diff --git a/20_RFID_rc522/CMakeLists.txt b/20_RFID_rc522/CMakeLists.txt
new file mode 100644
index 0000000..b787426
--- /dev/null
+++ b/20_RFID_rc522/CMakeLists.txt
@@ -0,0 +1,10 @@
+# The following lines of boilerplate have to be in your project's CMakeLists
+# in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.5)
+
+set(EXTRA_COMPONENTS_DIRS "./components")
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+
+project(lcd)
+
+
diff --git a/20_RFID_rc522/Makefile b/20_RFID_rc522/Makefile
new file mode 100644
index 0000000..0b65549
--- /dev/null
+++ b/20_RFID_rc522/Makefile
@@ -0,0 +1,9 @@
+#
+# This is a project Makefile. It is assumed the directory this Makefile resides in is a
+# project subdirectory.
+#
+
+PROJECT_NAME := lcd
+
+include $(IDF_PATH)/make/project.mk
+
diff --git a/20_RFID_rc522/README_cn.md b/20_RFID_rc522/README_cn.md
new file mode 100644
index 0000000..13e8a5d
--- /dev/null
+++ b/20_RFID_rc522/README_cn.md
@@ -0,0 +1,13 @@
+# RFID-RC522 ESP32示范
+
+此工程展示了 ESP32 驱动 RFID-RC522 的驱动示范！
+
+IDF工程：`origin/release/v4.2`
+
+commit：`cd4fa46f5372a552a67452313d246d4d09d2b39f`
+
+* ESP32 -- RC522连接
+
+RC522|MISO|MOSI|SCK|SDA
+ ---|---| ---|---| ---
+ ESP32 |GPIO25|GPIO23|GPIO19|GPIO22
diff --git a/20_RFID_rc522/components/RC522/CMakeLists.txt b/20_RFID_rc522/components/RC522/CMakeLists.txt
new file mode 100644
index 0000000..d074d4c
--- /dev/null
+++ b/20_RFID_rc522/components/RC522/CMakeLists.txt
@@ -0,0 +1,4 @@
+set(COMPONENT_SRCS "rc522.c")
+set(COMPONENT_ADD_INCLUDEDIRS "include")
+
+register_component()
diff --git a/20_RFID_rc522/components/RC522/component.mk b/20_RFID_rc522/components/RC522/component.mk
new file mode 100644
index 0000000..0b9d758
--- /dev/null
+++ b/20_RFID_rc522/components/RC522/component.mk
@@ -0,0 +1,5 @@
+#
+# "main" pseudo-component makefile.
+#
+# (Uses default behaviour of compiling all source files in directory, adding 'include' to include path.)
+
diff --git a/20_RFID_rc522/components/RC522/include/rc522.h b/20_RFID_rc522/components/RC522/include/rc522.h
new file mode 100644
index 0000000..1494322
--- /dev/null
+++ b/20_RFID_rc522/components/RC522/include/rc522.h
@@ -0,0 +1,42 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "driver/spi_master.h"
+#include "driver/spi_common_internal.h"
+
+typedef void(*rc522_tag_callback_t)(uint8_t*);
+
+typedef struct {
+    int miso_io;
+    int mosi_io;
+    int sck_io;
+    int sda_io;
+    rc522_tag_callback_t callback;
+} rc522_start_args_t;
+
+esp_err_t rc522_spi_init(int miso_io, int mosi_io, int sck_io, int sda_io);
+esp_err_t rc522_write_n(uint8_t addr, uint8_t n, uint8_t *data);
+esp_err_t rc522_write(uint8_t addr , uint8_t val);
+uint8_t* rc522_read_n(uint8_t addr, uint8_t n) ;
+uint8_t rc522_read(uint8_t addr);
+#define rc522_fw_version() rc522_read(0x37)
+esp_err_t rc522_init();
+
+esp_err_t rc522_set_bitmask(uint8_t addr, uint8_t mask);
+esp_err_t rc522_clear_bitmask(uint8_t addr, uint8_t mask);
+esp_err_t rc522_antenna_on();
+uint8_t* rc522_calculate_crc(uint8_t *data, uint8_t n);
+uint8_t* rc522_card_write(uint8_t cmd, uint8_t *data, uint8_t n, uint8_t* res_n);
+uint8_t* rc522_request(uint8_t* res_n);
+uint8_t* rc522_anticoll();
+uint8_t* rc522_get_tag();
+esp_err_t rc522_start(rc522_start_args_t start_args);
+esp_err_t rc522_resume();
+esp_err_t rc522_pause();
+
+#ifdef __cplusplus
+}
+#endif
\ No newline at end of file
diff --git a/20_RFID_rc522/components/RC522/rc522.c b/20_RFID_rc522/components/RC522/rc522.c
new file mode 100644
index 0000000..0be3c1e
--- /dev/null
+++ b/20_RFID_rc522/components/RC522/rc522.c
@@ -0,0 +1,392 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "esp_system.h"
+#include "driver/spi_master.h"
+#include "soc/gpio_struct.h"
+#include "driver/gpio.h"
+#include "esp_timer.h"
+#include "rc522.h"
+
+spi_device_handle_t rc522_spi;
+static esp_timer_handle_t rc522_timer;
+static bool rc522_timer_running = false;
+
+esp_err_t rc522_spi_init(int miso_io, int mosi_io, int sck_io, int sda_io)
+{
+    spi_bus_config_t buscfg = {
+        .miso_io_num = miso_io,
+        .mosi_io_num = mosi_io,
+        .sclk_io_num = sck_io,
+        .quadwp_io_num = -1,
+        .quadhd_io_num = -1};
+
+    spi_device_interface_config_t devcfg = {
+        .clock_speed_hz = 5000000,
+        .mode = 0,
+        .spics_io_num = sda_io,
+        .queue_size = 7,
+        .flags = SPI_DEVICE_HALFDUPLEX};
+
+    esp_err_t ret;
+#ifdef CONFIG_IDF_TARGET_ESP32
+    ret = spi_bus_initialize(VSPI_HOST, &buscfg, 0);
+#elif CONFIG_IDF_TARGET_ESP32S2
+    ret = spi_bus_initialize(HSPI_HOST, &buscfg, 0);
+#endif
+    if (ret != ESP_OK)
+    {
+        return ret;
+    }
+#ifdef CONFIG_IDF_TARGET_ESP32
+    ret = spi_bus_add_device(VSPI_HOST, &devcfg, &rc522_spi);
+#elif CONFIG_IDF_TARGET_ESP32S2
+    ret = spi_bus_add_device(HSPI_HOST, &devcfg, &rc522_spi);
+#endif
+    return ret;
+}
+
+esp_err_t rc522_write_n(uint8_t addr, uint8_t n, uint8_t *data)
+{
+    uint8_t *buffer = (uint8_t *)malloc(n + 1);
+    buffer[0] = (addr << 1) & 0x7E;
+
+    for (uint8_t i = 1; i <= n; i++)
+    {
+        buffer[i] = data[i - 1];
+    }
+
+    spi_transaction_t t;
+    memset(&t, 0, sizeof(t));
+
+    t.length = 8 * (n + 1);
+    t.tx_buffer = buffer;
+
+    esp_err_t ret = spi_device_transmit(rc522_spi, &t);
+
+    free(buffer);
+
+    return ret;
+}
+
+esp_err_t rc522_write(uint8_t addr, uint8_t val)
+{
+    return rc522_write_n(addr, 1, &val);
+}
+
+/* Returns pointer to dynamically allocated array of N places. */
+uint8_t *rc522_read_n(uint8_t addr, uint8_t n)
+{
+    if (n <= 0)
+    {
+        return NULL;
+    }
+
+    spi_transaction_t t;
+    memset(&t, 0, sizeof(t));
+
+    uint8_t *buffer = (uint8_t *)malloc(n);
+
+    t.flags = SPI_TRANS_USE_TXDATA;
+    t.length = 8;
+    t.tx_data[0] = ((addr << 1) & 0x7E) | 0x80;
+    t.rxlength = 8 * n;
+    t.rx_buffer = buffer;
+
+    esp_err_t ret = spi_device_transmit(rc522_spi, &t);
+    assert(ret == ESP_OK);
+
+    return buffer;
+}
+
+uint8_t rc522_read(uint8_t addr)
+{
+    uint8_t *buffer = rc522_read_n(addr, 1);
+    uint8_t res = buffer[0];
+    free(buffer);
+
+    return res;
+}
+
+esp_err_t rc522_init()
+{
+    // ---------- RW test ------------
+    rc522_write(0x24, 0x25);
+    assert(rc522_read(0x24) == 0x25);
+
+    rc522_write(0x24, 0x26);
+    assert(rc522_read(0x24) == 0x26);
+    // ------- End of RW test --------
+
+    rc522_write(0x01, 0x0F);
+    rc522_write(0x2A, 0x8D);
+    rc522_write(0x2B, 0x3E);
+    rc522_write(0x2D, 0x1E);
+    rc522_write(0x2C, 0x00);
+    rc522_write(0x15, 0x40);
+    rc522_write(0x11, 0x3D);
+
+    rc522_antenna_on();
+
+    printf("RC522 Firmware 0x%x\n", rc522_fw_version());
+
+    return ESP_OK;
+}
+
+esp_err_t rc522_set_bitmask(uint8_t addr, uint8_t mask)
+{
+    return rc522_write(addr, rc522_read(addr) | mask);
+}
+
+esp_err_t rc522_clear_bitmask(uint8_t addr, uint8_t mask)
+{
+    return rc522_write(addr, rc522_read(addr) & ~mask);
+}
+
+esp_err_t rc522_antenna_on()
+{
+    esp_err_t ret;
+
+    if (~(rc522_read(0x14) & 0x03))
+    {
+        ret = rc522_set_bitmask(0x14, 0x03);
+
+        if (ret != ESP_OK)
+        {
+            return ret;
+        }
+    }
+
+    return rc522_write(0x26, 0x60); // 43dB gain
+}
+
+/* Returns pointer to dynamically allocated array of two element */
+uint8_t *rc522_calculate_crc(uint8_t *data, uint8_t n)
+{
+    rc522_clear_bitmask(0x05, 0x04);
+    rc522_set_bitmask(0x0A, 0x80);
+
+    rc522_write_n(0x09, n, data);
+
+    rc522_write(0x01, 0x03);
+
+    uint8_t i = 255;
+    uint8_t nn = 0;
+
+    for (;;)
+    {
+        nn = rc522_read(0x05);
+        i--;
+
+        if (!(i != 0 && !(nn & 0x04)))
+        {
+            break;
+        }
+    }
+
+    uint8_t *res = (uint8_t *)malloc(2);
+
+    res[0] = rc522_read(0x22);
+    res[1] = rc522_read(0x21);
+
+    return res;
+}
+
+uint8_t *rc522_card_write(uint8_t cmd, uint8_t *data, uint8_t n, uint8_t *res_n)
+{
+    uint8_t *result = NULL;
+    uint8_t irq = 0x00;
+    uint8_t irq_wait = 0x00;
+    uint8_t last_bits = 0;
+    uint8_t nn = 0;
+
+    if (cmd == 0x0E)
+    {
+        irq = 0x12;
+        irq_wait = 0x10;
+    }
+    else if (cmd == 0x0C)
+    {
+        irq = 0x77;
+        irq_wait = 0x30;
+    }
+
+    rc522_write(0x02, irq | 0x80);
+    rc522_clear_bitmask(0x04, 0x80);
+    rc522_set_bitmask(0x0A, 0x80);
+    rc522_write(0x01, 0x00);
+
+    rc522_write_n(0x09, n, data);
+
+    rc522_write(0x01, cmd);
+
+    if (cmd == 0x0C)
+    {
+        rc522_set_bitmask(0x0D, 0x80);
+    }
+
+    uint16_t i = 1000;
+
+    for (;;)
+    {
+        nn = rc522_read(0x04);
+        i--;
+
+        if (!(i != 0 && (((nn & 0x01) == 0) && ((nn & irq_wait) == 0))))
+        {
+            break;
+        }
+    }
+
+    rc522_clear_bitmask(0x0D, 0x80);
+
+    if (i != 0)
+    {
+        if ((rc522_read(0x06) & 0x1B) == 0x00)
+        {
+            if (cmd == 0x0C)
+            {
+                nn = rc522_read(0x0A);
+                last_bits = rc522_read(0x0C) & 0x07;
+
+                if (last_bits != 0)
+                {
+                    *res_n = (nn - 1) + last_bits;
+                }
+                else
+                {
+                    *res_n = nn;
+                }
+
+                result = (uint8_t *)malloc(*res_n);
+
+                for (i = 0; i < *res_n; i++)
+                {
+                    result[i] = rc522_read(0x09);
+                }
+            }
+        }
+    }
+
+    return result;
+}
+
+uint8_t *rc522_request(uint8_t *res_n)
+{
+    uint8_t *result = NULL;
+    rc522_write(0x0D, 0x07);
+
+    uint8_t req_mode = 0x26;
+    result = rc522_card_write(0x0C, &req_mode, 1, res_n);
+
+    if (*res_n * 8 != 0x10)
+    {
+        free(result);
+        return NULL;
+    }
+
+    return result;
+}
+
+uint8_t *rc522_anticoll()
+{
+    uint8_t *result = NULL;
+    uint8_t res_n;
+    uint8_t serial_number[] = {0x93, 0x20};
+
+    rc522_write(0x0D, 0x00);
+
+    result = rc522_card_write(0x0C, serial_number, 2, &res_n);
+
+    if (result != NULL && res_n != 5)
+    {
+        free(result);
+        return NULL;
+    }
+
+    return result;
+}
+
+uint8_t *rc522_get_tag()
+{
+    uint8_t *result = NULL;
+    uint8_t *res_data = NULL;
+    uint8_t res_data_n;
+
+    res_data = rc522_request(&res_data_n);
+
+    if (res_data != NULL)
+    {
+        free(res_data);
+
+        result = rc522_anticoll(&res_data_n);
+
+        if (result != NULL)
+        {
+            uint8_t buf[] = {0x50, 0x00, 0x00, 0x00};
+            uint8_t *crc = rc522_calculate_crc(buf, 2);
+
+            buf[2] = crc[0];
+            buf[3] = crc[1];
+
+            free(crc);
+
+            res_data = rc522_card_write(0x0C, buf, 4, &res_data_n);
+            free(res_data);
+
+            rc522_clear_bitmask(0x08, 0x08);
+
+            return result;
+        }
+    }
+
+    return NULL;
+}
+
+static void rc522_timer_callback(void *arg)
+{
+    uint8_t *serial_no = rc522_get_tag();
+    
+    if (serial_no != NULL)
+    {
+        rc522_tag_callback_t cb = (rc522_tag_callback_t)arg;
+        cb(serial_no);
+        free(serial_no);
+    }
+}
+
+esp_err_t rc522_start(rc522_start_args_t start_args)
+{
+    assert(rc522_spi_init(
+               start_args.miso_io,
+               start_args.mosi_io,
+               start_args.sck_io,
+               start_args.sda_io) == ESP_OK);
+
+    rc522_init();
+
+    const esp_timer_create_args_t timer_args = {
+        .callback = &rc522_timer_callback,
+        .arg = (void *)start_args.callback};
+
+    esp_err_t ret = esp_timer_create(&timer_args, &rc522_timer);
+
+    if (ret != ESP_OK)
+    {
+        return ret;
+    }
+
+    return rc522_resume();
+}
+
+esp_err_t rc522_resume()
+{
+    return rc522_timer_running ? ESP_OK : esp_timer_start_periodic(rc522_timer, 125000);
+}
+
+esp_err_t rc522_pause()
+{
+    return !rc522_timer_running ? ESP_OK : esp_timer_stop(rc522_timer);
+}
\ No newline at end of file
diff --git a/20_RFID_rc522/main/CMakeLists.txt b/20_RFID_rc522/main/CMakeLists.txt
new file mode 100644
index 0000000..a757336
--- /dev/null
+++ b/20_RFID_rc522/main/CMakeLists.txt
@@ -0,0 +1 @@
+idf_component_register(SRCS "main.c")
\ No newline at end of file
diff --git a/20_RFID_rc522/main/component.mk b/20_RFID_rc522/main/component.mk
new file mode 100644
index 0000000..e69de29
diff --git a/20_RFID_rc522/main/main.c b/20_RFID_rc522/main/main.c
new file mode 100644
index 0000000..5c84280
--- /dev/null
+++ b/20_RFID_rc522/main/main.c
@@ -0,0 +1,45 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+
+#include "driver/spi_master.h"
+#include "driver/gpio.h"
+#include "rc522.h"
+#include "driver/gpio.h"
+
+static const char *TAG = "main";
+
+void tag_handler(uint8_t *serial_no)
+{
+    for (int i = 0; i < 5; i++)
+    {
+        printf("%#x ", serial_no[i]);
+    }
+
+    gpio_set_level(12, 0);
+    vTaskDelay(300 / portTICK_PERIOD_MS);
+    gpio_set_level(12, 1);
+    printf("\n");
+}
+
+void app_main(void)
+{
+
+    gpio_pad_select_gpio(12);
+    /* Set the GPIO as a push/pull output */
+    gpio_set_direction(12, GPIO_MODE_OUTPUT);
+
+    const rc522_start_args_t start_args = {
+        .miso_io = 25,
+        .mosi_io = 23,
+        .sck_io = 19,
+        .sda_io = 22,
+        .callback = &tag_handler
+    };
+
+    rc522_start(start_args);
+}