Datasheet

Pinouts

The MAX31865 is a tiny surface mount chip, and it needs a lot of other parts to make it work, so we've got it on a nice

breakout board for you. You can control the chip and read data from it using the breakouts at the bottom. Let's go thru

these!

Power Pins:

Vin - this is the power pin. Since the chip uses 3 VDC, we have included a voltage regulator on board that will

take 3-5VDC and safely convert it down. To power the board, give it the same power as the logic level of your

microcontroller - e.g. for a 5V micro like Arduino, use 5V

3Vo - this is the 3.3V output from the voltage regulator, you can grab up to 100mA from this if you like

GND - common ground for power and logic

SPI Logic pins:

All pins going into the breakout have level shifting circuitry to make them 3-5V logic level safe. Use whatever logic

level is on Vin!

SCK - This is the SPI Clock pin, its an input to the chip

SDO - this is the Serial Data Out / Master In Slave Out pin, for data sent from the MAX31865 to your processor

SDI - this is the Serial Data In / Master Out Slave In pin, for data sent from your processor to the MAX31865

CS - this is the Chip Select pin, drop it low to start an SPI transaction. Its an input to the chip

If you want to connect multiple MAX31865's to one microcontroller, have them share the SDI, SDO and SCK pins. Then

assign each one a unique CS pin.

RDY (Ready) - is a data-ready indicator pin, you can use this pin to speed up your reads if you are writing your

own driver. Our Arduino driver doesn't use it to save a pin