Sensors & Actuators
Microphone
This electret microphone is a sensor that turns soundwaves into a voltage signal. It can be used with the example schematic. You may need to amplify the signal using an opamp depending on the application.
Example Schematic Datasheet
100K NTC Thermistor
This sensor is a variable resistor that varies its resistance with the temperature of the bead. At room temperature (25 degrees Celsius) the resistance is 100 kΩ. The resistance goes up as the temperature drops and vice versa. The exact T/R curve can be calculated or read from a table in the datasheet. The curve can be calculated with parameters found in the datasheet and the formula below.
To get a voltage signal proportional to temperature, the NTC may be used in a voltage divider.
SG90 RC Servo
This servo motor is used in applications where actuation to a certain angle is needed. It does not work like a normal motor as it cannot fully rotate around its axis, but has a certain range of motion.
The servo has three wires, orange, red and brown. These are expecting a control input, power and ground respectively. The control input is a PWM signal, from which the desired angle of the servo arm is set. Below you will find an ESP8266 library that may help you control the servo motor.
DC Motor
This DC motor is one of the simplest to drive motors. It accepts a DC voltage at its terminals, the polarity of which determines the direction in which the motor spins. When used in a system, a flyback diode is required for back-EMF protection. To control the motor with a digital signal, the schematic below can be used.
Example Schematic Datasheet
9V Battery Clip
Used to connect 9V batteries to your projects. The red wire connects to the positive terminal of the battery, the black wire to the negative terminal.
Pushbutton
This momentary push button will connect the terminals on the two sides when pressed down. The button can be used in a breadboard or prototype board. The pinout button below shows the pinout of the button.
Pinout
Piezo Buzzer
This buzzer has a piezo element inside. This crystal element expands and contracts by applying a voltage to is. Supplying a square wave to the buzzer will generate a sound.
Current amplification may be nessecary to drive the buzzer. The circuit found below may be used to drive the buzzer.
LDR
This light dependent resistor can be used to make a system light sensitive. The resistance of the LDR changes with illumination, where the resistance drops when illuminated and vice versa. The datasheet provides several suggested uses depending on the application.
Datasheet
Photodiode
The photodiode contains a P-N junction that generates an electrical current when photons hit it. In layman's terms; it generates electricity with light, just like a solar panel does. Typical applications for a photo diode are for example CD players, smoke detectors and IR receivers.
Datasheet