I C Precision Altimeter - Farnell

Flow chart for Polling or Interrupt - No FIFO
/* I2C Address is 0xC0 */
SlaveAddressIIC = 0xC0
/* Set to Altimeter with an OSR = 128 */
IIC_RegWrite(SlaveAddressIIC, 0x26, 0xB8);
/* Set INT to Active Low Open Drain */
IIC_RegWrite(SlaveAddressIIC, 0x28, 0x11);
/* Enable Data Flags in PT_DATA_CFG */
IIC_RegWrite(SlaveAddressIIC, 0x13, 0x07);
/* Enable DRDY Interrupt */
IIC_RegWrite(SlaveAddressIIC, 0x29, 0x80);
/* Set Active */
IIC_RegWrite(SlaveAddressIIC, 0x26, 0xB9);
Poll data or use
interrupt INT2
Interrupt
Check for interrupt
on pin INT2
No
Polling
Service interrupt
and clear
Yes
/* Set Active */
IIC_RegWrite(SlaveAddressIIC, 0x26, 0xB9);
/* Read INT_SOURCE */
INT_S = IIC_RegRead(SlaveAddressIIC, 0x12);
/* Read STATUS Register */
STA = IIC_RegRead(SlaveAddressIIC, 0x00);
/* Is Data Ready */
(STA & 0x08) == TRUE
No
No
/* Is SRC_DRDY Set */
(INT_S & 0x80) == TRUE
Yes
Yes
/* Read OUT_P and OUT_T */
/* This clears the DRDY Interrupt */
OUT_P_MSB = IIC_RegRead(SlaveAddressIIC, 0x01);
OUT_P_CSB = IIC_RegRead(SlaveAddressIIC, 0x02);
OUT_P_LSB = IIC_RegRead(SlaveAddressIIC, 0x03);
OUT_T_MSB = IIC_RegRead(SlaveAddressIIC, 0x04);
OUT_T_LSB = IIC_RegRead(SlaveAddressIIC, 0x05);
/* Read OUT_P and OUT_T */
/* This clears the DRDY Interrupt */
OUT_P_MSB = IIC_RegRead(SlaveAddressIIC, 0x01);
OUT_P_CSB = IIC_RegRead(SlaveAddressIIC, 0x02);
OUT_P_LSB = IIC_RegRead(SlaveAddressIIC, 0x03);
OUT_T_MSB = IIC_RegRead(SlaveAddressIIC, 0x04);
OUT_T_LSB = IIC_RegRead(SlaveAddressIIC, 0x05);
Clear Interrupt
Figure 5. Polling or Interrupt - No FIFO
MPL3115A2
Sensors
12 Freescale Semiconductor, Inc.