4.3.3 Temperature Sensor
I/O1 Xplained Pro extension board features an Atmel AT30TSE758 temperature sensor chip with an 8kb serial EEPROM inside. The sensor includes programmable high and low temperature alarms, user-selectable temperature resolution up to 12 bits, and an I2C/SMBus™ compatible serial interface.
| Pin on EXT connector | Pin name | AT30TSE758 temperature sensor pin | Comment |
|---|---|---|---|
| 11 | SDA | 1 | Data line of serial interface |
| 12 | SCL | 2 | Clock line of serial interface |
| 9 | ALERT | 3 | Temperature alarm signalling pin |
| GND | GND | 4 | |
| - | A2 | 5 | Address line for serial interface, by default pulled high |
| - | A1 | 6 | Address line for serial interface, by default pulled high |
| - | A0 | 7 | Address line for serial interface, by default pulled high |
| VCC | VCC | 8 |
The temperature sensor has two TWI addresses; one for the temperature sensor and one for the EEPROM. The addresses are "0b1001 A2 A1 A0" for the temperature sensor and "0b1010 A2 A1 A0" for the EEPROM. The address selection lines (A2, A1, and A0) of the temperature sensor chip is by default pulled high through 100kΩ resistors, which makes the default addresses 0b1001111 and 0b1010111. Soldering the straps on the back of the I/O1 Xplained Pro board for An will alter that bit in the address to zero. Each strap is marked in silkscreen with A0, A1, and A2 as shown in the picture below. When communicating with the EEPROM parts of the TWI address is used as a page address. For more details, see the device (AT30TSE752A/754A/758A) datasheet.
