The tile floor is half installed, and insulation is probably next on the list. The trailer is a vending trailer with a big side door, and already equipped with AC power and lighting. This project is going to take months to finish.

I’ll post some photos soon.

The Altus Metrum TeleDongle

Bdale Garbee and Keith Packard are both longtime Debian Developers, and have a pile of code to their credit. They’ve presented at a number of conferences and almost always find a way to work their passion for rocketry into their presentations. They are both amateur radio operators.

At the Linux Collaborative Summit last week, I had a chance to talk with them, and the topic drifted quickly to Rocketry and Amateur Radio, and the intersection of those interests. They’ve created the TeleMetrum telemetry system, available soon from their Altus Metrum site. This is an amazing platform that has applications beyond rocketry – a GPS, accelerometer, and altimeter with a telemetry link in the 70cm amateur band. it’s all open hardware and open software.

They’re about to open shop and start selling these, and I know it’s going to be a big deal for a lot of people in Rocketry. I can also see uses for high altitude balloon launches.

I’m not into rocketry any more, and there’s no room in my hobby load for that, but I was really interested in the programmable radio chip that they are using. The same chip is used on both the rocket and for the ground station, and the ground station unit is available as the TeleDongle. The TeleDongle is a complete radio system with 10mW output on the 70 cm band, powered from a USB port. As supplied, it has code installed from Keith which makes it a virtual 38k4 serial link. With different output filter values, the chip can function over a wide range of frequencies, but it’s only certified in certain bands. I’m still digesting the data sheet, but there’s an amazing amount of functionality on the chip.

Happily, I was able to order a couple of the TeleDongles from Bdale, and I got notice today that he has shipped them. They’re set up so that you can use one as a USB adapter to program the other, making experimentation easier. I’m looking forward to experimenting with these. I’ll post the results!

Applications shown will include:

fldigi – sound card digital modem
xlog – a logging program
hamlib – rig and rotator control
xdx – dx cluster client
colrdx – another dx cluster client
gpredict – satellite pass prediction and information
splat – VHF/UHF propagation prediction using terrain data
antennavis – Antenna pattern modeling and visualization
xnec2c - Another antenna modeling application
gsmc – a smith chart tool
aldo – morse code trainer
xastir – APRS application which can use network or rf connection

And . . . A surprise demo that I think is very interesting. The success of that demo will depend on reception conditions at the meeting. If I can’t make a full-functioning demo I’ll show what I can.

The meeting is at the Huntsville American Red Cross Chapter house at 7:30.

Here is a map link.

Next Friday, March 5th at the same time and place, we’re going to be having an installfest to install Ubuntu Linux on your computers.

Two Drawdio kits from Adafruit Industries. These are fun little kits that make a lencil that generates tones when you draw, using the resistance of the graphite on the paper. You can see one already built at the Antitronics space – I’ll be there this afternoon.
Auction Info (pdf).

Two Introduction to Arduino kits and lessons. These each include an Arduino Duemlanove, some assorted extras, and a free lesson.
Auction Info (pdf).

Update: Here’s a link to some of the awesome artwork available at the auction.

I have to give a shout out for the people I ordered the case from – Leisure Pro. I ordered the case with less than a week to go before this trip, so I had it shipped second day via UPS. Leisure Pro called on delivery day and said “Your shipment was just delivered to us. We don’t know why, but since you ordered this second day you must need it in a hurry – what can we do to make sure you have it when you need it?”.

Wow – proactive customer service! They got the case to me in time, it holds the makerbot, a handful of tools, and a couple of pounds of plastic with no problems. And – it comes in under 50lbs, which makes the checked bag limit.

So the ‘bot is here at the Ubuntu Developer Summit, and is printing as I write.

Well, it had some software issues and then got set aside for more urgent projects (like the makerbot – oh yeah!).

As a reminder, it’s built around an Arduino Duemilanove with an adafruit ethernet shield and an Xport module.

Tonight I wasn’t sleep-inclined, so I dragged it out and dug in. I ended up having to dig pretty deeply into the Xport configuration and learn more about how it works, which was a good thing in the long run.

The problem turned out to be an error in the Xport configuration that I had copied from an arduino example sketch. The owner of that example’s been notified, and my arduino code works, so it was a good evening of hacking.

The XPort module is a pretty powerful thing. Here are links to product information and the user manual (pdf)

The power monitor now PUTs a request to the web server as it should. There is still a bug on the server side, but it will wait until another day.

It’s been nagging at me that this got set aside, so now I feel better. I think I’ll go get some sleep.

makerbot-in-the-wild-white-beauty

We had a great arduino class on Saturday – it went a lot faster than I expected, and I ran out of things to talk about pretty early. That may have been because we had relatively few problems getting the arduino development software installed for everyone. Cory was a hero for bringing the windows version on a CD, because the network bandwidth went to almost nothing just as we needed a copy.

I meant to talk more about the history of the Arduino project and about open source, but I failed to prepare and didn’t cover it well. Next time I’ll do better.

All the material we covered came from examples supplied with the arduino platform, and they worked for everyone. An unexpected moment that I really enjoyed was when I pulled out the Oscilloscope to show what the Pulse Width Modulated (PWM) signal looked like. This is definitely staying in the class. There were a few notes that I made on the whiteboard, and didn’t give anyone copies to take home. So that there’s no confusion about hooking up the extra parts from the class, I’ve reproduced those notes here on the wiki.

Cory also asked an interesting question about using the arduino to trigger a photographic strobe. I reverted to to bad engineering behavior, and forgot that this was an intro course, and gave an answer that was probably discouraging. I realized I had lost my way when I heard myself saying “interrupt driven”. I’ll attempt to make a topic out of this for this wiki in the next day or so. But – the important thing is to go ahead and try that idea – it’s really easy to mock something up with the arduino platform. In fact, here’s a posting by someone who has played with triggering a strobe, and shared his project. I love sharing.

If you want to take the class but didn’t get in, send an email
and I’ll schedule another one soon.

It’s on – an Introduction to Arduino Class

Where: Antitronics – Flying Monkey Arts Center
When: Saturday, October 3rd 4:30 – 7:00
Cost: $30 (for the things you get to keep)

Requirements:

Let me know in advance if you will be there.
You need to bring your laptop, let me know which O.S. you run.

I have in my hot little hands a stack of Arduino Duemilanove boards. For your $30 you will get one of those, a USB cable, a 9V battery clip with a plug, a couple of LEDs and resistors. and a potentiometer. I will not supply a 9V battery. You won’t need one for class – you only need one later if you want to run your project disconnected from your computer.

The goals will be:

1. To get the arduino software environment installed
2. To demonstrate the structure of a basic arduino application
3. To show how to read information from the real world
4. To control some simple outputs, including PWM (and an explanation of what the heck PWM is anyway).

We will not go into deep details of the AVR processor or any other technical aspects of the arduino and how it works — this is sort of an appliance operator’s view.

Arduino home: http://www.arduino.cc/
The Duemilanove: http://arduino.cc/en/Main/ArduinoBoardDuemilanove
The Software: http://arduino.cc/en/Main/Software

You are invited to go ahead and install the software before the class if you are comfortable with that. If you want the hardware early, just pay me and it’s yours. I should have the remainder of the items (battery clips) in by next week.

Registration is limited since this is the first class. I don’t want to end up overloaded.

The class is full

RSVP to info [at] antitronics [dot] com