First, let’s figure out the path to our serial device. Ubuntu typically places these devices at /dev/ttyUSB#. Use the following command to determine the appropriate number of your device.

$ ls /dev/ttyUSB*

Now we’ll install Minicom to get started.

$ sudo apt-get install minicom

Once that’s complete, we’ll need to configure Minicom so that it’s using the correct port. To do this, run the command below.

$ minicom -s

You’ll be prompted with a configuration menu. Arrow down to “Serial port setup” and press enter.

+--------------------------------------------------------+
| A -    Serial Device      : /dev/ttyUSB0               |
| B - Lockfile Location     : /var/lock                  |
| C -   Callin Program      :                            |
| D -  Callout Program      :                            |
| E -    Bps/Par/Bits       : 115200 8N1                 |
| F - Hardware Flow Control : Yes                        |
| G - Software Flow Control : No                         |
|                                                        |
|    Change which setting?                               |
+--------------------------------------------------------+

The first line will give you the path to the serial port Minicom is going to talk to. If this doesn’t match the /dev/ttyUSB# path you found above, hit “A” on your keyboard and enter in the correct path and press enter. Now double check your Bps/Par/Bits settings. The default 9600 8N1 is pretty standard, but you may need to hit “E” and provide a different Speed setting depending on the device you’re talking to. In my case, OpenLog is running at 115200bps, so I went through and made the appropriate changes. Hit enter again to exit the serial port settings menu. The other settings can usually be left to their default values, so arrow down to “Save setup as dfl” to save this configuration as default. This way you don’t have to configure Minicom every time you use it. Now arrow down to “Exit” and hit enter. Minicom will now start up using the settings you specified. If all goes well, you should now be connected to your device and ready to send/receive. From now on, you can start minicom without the -s switch.

$ minicom

Got a better HyperTerminal replacement that you use in Linux? Let me know about it in the comments.

I’ve been participating in autocross events for years and have always wished I could afford a data acquisition system like those you see used in Formula 1, Indy, Le Mans, and/or NASCAR. With a DAQ, I’d be able to see exactly what my car is doing at an event and use that information to help me drive the course faster on my next run. Hopefully.

That got me thinking. Surely I’m not the only amateur autocrosser wishing for an affordable data acquisition system made for the weekend warrior. In fact, LOTS of people across the nation, and across the globe would probably love such a system. I didn’t know of any that existed on a college student budget, so I figured why not make one? It just so happens this senior design semester is the perfect time to get started. But where to begin?

I began looking at professional systems to see what they were doing so I could get an idea where to start. After looking at a few of the products out there, most of them seemed to be doing some sort of GPS tracking as well as logging all the sensor data the user needs (or can afford). I started looking into using a USB GPS plugged into a laptop and use software to track and log the position data so the user could review it later. In the midst of looking for a GPS, I discovered most of the professional units were boasting GPS units with 5-20Hz refresh rates, but the units I found were all 1Hz. Hmm, I know I want to go cheap, but it also needs to do it’s job well. I had to find something better. I eventually stumbled upon a 10Hz GPS chip that sounded like it would do the trick, but how in the world was I going to get data off a lone circuit chip? I also want to use an accelerometer to measure precise movements of the car, but USB versions were expensive. Chip-only models were vastly cheaper, but how do I connect one to a computer? Time for some more research.

That’s when I met the Arduino.

So many possibilities in such a tiny package.

I think the Nintendo was the last time I used an 8-bit processor, but I have a feeling I’m going to have so much more fun with this thing! Could your Nintendo convert an analog voltage into a 10-bit digital value? I didn’t think so.

The Arduino Duemilanove is the latest board to come from the open hardware Arduino project. The beauty of Arduino is it’s openess and ease of use. The design schematics are openly available; ready for people to adapt and improve, or to integrate directly into their own projects. The microcontrollers used also come pre-programmed with the Arduino bootloader which makes it a piece of cake to write some code, plug the board in via USB, click a button to upload the code and make it run. The Arduino drastically lowers the learning curve necessary to start using a microcontroller.

With my Arduino, the possibilities are endless. This little board has opened the door wide open to this project and should be able to handle everything a motorsport data acquisition system should need. Now it’s time to fire this thing up and see what it can do! Stay tuned.

Or maybe not. I hopped into the #Sparkfun chatroom on irc.freenode.net the morning of Free Day to check out what people were chatting about. To my dismay, hours before the event started, there were already almost 700 people in the chatroom. According to Sparkfun’s limitations on the event, only 1,000 $100 orders would be awarded. The numbers were already daunting. I pulled up the Sparkfun website to find their recently updated web servers were already buckling under the load of people preparing their shopping carts. Uh oh. As time neared 11am, the chatroom hit the 1,400 user mark and my hopes of free electronics started to dwindle.

Minutes before the event, I went to my shopping cart, and prepared to click the Checkout button on the hour. 11am struck, my finger punctually tapped the mouse button, and my order request was on it’s way across the ‘tubes to Sparkfun’s datacenter in Colorado… Minutes later, the page timed out and I sent the request again, and again. As the minutes went by, so did the time outs and blank white pages across my screen. Scanning the chatroom, I saw reports of people successfully reaching the shipping page, ready to submit their Free Day order; still nothing on my screen. After an hour of failed attempts, I finally reached the log-in screen. Gah, I logged in just before the event started to avoid this! After providing my account info, I waited another 10 minutes and reached the shipping page. The taste of success was on my tongue as many before me reported their completed orders shortly after reaching the shipping page. I gleefully submitted my shipping information.

And that was the last I saw of Sparkfun.com. As I watched the Firefox throbber spin away, my heart dropped as people reported the giveaway totals nearing dangerously to the $100,000 limit. Before I could reach the billing page, SparkFun announced on Twitter that Free Day was officially over. And so were lost my dreams of free electronics. Sulked, I returned to the chatroom to read the flurry of exuberant posts from those who had successfully received their Free Day orders.

This story ends happily, however. Once the rush of traffic to Sparkfun’s site died down after the event, I was able to trim my bloated cart of electronic goodies to only that which I needed for my project, and proudly submitted my non-free order.

Thanks for the experience, Sparkfun.