote:

Dave,

On Monday, 27 May 2013 23:02:02 UTC+1, David Akerman wrote:

Write-up here: http://www.daveakerman.com/?p=1154

Dave

Your write-up/blog has the photo showing the Devon and Cornwall area ... is it possible to work out where it was taken from using the date/time of the photo, and maybe work out where the balloon was at the time it took the photo. It would give an interesting perspective to the photo .... something like "this is what Devon and Cornwall look like from 100,000 ft over Swindon" or whatever.

The same could be done for the other pic, the one showing the Isle of Wight.

Graham/G6SUQ

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