Voltage Divider any circuit that produces an output that is a fraction of its input.

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1 Sensor workshop Voltage Divider any circuit that produces an output that is a fraction of its input. Z = impedance, which is the AC analogue of resistance Examples of Voltage Dividers: two resistors in series (see above) or a potentiometer. The basic Voltage Divider model, above, will be the configuration for most sensors into the arduino (where Vout representes Analog In 0, for example) Potentiometer There are two ears and a nose. The nose is the output, the ears are inputs. The only thing that matters regarding which ear you use is which direction you turn the knob to increase/decrease resistance. So, for pot, to interface with arduino: Nose to any input (example: A0) Ear 1 to ground Ear 2 to 5V or 3.3V See AnalogIn in examples (in arduino documentation) LDR/Photoresistor LDR stands for light dependent resistor...in other words, resistance decreases with increasing light intensity. This phenomenon is known as photoconductivity. Schematic symbol

2 Circuit for input to arduino (will cover most configurations) -notice that this is exactly the same as the Voltage Divider schematic above Basic configuration for LED use: In this configuration, the darker it is, the brighter the LED will shine.

3 FSR (force sensitive resistor) As the resistance of the FSR decreases, the total resistance of the FSR and the pulldown resistor decreases. As the total resistance decreases, the current flow increases, which causes the Voltage across the fixed resistor to increase. Connect one end to Power (5V), and the other end to both a pull-down resistor (to ground) then to any Analog input. FSR plus LED configuration:

4 Accelerometer (ADXL335) VCC to 3.3V X to A0 Y to A1 Z to A2 measures acceleration caused by motion -when the accelerometer is still, the only acceleration it sense is due to gravity pulling down on it. If you imagine a box with springs, an accelerometer measures how hard gravity is stretching those springs. Accelerometers do not provide any sense of direction. In order to get motion and orientation readings, one would need to pair an accelerometer with something like a gyroscope. Ultrasonic Range Finder (MB1010) (for analog mode) +5 to +5 Rx may be left open (i.e. not connected) for most situations An to Analog in Pw not used in Analog mode Bw open for most situations (for PW mode) +5 to +5 Rx may be left open (i.e. not connected) for most situations An not used in PW mode Pw to Digital in Bw open for most situations The MB1010 obtains readings by outputting a ping (some short sound, think of the sound effects used to demonstrate the use of sonar in movies as an analogy) and tracking the amount of time it takes to detect the reflection of that ping. In other words, this is a sonar device. There are two measurement possibilities: analog and PW (pulse width), or digital. The PW mode seems to provide more accuracy.

5 Infrared Proximity Sensor (Sharp GPY0A02YK0F) Similar in operation to the MB1010, however it outputs a beam of infrared light and tracks the amount of time it takes to detect the reflection of that initial beam. This particular sensor has a very long range (can sense objects up to five feet away). Note: this sensor's pin outs appear to be only matched with this connector: (using the above connector's colored wires to distinguish each pin) yellow to Analog in red to the 5V black to GRD Temperature Sensor (LM335) Basically, as the temperature increases, the amount of voltage across a diode increases at some known rate. By amplifying the voltage change, one can easily generate an analog signal directly propotional to the temperature measured. In order to correctly use this sensor, you will need a potentiometer to calibrate it. After calibration, and with the use of this LM335 arduino library (which will do all the conversions for you), you should easily get usable temperature readings.