{"id":21071,"date":"2024-01-23T10:12:32","date_gmt":"2024-01-23T02:12:32","guid":{"rendered":"https:\/\/www.circuspi.com\/?p=21071"},"modified":"2024-01-23T10:12:33","modified_gmt":"2024-01-23T02:12:33","slug":"esp32-i2c-sht30-oled","status":"publish","type":"post","link":"https:\/\/www.circuspi.com\/index.php\/2024\/01\/23\/esp32-i2c-sht30-oled\/","title":{"rendered":"ESP32\u6559\u5b78\u7cfb\u5217(\u5341)\uff1aI2C\u8b80\u53d6SHT30\u6eab\u6fd5\u5ea6\u611f\u6e2c\u8207OLED\u986f\u793a"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

\u524d\u8a00<\/h2>\n\n\n\n

I\u00b2C\u662f\u4e00\u7a2e\u76f8\u7576\u5e38\u898b\u4e14\u6709\u540d\u7684\u50b3\u8f38\u5354\u8b70\uff0c\u5b83\u88ab\u5ee3\u6cdb\u7684\u61c9\u7528\u5728\u5404\u7a2e\u611f\u6e2c\u5668\u7684\u901a\u8a0a\u754c\u9762\u4e0a\u3002\u672c\u6587\u5c07\u8aaa\u660e\u5982\u4f55\u5c07ESP32\u64cd\u4f5c\u5728Master\u4ee5\u53caSlave Mode\u4e0b\uff0c\u4e26\u4ee5SHT3x\u6eab\u6ebc\u5ea6\u611f\u6e2c\u5668<\/a>\uff0c\u4ee5\u53ca1.3\u540bOLED\u986f\u793a\u5668\u70ba\u4f8b\uff0c\u8aaa\u660eESP32\u5982\u4f55\u5206\u5225\u4f7f\u7528\u9019\u5169\u500bI\u00b2C\u88dd\u7f6e\uff1b\u6700\u5f8c\u7d50\u5408\u5169\u8005\uff0c\u5c07\u6e2c\u91cf\u5230\u7684\u6eab\u6ebc\u5ea6\u6578\u503c\u986f\u793a\u5728OLED\u4e0a\u3002<\/p>\n\n\n\n

\u4ec0\u9ebc\u662fI2C<\/h2>\n\n\n\n

I\u00b2C\uff08\u5538\u4f5cI-Square-C\uff09\uff0c\u662f Inter-Integrated Circuit \u7684\u7e2e\u5beb\uff0c\u6709\u6642\u4e5f\u6703\u5beb\u4f5cIIC\u3001I2C \u6216 I\u00b2C bus\uff0c\u65bc1980\u5e74\u4ee3\u7531Philips\u516c\u53f8\uff08\u73fe\u70baNXP\uff09\u6240\u8a2d\u8a08\u51fa\u7684\u4e00\u7a2e\u901a\u8a0a\u5354\u8b70\uff0c\u6700\u521d\u7684\u76ee\u7684\u662f\u70ba\u4e86\u8b93\u540c\u4e00\u7247\u677f\u5b50\u4e0a\u7684\u5143\u4ef6\u53ef\u4ee5\u4e92\u76f8\u901a\u8a0a\u3002<\/p>\n\n\n\n

I\u00b2C\u662f\u4e00\u7a2e\u5177\u6709\u540c\u6b65\u8a0a\u865f\u7684\u4e32\u5217\u901a\u8a0a\u5354\u8b70\uff0c\u652f\u63f4\u591a\u500b\u4e3b\u5f9e\u8a2d\u5099\u9032\u884c\u96d9\u5411\u901a\u8a0a\uff0c\u5b83\u5141\u8a31\u7531\u4e00\u500b\u63a7\u5236\u5668\uff08Controller\uff09\u63a7\u5236\u591a\u500b\u5468\u908a\u8a2d\u5099\uff08Peripheral\uff09\uff0c\u4e5f\u53ef\u4ee5\u7531\u591a\u500b\u63a7\u5236\u5668\u63a7\u5236\u4e00\u500b\u5468\u908a\u8a2d\u5099\uff0c\u64c1\u6709\u9748\u6d3b\u7684\u67b6\u69cb\u662f\u5b83\u7684\u512a\u9ede\u4e4b\u4e00\u3002<\/p>\n\n\n\n

I\u00b2C\u7684\u53e6\u4e00\u500b\u512a\u9ede\u662f\u786c\u9ad4\u63a5\u7dda\u7c21\u55ae\uff0c\u53ea\u9700\u8981\u5169\u689d\u8a0a\u865f\u7dda(Bus)\u5c31\u80fd\u8207\u5176\u5b83\u88dd\u7f6e\u901a\u8a0a\uff0c\u9019\u9ede\u8207UART\u76f8\u540c\u3002\u4e0d\u540c\u7684\u662f\uff0cI\u00b2C\u53ef\u4ee5\u9023\u63a5\u591a\u500b\u8a2d\u5099\uff0c\u4e14\u4e0d\u8ad6\u662f\u4e3b\u8a2d\u5099\u6216\u662f\u5468\u908a\u8a2d\u5099\uff0c\u6240\u6709\u8a2d\u5099\u90fd\u5171\u4eab\u5169\u689d\u76f8\u540c\u7684\u8a0a\u865f\u7dda\uff08\u7a31\u4f5cBus\uff09\uff0c\u5206\u5225\u7528\u4f86\u50b3\u8f38\u8cc7\u6599(data)\u8207\u6642\u8108\u8a0a\u865f(clock)\u3002\u63a7\u5236\u5668\u53ef\u4ee5\u4f9d\u7167\u6bcf\u500b\u5468\u908a\u8a2d\u5099\u7684\u5730\u5740\u9078\u64c7\u8981\u9032\u884c\u901a\u8a0a\u7684\u5c0d\u8c61\uff0c\u6bcf\u500b\u5468\u908a\u8a2d\u5099\u90fd\u6709\u4e0d\u91cd\u8907\u76847\u4f4d\u5143\u5730\u5740\u3002\u5728\u5d4c\u5165\u5f0f\u61c9\u7528\u4e2d\uff0c\u8a31\u591a\u77ed\u8ddd\u96e2\u50b3\u8f38\u7684\u8a2d\u5099\u4e0a\u90fd\u4f7f\u7528I\u00b2C\u50b3\u8f38\u5354\u8b70\uff0c\u50cf\u662fOLED\u986f\u793a\u5668\u3001\u6578\u4f4d\u6eab(\u6ebc)\u5ea6\u611f\u6e2c\u5668\u3001DAC\u3001MPU6050\u3001LCD\u986f\u793a\u5668\u7b49\u90fd\u662f\u5e38\u898b\u7684\u5468\u908a\u88dd\u7f6e\u3002<\/p>\n\n\n\n

I\u00b2C\u7684\u57fa\u672c\u901a\u8a0a\u5354\u5b9a<\/h3>\n\n\n\n
\"\"<\/figure>\n\n\n\n

\u5982\u4f55\u5728ESP32\u4f7f\u7528I2C<\/h2>\n\n\n\n

I\u00b2C\u901a\u8a0a\u6642\u53ea\u9700\u4f7f\u7528\u5169\u689dBus\uff1aSDA\uff08serial data\uff09\u8207SCL\uff08serial clock\uff09\u3002SDA\u7528\u4f86\u50b3\u8f38\u8cc7\u6599\uff0cSCL\u5247\u662f\u7528\u4f86\u540c\u6b65\u8a2d\u5099\u901a\u8a0a\u7684\u6642\u8108\u8a0a\u865f\uff0c\u9019\u5169\u689dBus\u90fd\u4f7f\u7528open-drain\uff08\u6216\u662f open-collector\uff09\u7684\u96fb\u8def\u7d50\u69cb\u9a45\u52d5\u3002\u9019\u7a2e\u96fb\u8def\u7d50\u69cb\u4f7f\u5f97I\u00b2C\u53ef\u4ee5\u53ea\u7528\u4e00\u689d\u8cc7\u6599\u7dda\u5c31\u9054\u5230\u96d9\u5411\u50b3\u8f38\u7684\u529f\u80fd\uff0c\u4f46\u540c\u6642\u9019\u4e5f\u8868\u793a\u8a2d\u5099\u6c92\u6709\u81ea\u4e3b\u8f38\u51fa\u9ad8\u96fb\u58d3\u6e96\u4f4d\u7684\u9a45\u52d5\u80fd\u529b\u3002\u70ba\u4e86\u89e3\u6c7a\u9019\u500b\u554f\u984c\uff0c\u6211\u5011\u6703\u5728open-drain\u7684\u5916\u90e8\u96fb\u8def\u9023\u63a5\u4e0a\u62c9\u96fb\u963b\uff0c\u8b93\u8cc7\u6599\u7dda\u7684\u72c0\u614b\u7dad\u6301\u5728\u9ad8\u96fb\u4f4d\uff0c\u9019\u9ebc\u4e00\u4f86\u8a2d\u5099\u5c31\u53ef\u4ee5\u6309\u7167\u5be6\u969b\u60c5\u6cc1\u9078\u64c7\u4e0b\u62c9\uff08\u4f4e\u96fb\u4f4d\uff09\u6216\u91cb\u653e\u8cc7\u6599\u7dda\uff08\u9ad8\u96fb\u4f4d\uff09\u4f86\u6539\u8b8a\u96fb\u58d3\u6e96\u4f4d\u3002<\/p>\n\n\n\n

\u4e0a\u62c9\u96fb\u963b\u7684\u6578\u503c\u53ef\u4ee5\u7d93\u7531\u8a08\u7b97\u5f97\u51fa\uff0c\u901a\u5e385V\u7684\u8a2d\u5099\u6703\u4f7f\u75284.7k\u03a9\uff0c3V\u7684\u8a2d\u5099\u6703\u4f7f\u75282.4k\u03a9\u3002\u4e0d\u904e\uff0c\u5927\u90e8\u5206\u7684\u6a21\u7d44\u5728\u8a2d\u8a08\u6642\u90fd\u6709\u52a0\u5165\u4e0a\u62c9\u96fb\u963b\uff0c\u4f7f\u7528\u6642\u4e0d\u9700\u8981\u518d\u53e6\u5916\u9023\u63a5\u3002\u672c\u7bc7\u6240\u4f7f\u7528\u7684\u6a21\u7d44\u90fd\u4e0d\u9700\u8981\u52a0\u4e0a\u62c9\u96fb\u963b\uff0c\u53ea\u8981\u5c07\u5c0d\u61c9\u7684\u63a5\u8173\u9023\u63a5\u5728\u4e00\u8d77\u5c31\u53ef\u4ee5\u4e86\u3002<\/p>\n\n\n\n

\u7576\u6211\u5011\u4f7f\u7528Arduino IDE\u958b\u767c\u6642\uff0c\u9810\u8a2d\u7684SDA\u63a5\u8173\u662fGPIO 21\uff0cSDL\u63a5\u8173\u662fGPIO 22\u3002<\/p>\n\n\n\n

<\/p>\n\n\n\n

I2C\u8a2d\u5099<\/th>ESP32<\/th><\/tr><\/thead>
VCC<\/td>3.3V\/5V<\/td><\/tr>
GND<\/td>GND<\/td><\/tr>
SDA<\/td>SDA (GPIO 21)<\/td><\/tr>
SCL<\/td>SCL (GPIO 22)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

ESP32\u7684I\u00b2C\u4ecb\u9762\u53ef\u4ee5\u505a\u70ba\u4e3b\u63a7\u7aef\uff08Master Mode\uff09\u6216\u662f\u505a\u70ba\u5468\u908a\u8a2d\u5099\uff08Slave Mode\uff09\u4f7f\u7528\u3002\u591a\u6578\u60c5\u6cc1\u4e0bESP32\u90fd\u6703\u505a\u70ba\u4e3b\u63a7\u7aef\uff0c\u642d\u914d\u5468\u908a\u611f\u6e2c\u5668\/\u6a21\u7d44\u4f7f\u7528\u3002\u82e5\u60f3\u77ad\u89e3\u5982\u4f55\u7576\u4f5c\u5468\u908a\u8a2d\u5099\u4f7f\u7528\uff0c\u53ef\u4ee5\u81ea\u884c\u53c3\u8003Arduino IDE\u4e2d\u7684\u7bc4\u4f8b\u7a0b\u5f0f (File>Examples>Wire>WireMaster,WireSlave)\u3002\u5728\u4f7f\u7528I\u00b2C\u6a21\u7d44\u6642\uff0c\u901a\u5e38\u4e5f\u90fd\u8981\u53e6\u5916\u5b89\u88dd\u51fd\u5f0f\u5eab\uff0c\u8207I\u00b2C\u5354\u8b70\u901a\u8a0a\u904e\u7a0b\u7684\u95dc\u806f\u5ea6\u8f03\u4f4e\uff0c\u6240\u4ee5\u4e0b\u9762\u63a5\u7d39\u7d30\u7bc0\u90e8\u5206\u7684\u5167\u5bb9\u50c5\u63d0\u4f9b\u7d66\u6709\u8208\u8da3\u7684\u8b80\u8005\u53c3\u8003\u3002\u82e5\u60f3\u77ad\u89e3\u5982\u4f55\u4f7f\u7528SHT3x\u6eab\u6ebc\u5ea6\u611f\u6e2c\u5668<\/a>\u548cOLED\uff0c\u53ef\u4ee5\u76f4\u63a5\u8df3\u5230\u7bc4\u4f8b\u90e8\u5206\u3002<\/p>\n\n\n\n

<\/p>\n\n\n\n

Master Mode<\/h3>\n\n\n\n

\u6211\u5011\u901a\u5e38\u6703\u5c07ESP32\u7576\u4f5c\u4e3b\u63a7\u7aef\u9023\u63a5\u5404\u9805\u611f\u6e2c\u5668\u6216\u63a7\u5236\u5176\u5b83\u7684\u5468\u908a\u8a2d\u5099\uff0c\u9019\u6642\u5019ESP32\u5c31\u6703\u64cd\u4f5c\u5728Master mode\u4e0b\uff0c\u53ef\u4ee5\u5c0d\u5468\u908a\u8a2d\u5099\u767c\u8d77\u3001\u7d50\u675f\u50b3\u8f38\uff0c\u6216\u662f\u8b80\u53d6\u5468\u908a\u8a2d\u5099\u56de\u50b3\u7684\u5167\u5bb9\u3002<\/p>\n\n\n\n

\u4f7f\u7528\u7bc4\u4f8b<\/strong><\/p>\n\n\n\n

\u95dc\u65bcMaster Mode\u5177\u9ad4\u7684\u4f7f\u7528\u7bc4\u4f8b\u53ef\u4ee5\u5728Arduino IDE\u7684File>Examples>Wire>WireMaster\u4e2d\u627e\u5230<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

\u4e0b\u9762\u662f\u95dc\u65bcMaster Mode \u50b3\u8f38\u76f8\u95dcAPI\u7684\u8aaa\u660e\uff1a<\/p>\n\n\n\n

    \n
  • begin<\/strong><\/li>\n<\/ul>\n\n\n\n

    \u4f7f\u7528\u9810\u8a2dI\u00b2C\u63a5\u8173\u7684\u8a71\uff0c\u5728setup()\u4e2d\u547c\u53ebWire.begin()\u5373\u53ef<\/p>\n\n\n\n

    void setup() {\n  Wire.begin();\n}<\/code><\/pre>\n\n\n\n
    \u5982\u679c\u8981\u4f7f\u7528\u5176\u4ed6\u63a5\u8173\uff0c\u53ef\u4ee5\u5728begin()\u524d\u52a0\u4e0asetPins()\uff0c\u4e26\u5c07\u6307\u5b9a\u7684\u63a5\u8173\u7576\u4f5c\u53c3\u6578\u50b3\u5165\uff1a<\/p>\n\n\n\n
    #define I2C_SDA 4\n#define I2C_SCL 5\n\nvoid setup() {\n  Wire.setPins(I2C_SDA, I2C_SCL);\n  Wire.begin();\n}<\/code><\/pre>\n\n\n\n
      \n
    • beginTransmission<\/strong><\/li>\n<\/ul>\n\n\n\n
      beginTransmission<\/span><\/code><\/code>\u7528\u4f86\u5c0d\u5468\u908a\u8a2d\u5099\u767c\u8d77\u50b3\u8f38<\/p>\n\n\n\n
      \u51fd\u5f0f\u539f\u578b\uff1a\nvoid beginTransmission(uint16_t address)\n\n\u4f7f\u7528\u7bc4\u4f8b\uff1a\nWire.beginTransmission(0x55);<\/code><\/pre>\n\n\n\n
      \u53c3\u6578\u8aaa\u660e\uff1a<\/p>\n\n\n\n
      address: \u5468\u908a\u8a2d\u5099\u7684I2C\u5730\u5740<\/p>\n\n\n\n
        \n
      • write<\/strong><\/li>\n<\/ul>\n\n\n\n
        write<\/span><\/code><\/code>\u53ef\u4ee5\u5c07\u8cc7\u6599\u5beb\u5165\u7de9\u885d\u5340(buffer)\uff0c\u5b83\u6703\u56de\u50b3\u5167\u6dfb\u52a0\u5230\u7de9\u885d\u5340\u7684\u8cc7\u6599\u5927\u5c0f\u3002<\/p>\n\n\n\n
        \u51fd\u5f0f\u539f\u578b\uff1a\nsize_t write(uint8_t);\n\n\u4f7f\u7528\u7bc4\u4f8b\uff1a\nWire.write(x);<\/code><\/pre>\n\n\n\n
          \n
        • endTransmission<\/strong><\/li>\n<\/ul>\n\n\n\n
          \u4f7f\u7528endTransmission<\/span><\/code><\/code>\u5c07\u8cc7\u6599\u5f9e\u7de9\u885d\u5340\u767c\u9001\u5230\u5468\u908a\u8a2d\u5099\uff0c\u4e26\u7d50\u675f\u50b3\u8f38\u3002\u9019\u500b\u51fd\u5f0f\u6703\u56de\u50b3\u932f\u8aa4\u4ee3\u78bc(error code)<\/p>\n\n\n\n
          \u51fd\u5f0f\u539f\u578b\uff1a\nuint8_t endTransmission(bool sendStop);\n\n\u4f7f\u7528\u7bc4\u4f8b\uff1a\nWire.endTransmission(true);<\/code><\/pre>\n\n\n\n
          \u53c3\u6578\u8aaa\u660e\uff1a<\/p>\n\n\n\n
          sendStop: \u555f\u7528 (true) \u6216\u505c\u7528 (false) \u505c\u6b62\u7684\u8a0a\u865f\u3002\u9810\u8a2d\u53c3\u6578\u70batrue\u3002<\/p>\n\n\n\n
          error code:<\/p>\n\n\n\n
          \/\/ error code\ntypedef enum {\n    I2C_ERROR_OK=0,\n    I2C_ERROR_DEV,\n    I2C_ERROR_ACK,\n    I2C_ERROR_TIMEOUT,\n    I2C_ERROR_BUS,\n    I2C_ERROR_BUSY,\n    I2C_ERROR_MEMORY,\n    I2C_ERROR_CONTINUE,\n    I2C_ERROR_NO_BEGIN\n} i2c_err_t;<\/code><\/pre>\n\n\n\n
            \n
          • requestFrom<\/strong><\/li>\n<\/ul>\n\n\n\n
            \u5982\u679c\u8981\u8b80\u53d6\u88dd\u7f6e\u56de\u50b3\u7684\u5167\u5bb9\uff0c\u53ef\u4ee5\u547c\u53ebrequestFrom<\/span><\/code><\/code>\u5b83\u6703\u56de\u50b3\u8b80\u53d6\u5230\u7684\u8cc7\u6599\u5927\u5c0f(number of bytes)\u3002<\/p>\n\n\n\n
            \u51fd\u5f0f\u539f\u578b\uff1a\nuint8_t requestFrom(uint16_t address, uint8_t size, bool sendStop)\n\n\u4f7f\u7528\u7bc4\u4f8b\uff1a\nWire.requestFrom(0x55, 16);<\/code><\/pre>\n\n\n\n
            \u53c3\u6578\u8aaa\u660e\uff1a<\/p>\n\n\n\n
            address: \u5468\u908a\u8a2d\u5099\u7684I2C\u5730\u5740<\/p>\n\n\n\n
            size: \u6240\u9700\u7684\u8a18\u61b6\u9ad4\u5927\u5c0f<\/p>\n\n\n\n
            sendStop: \u555f\u7528 (true) \u6216\u505c\u7528 (false) \u505c\u6b62\u7684\u8a0a\u865f\u3002\u9810\u8a2d\u53c3\u6578\u70batrue<\/p>\n\n\n\n
              \n
            • readBytes<\/strong><\/li>\n<\/ul>\n\n\n\n
              readBytes<\/span><\/code><\/code>\u7528\u4f86\u67e5\u770b\u8cc7\u6599<\/p>\n\n\n\n
              \u51fd\u5f0f\u539f\u578b\uff1a\nvirtual size_t readBytes(char *buffer, size_t length);\n\n\u4f7f\u7528\u7bc4\u4f8b\uff1a\nuint8_t bytesReceived = Wire.requestFrom(0x55, 16);\nuint8_t temp[bytesReceived];\n\nWire.readBytes(temp, error);<\/code><\/pre>\n\n\n\n
              <\/p>\n\n\n\n
              \u5982\u4f55\u6383\u63cfI2C\u8a2d\u5099\u5730\u5740<\/h2>\n\n\n\n
              I\u00b2C bus\u4e0a\u7684\u5468\u908a\u8a2d\u5099\u90fd\u6703\u6709\u4e00\u7d44\u752816\u9032\u4f4d\u8868\u793a\u7684\u8a2d\u5099\u5730\u5740\uff0c\u901a\u5e38\u5730\u5740\u6703\u6a19\u8a3b\u5728\u6a21\u7d44\u4e0a\u3002\u5728\u4f7f\u7528\u8a2d\u5099\u524d\uff0c\u6211\u5011\u53ef\u4ee5\u5148\u6383\u63cf\u4e00\u6b21\uff0c\u4ee5\u78ba\u8a8d\u8a2d\u5099\u5be6\u969b\u7684\u5730\u5740\u3002<\/p>\n\n\n\n