MFRC522 is applied to the highly integrated read and write 13.56MHz contactless communication card chip, NXP launched by the company for the “table” application of a low-voltage, low-cost, small size of non-contact card chip, smart meters and portable handheld devices developed better choice. The MFRC522 use of advanced modulation and demodulation concept completely integrated in all types of 13.56MHz passive contactless communication methods and protocols. In addition, support rapid CRYPTO1 encryption algorithm, terminology validation MIFARE products. MFRC522 support MIFARE series of high-speed non-contact communication, two-way data transmission rate up to 424kbit/s.


  1. Operating Current :13-26mA/DC 3.3V
  2. Idle Current :10-13mA/DC 3.3V
  3. Sleep Current: <80uA
  4. Peak Current: <30mA
  5. Operating Frequency: 13.56MHz
  6. Supported card types: mifare1 S50、mifare1 S70、mifare UltraLight、mifare Pro、mifare Desfire
  7. Environmental Operating Temperature: -20-80 degrees Celsius
  8. Environmental Storage Temperature: -40-85 degrees Celsius
  9. Relative humidity: relative humidity 5% -95%
  10. Data transfer rate: maximum 10Mbit/s
  11. Size: RFID-RC522 Module:3.9 x 6 cm
  12. The Standard S50 Blank Card :8.5 x 5.4 cm
  13. Diameter of S50 special-shaped card: 3.1(max)



The PCA9685 is an I2C-bus controlled 16-channel LED controller optimized for LCD Red/Green/Blue/Amber (RGBA) color backlighting applications. Each LED output has its own 12-bit resolution (4096 steps) fixed frequency individual PWM controller that operates at a programmable frequency from a typical of 40 Hz to 1000 Hz with a duty cycle that is adjustable from 0 % to 100 % to allow the LED to be set to a specific brightness value. All outputs are set to the same PWM frequency.

PCA9685 also has a built-in oscillator for the PWM control. However, the frequency used for PWM control in the PCA9685 is adjustable from about 40 Hz to 1000 Hz as compared to the typical 97.6 kHz frequency of the PCA9635. This allows the use of PCA9685 with external power supply controllers. All bits are set at the same frequency. The PCA9685 has 4096 steps (12-bit PWM)