At first glance, some rotary encoders look a lot like the potentiometers used as knobs on radios and other control boards. They both can serve a similar purpose in providing rotational information to a circuit. However, these components are fundamentally very different:
Passive RFID tags are basically just little antennas with an extremely low power integrated circuit. When the IC is activated by power induced by the antenna, it generates a signal to transmit a small amount of data, such as an ID number.
This RC522 RFID module can read RFID tags and write to RFID tags that support writing. The RFID tag has a 4-byte (or 32-bit) UID, which means there are about 4.3 billion unique possibilities. Although that sounds like a lot, there are some situations where it's not considered enough to prevent collisions or brute-force guessing.
The MAX7219 LED matrix module used in this example has 64 distinct LEDs that can be individually turned on or off in the Arduino code.
It uses SPI to control 64 individual LEDs while consuming just three GPIO pins on the microcontroller, plus the VCC and GND pins for powering the LED module. The module also has output pins that can be chained together with up to eight (or more) modules.
We will use a library called LEDMatrixDriver, which purports to be faster than another library called LedControl.
This is a brief introduction to the Arduino hardware and software platforms. When someone mentions "Arduino" in conversation, the word can mean a number of things:
Here we will explore encoding data with analog signals or with digital signals that serve a purpose similar to analog signals.
Each Arduino board has a row of pins capable of reading analog input. By "analog" we mean that the input data is determined by the voltage applied to the pin. Although in theory there are infinitely many levels between any two voltages, the actual number of distinct values is limited by noise and the type of hardware reading the voltages.
The analog joystick module is basically two potentiometers arranged at right angles to each other. As you manipulate the joystick, the potentiometers change in different ratios, which your code can use to determine the joystick's angle and distance from center. Some joystick modules also act like a button when pressed.