arduino i2c的wire库使用求教

arduino i2c\u7684wire\u5e93\u4f7f\u7528\u6c42\u6559

http://arduino.cc/en/Reference/Wire
\u5f00\u4e2a google \u7ffb\u8bd1,\u6216\u8005 \u5fc5\u5e94\u7ffb\u8bd1 \u6700\u591a1~2\u949f\u5c31\u80fd\u770b\u61c2.

\u7ed9\u4f60\u4e00\u4e2a DS1307 \u7684\u4f8b\u5b50. \u524d\u63d0\u662fDS1307 \u5185\u5df2\u7ecf\u6709\u8bbe\u597d\u4e86\u65f6\u95f4.
#include #define DS1307_I2C_ADDRESS0x68#define REG_SEC 0x00#define REG_MIN 0x01#define REG_HOUR0x02#define REG_DAY 0x03#define REG_DATE0x04#define REG_MON 0x05#define REG_YEAR0x06#define REG_CTL 0x07#define REG_RAM_START0x08#define REG_RAM_END 0x3Fvoid setup() {Wire.begin();// \u5f00\u542f I2C \u603b\u7ebf(\u4e3b\u8bbe\u5907)Serial.begin(9600);}void loop() {Wire.beginTransmission(DS1307_I2C_ADDRESS);// \u5f00\u542f\u53d1\u9001 Wire.write(REG_SEC);// \u5199\u5165 DS1307 \u79d2\u5730\u5740 Wire.endTransmission();//\u7ed3\u675f\u53d1\u9001 Wire.requestFrom(DS1307_I2C_ADDRESS, 1); // \u8bf7\u6c42 DS1307 \u4e00\u4e2a\u5b57\u8282 uint8_t s; if(Wire.available() == 1) { // \u53ef\u5426\u83b7\u53d61\u4e2a\u6570\u636e s = bcd2dec(Wire.read() & 0x7F); // \u8bfb\u53d6 DS1307 \u79d2 Serial.println(s); } delay(1000);}uint8_t dec2bcd(uint8_t dec) { return ((dec/10 * 16) + (dec % 10));}uint8_t bcd2dec(uint8_t bcd) { return ((bcd/16 * 10) + (bcd % 16));}

\u3000\u3000\u5f00\u4e2a google \u7ffb\u8bd1,\u6216\u8005 \u5fc5\u5e94\u7ffb\u8bd1 \u6700\u591a1~2\u949f\u5c31\u80fd\u770b\u61c2.

\u3000\u3000\u7ed9\u4f60\u4e00\u4e2a DS1307 \u7684\u4f8b\u5b50. \u524d\u63d0\u662fDS1307 \u5185\u5df2\u7ecf\u6709\u8bbe\u597d\u4e86\u65f6\u95f4.

\u3000
\u3000\u3000
\u3000\u3000#include
\u3000\u3000
\u3000\u3000#define DS1307_I2C_ADDRESS 0x68
\u3000\u3000
\u3000\u3000#define REG_SEC 0x00
\u3000\u3000#define REG_MIN 0x01
\u3000\u3000#define REG_HOUR 0x02
\u3000\u3000#define REG_DAY 0x03
\u3000\u3000#define REG_DATE 0x04
\u3000\u3000#define REG_MON 0x05
\u3000\u3000#define REG_YEAR 0x06
\u3000\u3000#define REG_CTL 0x07
\u3000\u3000
\u3000\u3000#define REG_RAM_START 0x08
\u3000\u3000#define REG_RAM_END 0x3F
\u3000\u3000
\u3000\u3000void setup() {
\u3000\u3000Wire.begin(); // \u5f00\u542f I2C \u603b\u7ebf(\u4e3b\u8bbe\u5907)
\u3000\u3000Serial.begin(9600);
\u3000\u3000}
\u3000\u3000
\u3000\u3000void loop() {
\u3000\u3000Wire.beginTransmission(DS1307_I2C_ADDRESS); // \u5f00\u542f\u53d1\u9001
\u3000\u3000Wire.write(REG_SEC); // \u5199\u5165 DS1307 \u79d2\u5730\u5740
\u3000\u3000Wire.endTransmission(); // \u7ed3\u675f\u53d1\u9001
\u3000\u3000
\u3000\u3000Wire.requestFrom(DS1307_I2C_ADDRESS, 1); // \u8bf7\u6c42 DS1307 \u4e00\u4e2a\u5b57\u8282
\u3000\u3000
\u3000\u3000uint8_t s;
\u3000\u3000if(Wire.available() == 1) { // \u53ef\u5426\u83b7\u53d61\u4e2a\u6570\u636e
\u3000\u3000s = bcd2dec(Wire.read() & 0x7F); // \u8bfb\u53d6 DS1307 \u79d2
\u3000\u3000Serial.println(s);
\u3000\u3000}
\u3000\u3000delay(1000);
\u3000\u3000}

\u3000\u3000uint8_t dec2bcd(uint8_t dec) {
\u3000\u3000return ((dec/10 * 16) + (dec % 10));
\u3000\u3000}
\u3000\u3000
\u3000\u3000uint8_t bcd2dec(uint8_t bcd) {
\u3000\u3000return ((bcd/16 * 10) + (bcd % 16));
\u3000\u3000}

在使用Wire.h函式库时,如看IC规格书时，装置位址格式中的最後的一个 bit(读/写位元) 我们必须忽略它(因为在使用Wire.h库函式时这个读/写位元的值它会自动帮你填上，虽然我们在写sketch代码时看不到)
所以-我们要将 读/写位元 忽略它拿掉(楼主用的方式是将整个位址右移，或是直接用人脑除以2後答案填上 都行)後 一定会变成7个bit的装置位址，也符合I2C装置位址规范(0~127)

有例程的呀

扩展阅读：www.vivo.com ... arduino mega 2560 ... arduino max6675 ... vivo x70 pro ... arduino 485 i2c ... vivo y52s ... arduino ina219 ... arduino nano vin ... arduino switch ...