Before I get too far down the Raspberry Pi series I have started, I wanted to take a few minutes and talk about one of the first things that you should get when you get your Raspberry Pi. For those who have worked with a variety of network equipment over the years, you know that the serial console cable is one of the most important and most used tools in your bag of tricks. In my brief experience with the RPi, it has proven to be a very reliable unit but I always like having a way to access the system that will always work, no matter what. You can get this cable from the good folks at Adafruit.
The picture you see is that very tool. It plugs directly into the two rows of pins that you see on the lower left hand corner of the board (when looking at the board where the SD card slot is on your right). There are 4 wires that will plug into the lower row of pins on that board. The red wire plugs into the right most pin on the board, the black wire plugs in two pins over to the left, the white wire plugs into the next pin and the grey wire plugs into the pin to the left of the white wire. When plugged in correctly, the wires should look like grey,white,black,skip_pin,black with the black wire being on the right most pin on the bottom row of pins.
One thing that is important to remember is to not plug the red wire (hence referred to as the power wire), if you are using a power supply plugged into the mini USB port that is located to the right of the SD card slot. You run the risk of damaging your new RPi. For bringing up just the RPi with nothing else attached to it, using the USB power will be fine. My thoughts are that if you are bringing up much more than than, I would feel more comfortable with using a dedicated power supply and not taxing the 5v line coming from your computers USB port.
As we progress down the different projects I have planned for my RPi, I will mostly use the Serial cable so that I can have complete out-of-band access, just in case I make a configuration change and don’t want to reboot the RPi to recover from it. One of my plans is to add a secondary ethernet port so that I can connect directly into the RPi over ethernet when I am testing functionality such as a portable hotspot, firewall, etc.
To see more of my posts about the Raspberry Pi, please go to http://www.ronnutter.com/category/raspberry-pi/