Which motion sensor would I use in the following situations?
To detect when someone is walking in a room. Would the applicable sensor to use be a PIR Motion Sensor?
To detect when my physical mailbox is opening up. I'm not sure what sensor I would use for this?
Also if I wanted to email the results to myself, I would use a WiFi shield?
I didn't know there was over 100 components for this. Jeez. http://playground.arduino.cc/Main/InterfacingWithHardware#motion_gyro
Any help and I'd appreciate it. I'll start with the door project first because it's more novice.