Economy Size Geek - A Pico-Sized Platform with Potential
I saw a short video on YouTube about something called a Beagle Board, and it looked really interesting. It was this incredibly tiny board with plenty of ports. It even had an HDMI, which meant it would be easy to hook up to the LCD television in my living room. I put in my order to Digi-Key, and a few weeks later, it showed up. (I ordered it while Digi-Key was working on a new version, so your order should arrive faster.)
When the package arrived, and I pulled out the box, my first reaction was wow! This thing is tiny! When I opened the box, I realized that Digi-Key wasn't kidding by calling it the Beagle Board. The only thing in the box was a shiny red PCB (Printed Circuit Board). I had seen the board in the video, but until I got it, I didn't realize it came as a bare board. This led to my second order from Digi-Key. I didn't own the proper 5V power supply to make it work. I also added on a Beagle Board serial cable, which was lucky because it is an essential part of the setup process. I already had a serial-USB dongle, so if your computer does not have a serial port, you will need that as well.
The Beagle Board has a ton of features built in, with options to add on more. The main feature of the Beagle Board, besides its 3"x3" form factor, is the OMAP 3530 processor. This tiny ARM processor handles all the heavy lifting on the board. The rev C. board that I have even has an extra USB port that is not shown in the picture, making it even easier to hook up USB peripherals to the board. In my case, that would be a USB hub, keyboard, mouse, Wi-Fi dongle and a thumbdrive.
The Beagle Board was developed by a very small team of engineers inside Texas Instruments. TI has a “small dreams” program where employees are given some funding to pursue a good idea. The first prototypes were released in June 2008. The engineers' goal was to provide a platform that gave users access to desktop-like performance without the bulk or expense. The team also was trying to find a way to make it easy for a hobbyist to pick up the board and experiment without requiring a lot of embedded experience.
I can say that in my time working with the Beagle Board, they were able to achieve both goals. It isn't the fastest computer I have ever used, but it is very usable. It is so tiny, I occasionally would misplace it on my work bench. On the embedded side, I had some bumps choosing the right components, but once I got a working system, it was very straightforward.
A great place to get started is at elinux.org/BeagleBoardBeginners. The two big things to make sure of when you get into playing with the Beagle Board are compatibility and connectivity.
I used the Beagle Board serial cable to monitor what was going on. In several cases, I had incompatibilities (it took some tweaking to get the Beagle to show up properly on my living-room TV). I also grabbed a Wi-Fi dongle from Linksys, figuring that it would just work. In this case, it was too new. I went back and got the Belkin G F5D7050 that everyone else seems to be using, and I was able to get on the wireless network.
The Beagle Board beginners page actually links to a shopping list, showing you what you need and which versions to buy. I did not find that information until much later, so I am trying to help you avoid one of my mistakes.
The Beagle Board bootloader needs to be configured in order to run Linux. The good news is that once you do this setup, you don't have to do it again. You actually can do this step before you do anything else, and it's a good way to make sure you have everything ready for communication with your Beagle Board.
First, install minicom on your Linux host. You will need to change some settings:
sudo minicom -s
Inside minicom, you need to enter the “Serial port setup”. Make sure you set the correct device to which to talk. In my case, I have the serial cable connected to a serial-to-USB dongle. That means my serial device is /dev/ttyUSB0. Make sure the Bps/Par/Bits is set to 115200 8N1. Turn off all hardware and software control. Once that is done, save it as the default.
Now, connect the serial cable to your Beagle Board, start minicom, and power on the Beagle Board. You should see a message about the OMAP3530 being ready. It also will show you a countdown until autoboot. You need to press a key to stop the boot process, so you can change some settings.
Once you are at the OMAP3 beagleboard.org prompt, type the following:
setenv bootcmd 'mmcinit; fatload mmc 0:1 0x80300000 ↪uImage; bootm 0x80300000' setenv bootargs 'console=ttyS2,115200n8 console=tty0 ↪root=/dev/mmcblk0p2 rootwait rootfstype=ext3 ro omapfb.mode=dvi:1024x768MR-24@60' saveenv printenv
This configures your Beagle Board to look for the kernel image you are going to create. Now you need to get an SD card and prepare it to work for the Beagle Board.