diff --git a/21_s2_sht20/CMakeLists.txt b/21_s2_sht20/CMakeLists.txt
new file mode 100644
index 0000000..2e184d8
--- /dev/null
+++ b/21_s2_sht20/CMakeLists.txt
@@ -0,0 +1,6 @@
+# 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)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(SHT20)
diff --git a/21_s2_sht20/Makefile b/21_s2_sht20/Makefile
new file mode 100644
index 0000000..76e9038
--- /dev/null
+++ b/21_s2_sht20/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 := sht20
+
+include $(IDF_PATH)/make/project.mk
+
diff --git a/21_s2_sht20/README.md b/21_s2_sht20/README.md
new file mode 100644
index 0000000..44cce18
--- /dev/null
+++ b/21_s2_sht20/README.md
@@ -0,0 +1,3 @@
+## ESP32-S2 驱动 SHT20 获取温湿度
+
+1. blog：https://blog.csdn.net/xh870189248/article/details/108824144
\ No newline at end of file
diff --git a/21_s2_sht20/components/SHT20/CMakeLists.txt b/21_s2_sht20/components/SHT20/CMakeLists.txt
new file mode 100644
index 0000000..7dcd86c
--- /dev/null
+++ b/21_s2_sht20/components/SHT20/CMakeLists.txt
@@ -0,0 +1,5 @@
+idf_component_register(
+    SRCS "library/sht20.c"
+    INCLUDE_DIRS "include"
+)
+
diff --git a/21_s2_sht20/components/SHT20/component.mk b/21_s2_sht20/components/SHT20/component.mk
new file mode 100644
index 0000000..b9a4260
--- /dev/null
+++ b/21_s2_sht20/components/SHT20/component.mk
@@ -0,0 +1,3 @@
+COMPONENT_ADD_INCLUDEDIRS := include
+
+COMPONENT_SRCDIRS := library
diff --git a/21_s2_sht20/components/SHT20/include/sht20.h b/21_s2_sht20/components/SHT20/include/sht20.h
new file mode 100644
index 0000000..3f1cf61
--- /dev/null
+++ b/21_s2_sht20/components/SHT20/include/sht20.h
@@ -0,0 +1,60 @@
+/*
+ * @Author: your name
+ * @Date: 2020-09-27 10:21:48
+ * @LastEditTime: 2020-09-27 10:42:19
+ * @LastEditors: Please set LastEditors
+ * @Description: In User Settings Edit
+ * @FilePath: \esp-idf\examples\me\sht20\components\SHT20\include\sht20.h
+ */
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define SHT20_I2C_NUM  (1)
+#define SHT20_SCL_NUM (GPIO_NUM_19)
+#define SHT20_SDA_NUM (GPIO_NUM_18)
+
+#define DEV_SHT20_SCL_NUM               SHT20_SCL_NUM               /*!< gpio number for I2C master clock */
+#define DEV_SHT20_SDA_NUM               SHT20_SDA_NUM               /*!< gpio number for I2C master data  */
+#define DEV_SHT20_I2C_NUM               SHT20_I2C_NUM               /*!< I2C port number for master dev */
+#define I2C_MASTER_FREQ_HZ              (100000)                    /*!< I2C master clock frequency */
+#define I2C_MASTER_TX_BUF_DISABLE 0                                 /*!< I2C master doesn't need buffer */
+#define I2C_MASTER_RX_BUF_DISABLE 0                                 /*!< I2C master doesn't need buffer */
+
+#define WRITE_BIT 0 /*!< I2C master write */
+#define READ_BIT 1   /*!< I2C master read */
+
+#define ACK_CHECK_EN 0x1           /*!< I2C master will check ack from slave*/
+#define ACK_CHECK_DIS 0x0          /*!< I2C master will not check ack from slave */
+#define ACK_VAL 0x0                /*!< I2C ack value */
+#define NACK_VAL 0x1               /*!< I2C nack value */
+
+#define ESP_SLAVE_ADDR 0x40
+#define HOLD_AT_START 0xe3    //触发温度测量
+#define HOLD_AH_START 0xe5    //触发湿度测量
+#define REST 0xfe             //软件复位
+
+
+/*
+ * 
+ */
+void init_sht20(void);
+
+
+/*
+ * 
+ */
+float get_sht20_Temperature(void);
+
+
+/*
+ * 
+ */
+float get_sht20_Humidity(void);
+
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/21_s2_sht20/components/SHT20/library/sht20.c b/21_s2_sht20/components/SHT20/library/sht20.c
new file mode 100644
index 0000000..2f84db1
--- /dev/null
+++ b/21_s2_sht20/components/SHT20/library/sht20.c
@@ -0,0 +1,147 @@
+#include <stdio.h>
+#include "esp_log.h"
+#include "driver/i2c.h"
+#include "sdkconfig.h"
+#include "string.h"
+
+#include "sht20.h"
+
+static const char *TAG = "sht20_drive.c";
+
+static esp_err_t i2c_master_read_slave(i2c_port_t i2c_num, uint8_t *data_rd, size_t size)
+{
+    if (size == 0)
+    {
+        return ESP_OK;
+    }
+
+    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
+    i2c_master_start(cmd);
+    i2c_master_write_byte(cmd, (ESP_SLAVE_ADDR << 1) | READ_BIT, ACK_CHECK_EN);
+
+    
+    if (size > 1)
+    {
+        i2c_master_read(cmd, data_rd, size - 1, ACK_VAL);
+    }
+
+    i2c_master_read_byte(cmd, data_rd + size - 1, NACK_VAL);
+    i2c_master_stop(cmd);
+    esp_err_t ret = i2c_master_cmd_begin(i2c_num, cmd, 1000 / portTICK_RATE_MS);
+    
+    i2c_cmd_link_delete(cmd);
+
+    return ret;
+}
+
+/**
+ * @brief Test code to write esp-i2c-slave
+ *        Master device write data to slave(both esp32),
+ *        the data will be stored in slave buffer.
+ *        We can read them out from slave buffer.
+ *
+ * ___________________________________________________________________
+ * | start | slave_addr + wr_bit + ack | write n bytes + ack  | stop |
+ * --------|---------------------------|----------------------|------|
+ *
+ */
+static esp_err_t i2c_master_write_slave(i2c_port_t i2c_num, uint8_t *data_wr, size_t size)
+{
+    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
+    i2c_master_start(cmd);
+    i2c_master_write_byte(cmd, (ESP_SLAVE_ADDR << 1) | WRITE_BIT, ACK_CHECK_EN);
+    i2c_master_write(cmd, data_wr, size, ACK_CHECK_EN);
+    i2c_master_stop(cmd);
+    esp_err_t ret = i2c_master_cmd_begin(i2c_num, cmd, 1000 / portTICK_RATE_MS);
+    i2c_cmd_link_delete(cmd);
+    return ret;
+}
+
+/**
+ * @brief i2c master initialization
+ */
+static esp_err_t i2c_master_init(void)
+{
+    int i2c_master_port = DEV_SHT20_I2C_NUM;
+    i2c_config_t conf;
+    conf.mode = I2C_MODE_MASTER;
+    conf.sda_io_num = DEV_SHT20_SDA_NUM;
+    conf.sda_pullup_en = GPIO_PULLUP_ENABLE;
+    conf.scl_io_num = DEV_SHT20_SCL_NUM;
+    conf.scl_pullup_en = GPIO_PULLUP_ENABLE;
+    conf.master.clk_speed = I2C_MASTER_FREQ_HZ;
+    i2c_param_config(i2c_master_port, &conf);
+    return i2c_driver_install(i2c_master_port, conf.mode, I2C_MASTER_RX_BUF_DISABLE, I2C_MASTER_TX_BUF_DISABLE, 0);
+}
+
+
+void init_sht20(void)
+{
+    static bool tmp = true;
+    if (tmp)
+    {
+        tmp = false;
+        ESP_ERROR_CHECK(i2c_master_init());
+    }
+}
+
+float get_sht20_Temperature(void)
+{
+    uint8_t data_rx[8] = {0};
+    uint8_t data_wr[8] = {0};
+    unsigned int dat = 0;
+    float temp = 0;
+
+    //懒加载
+    init_sht20();
+
+    data_wr[0] = HOLD_AT_START;
+    i2c_master_write_slave(DEV_SHT20_I2C_NUM, data_wr, strlen((char *)data_wr));
+    vTaskDelay(20 / portTICK_RATE_MS);
+
+    i2c_master_read_slave(DEV_SHT20_I2C_NUM, data_rx, 3);
+
+    if(!data_rx[0]&&!data_rx[1]){
+        return -1;
+    }
+
+    data_rx[1] &= 0xfc;
+    dat = (data_rx[0] << 8) | data_rx[1];
+
+    temp = ((float)dat * 175.72) / 65536.0 - 46.85; // ℃
+
+    ESP_LOGD(TAG, "temp=%.3f℃", temp);
+
+    return temp;
+}
+
+float get_sht20_Humidity(void)
+{
+
+    uint8_t data_rx[8] = {0};
+    uint8_t data_wr[8] = {0};
+    unsigned int dat = 0;
+    float temp = 0;
+
+    //懒加载
+    init_sht20();
+
+    data_wr[0] = HOLD_AH_START;
+    i2c_master_write_slave(DEV_SHT20_I2C_NUM, data_wr, strlen((char *)data_wr));
+    vTaskDelay(20 / portTICK_RATE_MS);
+
+    i2c_master_read_slave(DEV_SHT20_I2C_NUM, data_rx, 3);
+
+    if(!data_rx[0]&&!data_rx[1]){
+        return -1;
+    }
+
+    data_rx[1] &= 0xfc;
+    dat = (data_rx[0] << 8) | data_rx[1];
+
+    temp = (float)((dat * 125.0) / 65536.0 - 6); //%RH
+
+    ESP_LOGD(TAG, "hum=%.2f", temp);
+
+    return temp;
+}
diff --git a/21_s2_sht20/main/CMakeLists.txt b/21_s2_sht20/main/CMakeLists.txt
new file mode 100644
index 0000000..e012cd2
--- /dev/null
+++ b/21_s2_sht20/main/CMakeLists.txt
@@ -0,0 +1,6 @@
+# Slip client example
+
+idf_component_register(
+    SRCS "slip_client_main.c"
+    INCLUDE_DIRS "."
+)
diff --git a/21_s2_sht20/main/Kconfig.projbuild b/21_s2_sht20/main/Kconfig.projbuild
new file mode 100644
index 0000000..e23abfa
--- /dev/null
+++ b/21_s2_sht20/main/Kconfig.projbuild
@@ -0,0 +1,38 @@
+menu "Example Configuration"
+
+    menu "UART Configuration"
+        config EXAMPLE_UART_TX_PIN
+            int "TXD Pin Number"
+            default 4
+            range 0 36
+            help
+                Pin number of UART TX.
+
+        config EXAMPLE_UART_RX_PIN
+            int "RXD Pin Number"
+            default 36
+            range 0 36
+            help
+                Pin number of UART RX.
+
+        config EXAMPLE_UART_BAUD
+            int "UART baud rate"
+            default 115200
+            help
+                Baud rate for UART communication
+
+    endmenu
+
+    config EXAMPLE_UDP_PORT
+        int "Port for UDP echo server"
+        default 5678
+        help
+            Port for UDP echo server in example
+
+    config EXAMPLE_IPV4
+        bool "Test with IPv4 address"
+        default n
+        help
+            Test interface using IPv4
+
+endmenu
diff --git a/21_s2_sht20/main/component.mk b/21_s2_sht20/main/component.mk
new file mode 100644
index 0000000..a98f634
--- /dev/null
+++ b/21_s2_sht20/main/component.mk
@@ -0,0 +1,4 @@
+#
+# "main" pseudo-component makefile.
+#
+# (Uses default behaviour of compiling all source files in directory, adding 'include' to include path.)
diff --git a/21_s2_sht20/main/slip_client_main.c b/21_s2_sht20/main/slip_client_main.c
new file mode 100644
index 0000000..06e1820
--- /dev/null
+++ b/21_s2_sht20/main/slip_client_main.c
@@ -0,0 +1,30 @@
+/*
+ * @Author: your name
+ * @Date: 2020-09-27 10:09:49
+ * @LastEditTime: 2020-09-27 11:07:45
+ * @LastEditors: Please set LastEditors
+ * @Description: In User Settings Edit
+ * @FilePath: \esp-idf\examples\me\SHT20_ESP32S2\DEMO\main\slip_client_main.c
+ */
+#include <string.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+
+#include "esp_system.h"
+#include "esp_log.h"
+#include "esp_event.h"
+#include "esp_netif.h"
+#include "sht20.h"
+
+static const char *TAG = "SHT20_EXAMPLE";
+
+void app_main()
+{
+    while (true)
+    {
+        ESP_LOGI(TAG, "-----------------");
+        ESP_LOGI(TAG, "T=%.2f℃", get_sht20_Temperature());
+        ESP_LOGI(TAG, "H=%.2f%%", get_sht20_Humidity());
+        vTaskDelay(2000 / portTICK_RATE_MS);
+    }
+}
\ No newline at end of file