===== How to Access Ram ===== Each I2C device has an address. The DS1307 chip address is 0x68. The Ram on the device starts at address 0x08. The first 7 locations are the RTC.\\ {{:rtc_registers.jpg?600|}} To get to the start of RAM, use the following code: Wire.beginTransmission(DS1307_ADDRESS); Wire.send(8); Wire.endTransmission(); This will set the I2C address to 0x68, the DS1307 Address.\\ The second line sets the register index to 8, the start of RAM.\\ The third line, Wire.endTransmission(); , transmits the sequence.\\ Subsequent reads from the chip will start at 8. For example, to read 4 bytes from the chip:\\ Wire.requestFrom(DS1307_ADDRESS, 4); The above line will put the 4 bytes into the receive buffer. To fetch the bytes: while(Wire.available()) // slave may send less than requested { byte c = Wire.receive(); // receive a byte as character Serial.print(c, HEX); // print the character Serial.print(" "); }