The (name?)...Well, let's just call it Bob. Bob has five sensors
- Ultrasonic Rangefinder (aka "sonar")
- 2 Sharp GP2D12 IR Sensors
- 1 Standard IR Assembly (more on this later)
- 1 CdS (Cadmium Sulphide) Photocell
The ultrasonic rangefinder helps Bob see obstacles that are right in front of him; they also tell him what distance
the object is from him. This can be obtained from many sources. You can find them from (Parallax
; they call it the "Ping)))"), Acroname
, HVW Technologies
, and so many more sites. No matter where you go to find them, they all cost about the same (~ $30). The two IR sensors made by Sharp are very easy to use when used for simple object detection as in this case. You can get them at may online stores, such as the ones listed above. They help Bob see obstacles that the ultrasonic rangefinder can't; obstacles that are coming too close to the sides of the chasis. They cost about $12 to $15 depending on where you get them. The "IR assembly" I made myself; see step 2 for assembly. The CdS Photocell (or light-variable resistor, whatever your preference) is for detecting changes in ambient lighting. Bob uses them to know when he's in a dark or light room.
If anyone who has prior experience with any of the Sharp IR rangers, FYI, they are not being used for actual distance measurement in this robot. I do not have an ADC (Analog-to-Digital Converter), neither do I know how to use them that way. They are simply providing a HIGH or LOW signal to the BS2 microcontroller.
The datasheets for the Sharp IR's as well as the Ping))) sensor can be found on the net, but if you're lazy like me, you can scroll down a little further an there they are!