SVC_PI_SKY - A near space adventure (part 2)

Planning

We were determined to launch in just 5 weeks (we'd ideally aim for 3-6 months next time), before the end of the school year and as such some of planning was quite rushed. We had tons of help from Dave Akerman, Anthony Stirk, and the UKHAS community. This website is a great place to begin you near space journey. They have far more detailed guides to all parts of the process and they also have an IRC channel which is a great source of support.

Permission

I've put this right at the top as it is crucial and you cannot launch without it, permission must be obtained from the Civil Aviation Authority (CAA) who will issue you with a Notice to Airmen (NOTAM). This has an impact on where and when you can launch, if your predicted flight path takes you over airfields or lands in built up areas you will not be able to launch.

A payload

This is the box or container that would be sent up, containing all the electronics etc. It needs to be as light as possible  (ours was about 800g) and fairly strong.

A balloon and parachute

A helium filled weather balloon is needed to lift the balloon to high altitude where it will burst and then the payload "glides" back to earth under a parachute. The exact parachute and balloon are dependent on the mass of the payload and desired altitude. We also needed a container of helium to fill the balloon.

A tracker (or two)

A tracker is a device which uses a range of sensors to gather data about the payload including GPS, temperature and power. It then combines this data into a small data packet which it transmits over radio waves back down to earth. These trackers are often hand made and programmed. However we decided to use an add on board for the Raspberry Pi called the "Pi In The Sky" (PITS) board (see my previous post). On the day of the launch Dave Akerman came to support us and actually sent up a spare tracker as a backup with ours.

A Ground Based Receiver

In order to be able to track the payload from the ground we needed something to receive and decode the radio signal from the payload. This data can then be plotted onto a mapping service and allow to to track the position. Although we didn't actually need our own tracker (we could have relied on the HAB community who could have tracked it for us) we were fortunate enough to have a HAM radio enthusiast at school who was keen to be involved.

A Mobile Receiver

A ground based receiver is great for general tracking but once the payload returns and is below a certain altitude it below hard to track. Some HAB (High altitude ballooning) enthusiasts have a receiver set up in their car which allows them to follow the payload throughout it's flight and landing.

A Camera

Obviously if we wanted to get images then we'd need a camera to capture these images, we also considered the possibility of capturing video using a small separate video camera. The Pi Camera was the obvious choice for the stills, however despite finding a small low cost camera to video the flight, it failed the day before launch!

In the next entry I'll be talking through how we setup and tested the PITS board.

SVC_PI_SKY - A near space adventure (part 1)

Way back in July in the last breath before the summer holidays a small group of students from Soham Village College in Cambridgeshire launched a Raspberry Pi project to near space. A video of the flight can be found here. The experience was awesome, everybody involved was absolutely buzzing before, during and after the flight. In my 10 years as a teacher it has to have been one of the single best days in school!

We got some much media back from the flight it was incredible, here is a short video which shows some of what we captured.

Inspiration:
Like so many projects this one was born from an idle conversation over coffee between myself and a fellow teacher. We'd seen some of the flights carried out by Dave Akerman, without who this project would not have succeeded. The conversation went something like this:

Teacher : Hey James, you're into Raspberry Pi. Did you see someone sent a potato into space with one the other week?

Me : Yeah that looked cool, there's been a few projects that have gone to space.

Teacher : How difficult do you think it would be to do that?

Me : Ummmm dunno, would be fun though.

Teacher : Think we could do something like that for SVC day? (4-5 weeks away)

Me : Sure, let's do it!

And it was with this level of care free optimism that our project was born.

I should explain at this point that SVC day is a brilliant day our school runs towards the end of the year in which the students get involved in various projects run by our teaching staff.

Our aims were no more lofty than trying (and probably failing), having some fun, and in the unlikely event that all went well, getting a single image back from space.

In this series of blog posts I hope to document what we managed to achieve (and the many mistakes that we made) so that anyone looking to do something similar might avoid these mistakes.

Github in the classroom new episodes

This last week has been manic, however I've done a couple of quick videos suggesting how Github can be used to set and mark / feedback on work.

How to create a simple repository for your students to work from:

How to submit and feedback on work:

Pi in the Sky Board (Unboxing)

In a little under a month our school are hoping to launch a high altitude balloon project into near space. Currently the aims of the project are quite simple:

• Launch the payload.
• Reach near space.
• Get a great picture.
• Hopefully, track and recover the payload.

Whilst looking at a variety of projects online (mainly from Dave Akerman) www.daveakerman.com we found that Dave and Anthony Stirk of HAB supplies (ava.upuaut.net/store) were developing a Raspberry Pi add board.

The board contains all the hardware required to track telemetry of the device and transmit it over UHF.

We received a prototype board in the post today, and we were very excited.

Github Education - Setting up an organisation (episode 2)

This next short video shows you how to create a an organisation for you class or school and where to apply for free private repositories

Github in education (episode 1)

I wanted to start documenting some of what I'm doing with Github in the classroom. Github isn't particularly challenging to understand once you've understood the basics.

Video is pretty basic, please comment to help improve it, I'm hoping to produce some more in the next few days or so.

Testing squish sensor

Just a quick post, I've tested the sensor I built yesterday with scratch gpio. Works well and send quite responsive and springy.

Raspberry Squish (building the sensor)

Today I found myself having a free hour or so I thought I'd remake my squish sensor. 5 mins later I'd been to the local shop to pick up some paper plates and I was ready to go.

Step 1 - Make cardboard base

The cardboard shown is just the flap from an old cardboard box, draw round the plate and cut out.

Step 2 - Tin foil contacts

Fold in half a sheet of tin foil, draw a circle the size of the base of the paper plate.

I drew round a bowl.

And cut out (carefully)

Step 3 - Wiring the contacts

Take a length of wire (I went with about 2m, to give me plenty of range for my sensor). Here I used speaker wire as it's got 2 wires joined together. I then split the wires apart by 10cm and stripped the ends.

Splaying the wire out, tape it down to the Centre of the tin foil.

Step 4 - fixing the contacts

Using PVA I glued the tin foil to the paper plate and to the cardboard.

I then realised the foil was larger than it needed to be for the plate, so trimmed this one.

Step 5 - putting it all together

With the two halves made we now need to fix them together, I simple used a few pieces of sellotape.

There we go a finished squish sensor!

Github in the classroom

I recently decided round to finally get round to investigating github as a tool to use with students. I'd played around a little last yeah contributing (albeit in a minor way) to the NOOBs project. I put together a utility script for converting raw customised images to NOOBs compatible images (https://github.com/mr-minifig/Pi-Noobs-Converter)
Originally I wanted to look at its potential as a backup solution for pupils work on their Raspberry Pi. Whilst this is something I want to pursue I soon became distracted by it's potential use as a platform to build students portfolios of coding and a record of their progress.
I set about testing this idea with one class creating a simple code improvement exercise, the idea being they would copy the code edit it and resubmit. The coding isn't particularly challenging as I wanted something that all students could access and complete with ease. When complete the students could "commit" their changes to the github repo and send the code back to me via a "pull request". (once i've gotten the hang of this I'll perhaps write a fuller explanation of he process.)
When students submit their code you can clearly see the changes they have made, including deletions (red) and additions (green). As a teacher I can then leave a comment for the student to respond to, or provide some kind of feedback.

I've only just started using github but am excited about what it could do for my students learning and for my ability to monitor and assess them. Some of the benefits of github (as I see them) include:

• Students can build a portfolio of their own work and abilities.
• Students can comment on each others work and suggest improvements
• They a participating in a wider community of coders and some may get involved in 'real' projects.
• Students work is easily visible to the teacher and also publicly visible (by default)
• Feedback and comments and assessment practices can be transparent and open to feedback.
• Students could model 'real' code development and begin to work in coding teams on one solution.

Raspberry Squish

I was lucky enough to be able to attend the Cambridge Raspberry Jam this weekend. It was an excellent day which left me buzzing.

One conversation during the #picademy session stuck in my mind, someone asked a question about getting the kids doing something physical with the raspberry pi and programming. We also spoke a little about buttons and switch and the electronics side of things.

This got me thing back to a CAS workshop run by @megjlow on physical computing with scratch and a picoboard.

The workshop was great and it really stuck with me how easy it was to create your own sensors from every day items, I was inspired to go home and create a pair of squish sensors out of some paper plates cardbaord and tin foil. We then wrote a little game in scratch where the player had to sit on the sensor as a raspberry moved past.

Unfortunately the sensors did not last more than a few terms before needing repair, but hey they cost pennies to make. I now want to go back to this idea and see if I can make a nice little primary activity. Anyhow he's a rough sketch of what it looked like (I've replace the picoboard with a raspberry pi).