User Manual

Application Note
SMBus communication with MLX90614
390119061402 Page 19 of 32 Jan-2008
Rev 004
The format of SMBus writing in EEPROM is:
In Application mode only 9 cells are accessible for writing. An attempt to write not accessible
EEPROM cell results in no change.
Before writing an erasing operation must be done. An erasing operation is just a writing of zeros
in an EEPROM cell. After a/an writing/erasing 5ms are need the new value to be written/erased.
After writing it is strongly recommended that the device is restarted by turning off/on the power
supply or by putting the sensor in/out sleep.
Pseudo code example:
An Erasing of the EEPROM address 0x0E (SMBus Address)
1. Send START bit
2. Send Slave Address (0x00* for example) + Rd\-Wr bit**
3. Send Command (0b001x_xxxx + 0b0000_1110 -> 0b0010_1110)
4. Send Low data 0x00
5. Send High data 0x00
6. Send PEC 0x6F
7. Send STOP bit
8. Wait 5ms (this time is need the cell to be erased)
A writing of 0x5A in EEPROM address 0x0E (SMBus Address )
1. Send START bit
2. Send Slave Address (0x00* for example) + Rd\-Wr bit**
3. Send Command (0b001x_xxxx + 0b0000_1110 -> 0b0010_1110)
4. Send Low Byte 0x5A
5. Send High Byte 0x00 (the high byte of the EEPROM address 0x0E has no meaning)
6. Send PEC 0xE1
7. Send STOP bit
8. Wait 5ms (this time is need the cell to be written)
9. Turn off/Turn on module power supply to reset MLX90614 (After this MLX90614 will
respond to the new slave address 0x5A)***
Note* : Any MLX90614 will respond to address 0x00
Note**: Bit Rd\-Wr has no meaning for MLX90614
Note***: Put in/Put out a MLX90614 in/from Sleep Mode also resets MLX90614