An Arduino/PlatformIO library for the CLRC633 RFID-reader module
Copyright (c) 2023 tueddy (Dirk Carstensen)
- can be connected via SPI or I2C (2 GPIOs less)
- read ISO-14443 UID's
- read ISO-18693 UID's
- support for ICode-SLIX password protected tags (privacy mode) / custom tags
- LPCD - low power card detection
- Auto calibration for LPCD-mode. Avoid false wakeups like in PN5180-library: https://github.com/tueddy/PN5180-Library
Some header declarations and functions taken and extended from https://github.com/kenny5660/CLRC663.git
You can get this reader module on AliExpress or eBay:
The CLRC663 reader can be connected with SPI or I2C, modules are delivered in SPI mode. Connect these pins:
- GND/3.3V for power
- Connect SD (shutdown/Power-down) to GND
- IRQ_PIN is optional and can be IRQ_PIN=-1. The IRQ-Pin is for wakeup the ESP-32 from deep-sleep.
For SPI use MOSI, MISO, SCLK
Create a SPI instance with
CLRC663 reader(&SPI, CHIP_SELECT, IRQ_PIN);For I2C use SDA and SCL Create a I2C instance with
CLRC663 reader(0x2A, IRQ_PIN);Module is delivered in SPI mode by default. If you need to change your CLRC663 module to work with I2C, you can easily do so by using a hot air gun/rework station and changing two resistors R2 -> R1, and R4 -> R8:

I2C address is 0x2A. More default information changing to I2C and change I2C address to 0x28 here: https://blog.edhayes.us/2022/02/23/clrc663-module-spi-i2c/
For Arduino you can download the library as zip and call include Library -> zip library. Or you can git clone this project into the Arduino libraries folder e.g. with
cd ~/Documents/Arduino/libraries
git clone tueddy/CLRC663-Library.git
For PlatformIO include the library in platform.ini:
lib_deps =
https://github.com/tueddy/CLRC663-Library.git

