diff --git a/lib/max31856/max31856.c b/lib/max31856/max31856.c
new file mode 100644
--- /dev/null
+++ b/lib/max31856/max31856.c
@@ -0,0 +1,148 @@
+//
+// MAX31856: Driver to configure and read temperature from the MAX31856 thermoouple-to-Digital IC
+//
+
+#include "max31856.h"
+#include "states.h"
+#include "error.h"
+
+// Private variables
+static float temp_latest = 0.0;
+static float temp_avg = 0.0;
+
+static SPI_HandleTypeDef* spiport;
+static GPIO_TypeDef* csport;
+static uint32_t cspin;
+
+
+// Private prototypes
+static void __cs_assert(void);
+static void __cs_deassert(void);
+static void __write_reg(uint8_t reg, uint8_t data);
+static void __read_reg(uint8_t reg, uint8_t* rxbuf, uint8_t len);
+
+
+// Initialize the MAX31856 driver
+void max31856_init(SPI_HandleTypeDef* spi_port, GPIO_TypeDef* cs_port, uint32_t cs_pin, uint32_t sensor_type)
+{
+	// Set CS pin references
+	csport = cs_port;
+	cspin = cs_pin;
+
+	// Set SPI port reference
+	spiport = spi_port;
+
+	// Configure the CS pin for output
+	GPIO_InitTypeDef GPIO_InitStruct;
+	GPIO_InitStruct.Pin = cs_pin;
+	GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
+	GPIO_InitStruct.Pull = GPIO_NOPULL;
+	GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
+	HAL_GPIO_Init(cs_port, &GPIO_InitStruct);
+
+	// MAX31856
+	// - set to continuous conversion mode
+	// - probably no filtering, we'll do that on this side of things
+	// - set up to read the typical open/short faults but not the high/low alarms
+
+
+	// TODO: Enable open/short detection
+	// Enables auto conv
+	__write_reg(MAX31856_CR0_REG, MAX31856_CR0_OCFAULT0 | MAX31856_CR0_AUTOCONVERT);
+
+	// Averaging set to 1 sample, TC type set to K
+	__write_reg(MAX31856_CR1_REG, MAX31856_TCTYPE_K);
+
+	// sensor type - could we just mask bits off? maybe optimize the enum for this
+}
+
+
+// Pull reading from the MAX31856 IC
+void max31856_process(void)
+{
+	uint8_t tempbuf[4];
+	__read_reg(MAX31856_LTCBH_REG, tempbuf, 3);
+
+
+	int32_t temp24 = tempbuf[0] << 16 | tempbuf[1] << 8 | tempbuf[0];
+	if (temp24 & 0x800000) {
+		temp24 |= 0xFF000000;  // fix sign
+	}
+
+	temp24 >>= 5;  // bottom 5 bits are unused
+
+	float tempfloat = temp24;
+	tempfloat *= 0.0078125;
+
+	return tempfloat;
+
+
+
+
+	// Read temperature from the MAX31856 (approx 10hz optimally)
+	uint8_t data[] = {0,0,0,0};
+	HAL_SPI_Transmit(spiport, data, 1, 100);
+
+}
+
+
+// Return latest temperature reading (unaveraged, deg C)
+float max31856_latest_temp(void)
+{
+	return temp_latest;
+}
+
+
+// Return average temperature reading (deg C)
+float max31856_avg_temp(void)
+{
+	return temp_latest;
+}
+
+
+static void __write_reg(uint8_t reg, uint8_t data)
+{
+	// Set write bit
+	reg |= MAX31856_WRITE_BIT;
+
+	uint8_t outarr[2] = {reg, data};
+
+	// Assert the bus
+	__cs_assert();
+
+	// Write data
+	HAL_SPI_Transmit(spiport, outarr, 2, 100);
+
+	// Release the bus
+	__cs_deassert();
+}
+
+static void __read_reg(uint8_t reg, uint8_t* rxbuf, uint8_t len)
+{
+	// Transmit buffer only uses first item for reg addr
+	uint8_t regarr[1] = {reg};
+
+
+	// Assert the bus
+	__cs_assert();
+
+	// Send address
+	HAL_SPI_Transmit(spiport, regarr, 1, 100);
+
+	// Receive data
+	HAL_SPI_Receive(spiport, rxbuf, len, 100);
+
+	// Release bus
+	__cs_deassert();
+
+}
+
+static void __cs_assert(void)
+{
+	HAL_GPIO_WritePin(csport, cspin, 0);
+}
+
+static void __cs_deassert(void)
+{
+	HAL_GPIO_WritePin(csport, cspin, 1);
+}