Raspberry Pi

After many months I got my Raspberry Pi in the mail.  Even though I've seen many pictures of it, it still looks much smaller than I thought.  If you don't know what a Raspberry Pi is, its a tiny computer about the size of a deck of cards.   Its just the board through, no fancy case.  It also has a bunch of extra pins on it so you can do some I/O, like reading switches and setting LEDs.  You also need to supply your own power supply and memory card.

I used my USB phone charger cable to power it.  I've read some phone cables don't work, but this one seems to work, so far.  I copied the Debian image from the Raspberry Pi website on to the memory card and booted up with no problem.  Next I looked for something interesting to try out.  I found this post about streaming Pandora music.  I followed it and was able to connect to Pandora, but the music would stop after a second or two.  Turns out there was a bug in the ALSA (sound) drivers.   If you background the task (Ctrl-Z) and then foreground it again (fg), it would play for a few more seconds.  I next tried the beta Debian image on the Raspberry Pi website, since it was newer.  It still had the problem.  After a a little google search I found this.  Apparently they just fixed the driver a few days ago.  To update the firmware I used Hexxah's raspi-update tool.  Just had to run it and reboot when it finishes.  I tried pianobar and it work that time.

Next was the GPIO pins.  They are perfectly spaced out for an old ribbon cable.  I first tried and IDE cable but realized it was one of the UMA 66 with extra conductors in it.  Rather than chance anything funny with that cable I found an old floppy drive cable.  It fits over the pins with the last 4 rows sticking out.  I then wired an old bread board I had to an LED and switch using this diagram.  I next used the RPi.GPIO library and wrote a script to toggle the LED on the switch.  The LED was a little dim the for the first test, so I swapped the resistor for a smaller one and its much brighter now.

Something of note, I had used the wrong pin diagram incorrectly wired the wrong GPIO to the switch, and the Pi instantly turned off.  Thought I had blown something, but after only minute of being off it came back up fine.  Another thing to know is the GPIO to turn a LED on is TRUE and FALSE to turn it off, while reading a switch is TRUE when its open and FALSE when its closed.

If any cares I can post pictures.