Lasers and Canberra Weather

I took the CNC to school today to show to my electronics class and some teachers. A lot of people were really interested in the nice spirograph drawings it produced. They were also amazed at how accurate it is. One teacher even gave me a nice fine tipped pen for it to draw with. It produced much finer lines than just a standard ball point pen. Here’s some prints from today.

Same program done two times at different start points. Ran out of time so the outside circle wasn't finished.

Same program done two times at different start points. Ran out of time so the outside circle wasn't finished.

 

This one stuffed up because the paper was crinkled.

This one stuffed up because the paper was crinkled. And someone kept banging the table.

Probably the best print of the day.

Probably the best print of the day.

Okay so the print quality is only getting better. But drawing things with pens is a bit pointless. That’s what a normal printer is for. So that’s why I want to get a laser. But this is problematic. Yesterday I tried to get some lasers out of some old CD drives. It worked but the lasers only emitted weak invisible infrared light. Infrared lasers are dangerous as their beam cannot be seen. And the lasers were not powerful enough to burn wood. So they were not a solution. The CD drives did however provide useful magnets to hold down the paper. These magnets were superseded by some rare earth magnets from the school electronics lab.

The aluminium build platform with the rare earth magnets.

The aluminium build platform with the rare earth magnets.

But I still have a problem with the lasers. It appears that the only way to get decently strong lasers is by getting them out of old blu ray drives. Here’s an example of the power of a blu ray laser:

But blu-ray drives are hard to come across. As are powerful off the shelf lasers in Australia. Hmmmmm. I’ll have to look around to find an old blu ray player. Once I have a laser I can cut out sculptures etc. Which was the whole point of building this thing.

Balloon

The balloon is at a bit of a standstill at the moment. My electronics teacher said he went to the top of Red Hill and watched how far the high altitude clouds go in 15 minutes. He said they went north east and disappeared within 15 minutes from horizon to horizon. So Canberra may not have the right high altitude conditions to launch it. It could get blow way north where we couldn’t retrieve it. So I have to think about that. Or not go ahead with the build. ūüė¶

So that’s about all I have to say for now. Right now I’m doing exams for school so I’m a bit busy. Hence the low amount of blog posts. But do not fear, I only have exams for the next week and then I’ll have heaps of free time. There’s even a review of the element 14 XL star dev board on its way.

Oh yeah and Bill if you’re reading this I just wanted to say (because I forgot to today) that I’m willing to help you out with getting started in Arduino. I know how confusing it can sometimes be.

 

 

 

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Well, well, well

A lot has happened recently. And I mean a lot.

So what have I been up to? Well a lot of stuff as mentioned above.

One of the most important things that has happened recently for me is I’ve been hired. No, not by Macdonalds like half of my school it seems. No, I’ve been hired to create the new website for uavs australia. If you don’t know who they are here’s their current website:¬†http://www.uavsaustralia.com/¬†. Trust me, I’m making a better one than that. So I’ve been dusting off my web coding skills and hitting the aptana studio editor hard. So I haven’t had much time to write stuff for this blog as frequently as I normally do.

The other thing I have been doing is building a spacecraft. The avionics are nearly done (I’ll write something up on them when they’re finished) and I have figured out the whole government approval thing. All I have to do know is get a balloon and some helium. Kids at school just laugh when they ask me what I’m doing on the weekend. “I’m working on a spacecraft”.”Bulls**t you are”.

Yesterday I did some testing of the balloon video camera by strapping it to a kite for a high speed test run. Here’s a still from the flight.

I'm the little dude in the white jumper.

I’ll upload the full video some time. It makes for interesting viewing. The kite can get a pretty high perspective.

I also flew some water rockets using a hose and some bottles with a friend. We got a bit bored on a Sunday afternoon. Here’s a couple of pics from that adventure:

The rocket could fly to about the distance of the car in the background. I mean it was just a bottle shoved on a hose.

The rocket could fly to about the distance of the car in the background.

That's my friend kicking a dud one to get it to launch.

That's my friend kicking a stubbourn one to get it to launch.

Sorry the rocket pictures are so low res. My friend has go pro footage of the launches. I’ll have to get it off him. It was fun and wet launching those things. You pinch the hose as a throttle and gradually build up the pressure in the bottle until it can’t take it any more and blasts off.

So there’s my hastily written update on what I’ve been doing. I’ll keep you posted.

All systems are go.

This near space weather balloon thing is getting exciting.

the view of planet earth.

The photo above is of the view of Canberra from the proposed 27km altitude that the balloon will reach. Lake Burley Griffin looks like a puddle. I can’t wait to see this from a camera I flew into space myself.

Today I was talking to my electronics teacher about the project and he said that he wanted me to do all of the electronics and leave the balloon bit to him. So that’s exactly what I’m doing. The plan with the electronics is to do the first couple of flights with an android smart phone for the brains and tracking and then gradually move away from that to a more complicated system (using home brewed avionics). While I’m building the first version of the balloon with a smartphone and a spy camera I’ll work on some more elaborate systems using proper chips and electronics. What I hope to have by a couple of weeks or months is a fully functioning tracking and USB hosting development board specially made for the purpose. I’ve already started the design with an atmega328 as the core. I might also design a PCB.

But while I design a better system I still have to get the first version up in the air with the android phone system. The main problem with this project is battery life. From what I’ve read, balloon flights can last anywhere from 3-5 hours. That’s a long time for my smart phone to be turned on and a very long time for my little spy camera. The little spy cameras only carry a small battery with around 300mah of capacity. That translates into around about an hour of recording from what I’ve heard. My phone isn’t much better. It will last about a day if I use it a lot to read other blogs and play games at full screen brightness every now and again. That’s probably about 3 hours of solid use. However, it will last for many days if the screen brightness is turned down and it is not using too many wireless functions.

I remember reading an article in the newspaper (can’t remember which one) a while ago about conserving smartphone life. It said that some of the most power-hungry functions on a phone are GPS and 3G internet. Yeah well, I’m using those constantly and heavily. Looks like I’ll need an external battery source for the phone and the spy camera.

I could go all hacker and solder another battery to the existing connections inside my phone and spy camera but I don’t really feel this is the way to go. The first reason is that it is incredibly easy to fry a phone or spycam by doing this. I tend to fry things because I just plug them in without thinking too hard. Remember my Leanlight project? I blew up two 7805 voltage regulators in that because I wired up the battery the wrong way round. Then I decided it might be time to stop desoldering dead regulators and solder in a protection diode. The second reason for not soldering a battery directly to the device’s existing battery points is that it just looks messy. It’s ugly having an RC plane battery hanging out of a phone or spycam with its case half on. Not neat engineering design. Besides, building a simple dual output USB supply is useful for powering a lot of things that don’t have good battery life on the go (like GoPros etc). Also, a USB power supply can power a dedicated avionics dev board easily with the 5V it will require (I’m going with the good old atmega328 for the dev board and it takes 5V).

For the power supply I decided to simply build two of the Leanlight power supply units on the same board with some modifications. One of the most important things was that I had two of them. Why did I want two when I could just wire both devices up to the same power output? Backup. No-one can hear your 7805 voltage regulator blow up in space. Another important addition was a protection diode. The last thing I need is a 7805 blowing up just when I connect the batteries the wrong way round minutes before launch.

Here’s a pic of what the power supply circuit is. The actual power supply circuit will be a lot more tightly packed. It’s just spread out so you can see the layout.

click to enlarge

click to enlarge

It is important to remember that this version of the balloon is designed to be simple. I might add some LEDs with some test switches so I can easily see without a multimeter whether the balloon’s electronics power supply is working.

So I’m going to build that power supply board on Friday afternoon or Saturday. Then my electronics work is finished and I can start designing a dedicated dev board. I’ll have to test it in the cold conditions of near space at -50 degrees celsius. I’m going to need a freezer. Maybe the school’s kitchen’s one. Or maybe just mine. I wonder how cold mine gets. Hmmmmm.

Until next time, check out these vids:

 

 

Space balloon.

Ever since around about the end of 2010, I’ve wanted to build a near space weather balloon project like this one:¬†http://space.1337arts.com/¬†. And I haven’t.

Well, you say, aren’t you lazy Lochie! Get off your bum and do what you want to do. So I am. It is now that I announce to you my grand plan.

My plan

Most weather balloon projects are incredibly complicated. They usually involve individual tracking, communications and¬†data logging¬†boards. And at least a handful of arduinos and wires. Well, I’ve decided to keep to the keep it simple stupid (KISS) concept with this one. The only bit of custom electronics will be a USB power supply. The main brains of the project will be a cheap Huawei X1 smart phone. They’re cheap, run android and are small and light. These are all really useful things. It’s really important that something like this is kept cheap for a couple of reasons:

  1. I’m a cheap kind of guy. I guard my money closely.
  2. Balloons don’t always come back.
  3. And when they don’t come back they are often just sitting in the little “to be sold on ebay” stash of some guy. He’s more likely to give it back to you for a reward the cheaper it is.

The project will also have on board a small spycam that I showed off in my previous blog post. It is also light, cheap and hackable. This balloon is going to be pretty awesome.

The Phone

The phone is going to be a Huawei X1 purchased from Optus for $71. It will handle the tracking and communications side of things as well as taking some pretty pictures. The phone will be loaded with the Real Time GPS app along with the IP webcam app and the where’s my droid app. Real Time GPS will supply the tracking and where’s my droid will act as a backup tracker. IP webcam will be used to provide a kind of live stream of events. The phone will have external power via USB and some RC plane batteries. The main reason that I am using the Huawei X1 is that I already own one so I can test tracking etc (it’s been working so far) before buying another one for the project. I’ll¬†also¬†probably have to crack it open to solder in an external antenna for better range. Or I could just use my current one and take the risk. I do like my phone though…..

The Camera

See here.

The Power Supply

I’ll be using a similar circuit to the one I used for my Leanlight project. There’ll be an individual power supply for each device as shown below.

click to enlarge

click to enlarge

As for the balloon and parachute, I’m not really doing that bit. I’m doing this with my electronics teacher and he’s figuring that stuff out. Once I’ve built the power supply for the electronics and done some testing, the balloon and parachute rig should be ready.

So there you have it. My rushed and rough explanation of what I’m building. There will be more. I promise. I’m sorry I don’t write as much for the blog as I have been the last few weeks. It’s just that I have to go to something pesky called school now, whereas before I was on holidays.