sensor
8 pages across tutorials, modules, pinouts and guides.

4-Direction Tilt Sensor
One metal roller in a square switch with four corner contacts, on a TinkerBlock board: tip an edge down and the roller joins that side's two lines. Your board finds which pair by holding one line LOW and reading who follows. Four answers and none, no angle, and four red LEDs that light when a line is held LOW.

Ambient Light Sensor
A phototransistor and a 4.7 kΩ resistor on a TinkerBlock board: light makes a current, the resistor turns it into a voltage, and SIGNAL rises with the light. A lit room reads low on the scale, bright light flattens just under VCC, and it sees near infrared best.

Analog Microphone
An electret capsule and a one-transistor amplifier on a TinkerBlock board. SIGNAL rests at a level set by the transistor's gain and swings above and below it with sound, in a band of roughly 75 Hz to 1 kHz. Read the peak-to-peak over 50 ms: it hears claps, knocks and loud voices, and it is not a recording microphone.

Collision Sensor
A lever microswitch with its 10 kΩ pull-down and a red hit light already fitted: SIGNAL reads HIGH while the lever is pushed in. The bumper for a TinkerBlock robot, and the sense that never reports a wall that is not there.

Hall Effect Sensor
An omnipolar Hall switch on a TinkerBlock board: bring either pole of a magnet near and SIGNAL goes LOW and a red light comes on. No contact to wear out, it works through plastic, and it looks at the field every 22 ms, so it is made for doors, lids and slow wheels.

IR Receiver
A Vishay TSOP18138 38 kHz infrared receiver on a TinkerBlock board: SIGNAL idles HIGH and goes LOW while a remote sends, and the IRremote library turns those lows into an address and a command.

Knock Sensor
A spring vibration switch with its 10 kΩ pull-down, a 100 nF capacitor and a red flash light already fitted: SIGNAL goes HIGH for a moment each time a knock swings the spring onto its rod. A tap on a table as a button, a door that was knocked, a box that was dropped.

NTC Thermistor
A 10 kΩ NTC thermistor in a divider with a fixed 10 kΩ: SIGNAL is half of VCC at 25 °C and falls as it warms. Read it on any analog pin and turn it into degrees with two lines of arithmetic.